Estimate cost of replacing chain tensioners on XJ8..
Discussion
ZF Gearbox oil change is easy once you know how. Essential to work spotlessly clean.
Crack off gearbox sump bolts and filler plug. Drain oil and remove sump pan.
Remove filter, fit new, clean out sump pan and replace.
Initial oil fill to level of filler hole so it overflows a little.
Start engine and have assistant repeatedly cycle slowly through D N R.
Quickly pump more oil in with engine still running so it overflows from filler hole again.
With engine still running fit filler plug.
Labour for secondary timing chain tensioner swap should be 3 hours absolute max.
I wrote this buyers guide a while ago. Hopefully it'll help.
X308 OVERVIEW
To avoid XJ model confusion the 1997-2002 V8 engined XJ is referred to by its factory designation as the X308. The V8 engine in the 308 is available in a 3.2, 4.0 with VVT and a supercharged 4.0 and all versions are 5 speed auto only. £3000 should buy you a good example of a base 3.2, but the best low mileage cars or high spec ones are priced at up to double that. Engines were revised in late 1999 model year from AJ26 version to AJ27. A car fitted with the revised engine version can be identified by a VIN number ending in five, not six digits.
AJ26 cars had weak water pumps, secondary timing chain tensioners, throttle bodies and a Nicasil coating applied directly on the aluminum block bore walls rather than using conventional liners pressed into the block.
ENGINE NICASIL
Some Nicasil coatings suffered from bore erosion due to a combination of high Sulphur content fuel and repeated short trips. Sulphur maximum allowable limits in petrol were lowered considerably in Jan 2000 so any pre 2000 Nicasil coated V8 engine that's still OK now should be fine forever. Several Nicasil lined engines were changed under warranty so you may find a pre 2000 car with a later steel lined engine fitted - identify this by the presence of a green tag on the head buried at the back of the RH bank and the engine change should also be recorded in the history. Symptoms of bore erosion and loss of compression are poor cold starting, a lumpy idle and heavy oil deposits in the breather system and air intake. Crankcase pressure will be high too – a quick check for this is to slightly lift the oil filler cap at hot idle. There should be little or no internal pressure or fumes escaping. Jaguar dealers can perform a blow by check to determine engine condition. A good condition engine will show less than 25 l/m, anything over 40 l/m will make a good Top Gear coffee table.
ENGINE COOLING
Impellors on AJ26 water pumps can disintegrate giving a loss of efficiency leading to overheating and potential head gasket failure. An early pump can be changed to the later version with a metal, not plastic impeller. The temperature gauge is software driven and is not always an accurate refection of actual coolant temperature.
For an indication of water pump efficiency, remove the coolant header tank cap when the engine is STONE COLD, start up and gently increase engine speed. If the water pump is healthy you should see a steady stream of coolant into the tank from the thin return pipe that runs back from the front of the engine.
You may be able to identify the later type of pump by the presence of a black plastic, not metal gasket, but the only certain way is to remove the pump and have a look. Spring type coolant hose clips can loose tension and allow pipes to blow off and some plastic parts on the hoses, unions and thermostat housing are delicate. It’s worth replacing all the sprung coolant clips with proper Jubilee ones. Check all over for evidence of coolant leaks, particularly around the thermostat/filler cap tower and coolant (valley) pipes underneath the inlet manifold. Occasional auxiliary heater pump failures can lead to no heat output in the cabin at low engine RPM. Cycle the whole climate and a/c system through all vent operations and temperature range. Two types of coolant available for the XJ - don’t mix the later orange long life one with the earlier type.
ENGINE THROTTLE BODIES
AJ26 throttle bodies ought to have been changed to the later design under a factory safety recall. Some of the early bodies suffered from failing actuating motors causing to the engine to cut out completely on the overrun. The later design should have been factory fitted to all cars from VIN 043775 onwards.
SECONDARY TIMING CHAIN TENSIONERS AND CHAINS
The only post AJ26 revision engine issue is the secondary timing chain tensioners. These were revised to a mk 2 version around the same time as the rest of the 1999 engine revisions but the mk 2 type still had a plastic body which can crack or break up leading to slipped or broken chains. Mk 1 tensioners are actuated by engine oil pressure and failure can often be identified by a sharp rattling noise similar to a bicycle chain dragging on the chain guard on a cold start. The mk2 type is permanently tensioned by an integral spring instead which means it’ll usually fail silently.
A permanent solution is to retro-fit the later mk3 version tensioner made with a metal, not plastic body from the later 4.2 incarnation of the V8 engine and the only way to be sure of which tensioners are fitted to an 308 is to either have a receipt with tensioner part numbers C2A1511 and C2A1512 which are the metal bodied type and the required 4 new bolts to fit them on it relating to that particular car or remove the RH cam cover - the LH is a PITA to get off - and have a look. A reddish/orange (mk1) or cream (mk2) plastic tensioner body is bad news, a grey aluminum metal one (mk3) is good.
The cam phasing on the V8 means the timing gear works hard and timing chains can stretch at high mileages or on neglected cars. If this is identified then a full chain and tensioner replacement is required costing up to £1000. If the chains/sprockets and guides are OK then it’s a wise precaution to fit the mk3 secondary tensioners which is a fairly easy DIY job. Tensioners cost around £75 a set plus a couple of quid for new bolts. Cam setting tools for this job and all other special tools needed for any work on a 308 can all be hired from the Jaguar Enthusiasts’ Club. Secondary tensioners can also be changed without any tools by removing the exhaust cam whilst preserving the timing with a tie wrap holding the chain on the ex cam sprocket and easing the tensioners out of location.
Exhaust cam chains slipping one tooth – usually on a cold start - will give a very rough running engine, more than one tooth slipped means exhaust valves will meet pistons.
A good general rule of thumb for engine condition is internal cleanliness. Bright shiny metal inside the oil filler cap and dipstick along with clean oil and no evidence of leaks is a good sign, as is clear coolant that does not smell or taste bitter or acrid.
GEARBOX/ DRIVELINE
All X308s have a “sealed for life” gearbox – ZF unit in the n/a cars and a Mercedes one in the supercharged cars. Loads have failed now - just look on ebay in the non runners or spares and repairs section. Any car that hesitates or engages Drive with a jerk or thump as the engine speed rises has a potential gearbox failure looming. Gear changes should be seamless and quiet and you should be able to play tunes with the throttle, Sport switch and J gate selector. Any car stuck in 4th or 5th is FUBAR’d.
A very faint gear whine may be heard in intermediate gears. Any gearbox issues or concerns are potentially fatal. An oil and filter change may be all that’s needed to cure a gearbox malfunction but that’s never guaranteed.
Ideally the gearbox oil and filter should be changed at 50k then at 25k intervals; it's not a simple drain and refill on the ZF box as the final fill has to be done quickly with the engine running and within a narrow temperature range. There is no conventional dipstick for checking oil level.
The ZF 5 speed box on the n/a cars requires Esso/Mobil longlife LT 71141 fluid also known as Lifeguard Fluid 5 and not conventional Dexron 3. The Mercedes gearbox in the supercharged version is also sealed for life but the same change requirement apply although you can use Dexron 3 in this box and once you’ve fitted a temporary dipstick it’s a much less complex job to do. Some transmission specialists offer a flush and change service done via the rather fragile oil cooler pipes in the radiator which also gets the oil otherwise retained in the torque converter out.
The same applies to the rear axle. Oil should be changed but there’s no drain plug. Old oil has to be vacuum extracted out of the filler plug. Refill with a API GL5 75 or 85/90 oil. Noisy diffs can be quieted down quite a bit with EP140 or 250 oil.
BODY, PAINT AND CORROSION
Substantially better than earlier cars. Look for corrosion round the rear wheel arches, round the front and rear screens especially underneath the screen rubbers in the bottom corners, bottom of the front wings, sill closing panels and most importantly behind the front shocks on both sides. There's a reinforcing plate where the engine sub frame V mount is bolted to the body rail and some cars have corroded badly here. Corrosion around the same area may also be visible in the engine compartment on the top of the body rail around the heads of the bolts that retain the top of the V mounts. It's an MOT fail and a big welding job. Another area to check is the joint between the rear of the front inner wings and the bulkhead. Body and paintwork is otherwise pretty good however some darker coloured cars suffer from peeling lacquer. Bumper corners are susceptible to damage and bumper mounting brackets can corrode.
Lacquer on the XJ8 is soft and easy to scratch with careless washing Providing you can’t actually feel scratches with a thumbnail and the paint colour underneath is OK it’s possible to restore the bodywork to a very good finish with a through clay, polish and wax. Stripe down body flanks if car has one is hand painted and not always completely straight.
INTERIOR
Always leather with different levels of trim and seat design. Wood trim clips on and is easy to change to different type. Driver’s seat back and steering wheels tend to suffer from wear. Head linings can sag. LWB version has more room in back.
SUSPENSION, TYRES AND BRAKES
X308s are hard on suspension and brakes, listen and feel very carefully for any clonking or knocking over bumps and make sure the car comes to a straight judder-free stop under both light and hard braking. A sharp rattle heard and felt through the steering over bumps combined with a little free play in the steering wheel may be a worn crush joint on the lower steering column.
A clattery rattle from the rear is likely to be failed shocks or shock bushes. X308s with weak rear A frame bushes or rear hub pivots will tend to self steer and wander about under hard acceleration.
Feel round the tyres for uneven wear patterns; any suspension wear or bush failure giving incorrect geometry will cause tyres to feather badly and heavy wear in the inside edges is a symptom of excess negative camber from wishbone bush or ball joint failure. Slight and even feathering is normal on the front tyres.
All Jaguar XJs are very sensitive to wheel and tyre imbalances or damage, typically you'll feel a steering wobble between 50-70MPH and possibly vibration through the seat if there are any tyre problems or buckled wheels. A Hunter Roadforce wheel balance is usually the solution. Incorrect tyre pressures, worn out or cheap budget tyres will severely affect handling and ride. Most X308s exhibit a faint exhaust harmonic around 50 and another one at 65MPH. You might possibly experience a hint of driveline vibration through the body too. Don't expect too much in the way of the legendary Jaguar ride quality either - it's pretty good on touring (black shocks) suspension and 16" wheels but sport suspension cars (green shocks) are stiffer and have a thicker front anti roll bar and one on the rear too which when combined with larger diameter wheels and lower profile tyres gives a hard crashy ride on poor roads. CATS suspension may be fitted as an option to any X308. CATS has electronically controlled valves in the shocks to vary the damping rates depending on driving style. Identify CATS by the presence of a plastic cover over the top of the front shock absorber with a lead going into it.
ELECTRICIAL/ OBD2 DIAGNOSTICS
Electrical systems are generally pretty robust. As with any old car you might have the odd problem so check absolutely everything works. Even the earliest X308 is OBD2 compliant and a £20 code reader plugged into the socket in the driver’s footwell will help diagnosis a lot. Electric aerials are vunerable, there are occasional O2 sensor, airflow meter and brake light switch failures.
XJ’s need a strong battery to avoid random error messages appearing on start up. If you get one – usually TRAC FAIL – the battery is on its way out or needs several days on a trickle charge to bring it back up to full capacity.
BUYING AND LIVING WITH AN XJ
Generally the 1997-2002 XJ8 is a strong car and capable of big mileages if maintained well and not abused or neglected. It's mostly easy enough to DIY and parts are reasonable and in good supply from several independents and the Jaguar Classic Parts scheme. Expect around 26/8 MPG on the motorway, 20/4 round town and mid teens or less if you nail it everywhere. Tyres are around £100/120 a corner in 16" diameter size. The 3.2 is quick enough (0-60 is 8s) the 4.0 is much rarer and does the same in 7.0.
Shortening intervals between servicing and using a genuine fully synthetic oil is worthwhile. It’ll help protect the timing chains and give improved fuel economy. A through rust proofing and full fluid change is a benefit too if you want to preserve the car. Official servicing is annual or 10000 miles. 70k service is the expensive one on n/a cars.
One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again.
Edited by Jaguar steve on Friday 25th July 10:25
Edited by Jaguar steve on Friday 25th July 10:25
Jaguar steve said:
ZF Gearbox oil change is easy once you know how. Essential to work spotlessly clean.
Crack off gearbox sump bolts and filler plug. Drain oil and remove sump pan.
Remove filter, fit new, clean out sump pan and replace.
Initial oil fill to level of filler hole so it overflows a little.
Start engine and have assistant repeatedly cycle slowly through D N R.
Quickly pump more oil in with engine still running so it overflows from filler hole again.
With engine still running fit filler plug.
Labour for secondary timing chain tensioner swap should be 3 hours absolute max.
I wrote this buyers guide a while ago. Hopefully it'll help.
X308 OVERVIEW
To avoid XJ model confusion the 1997-2002 V8 engined XJ is referred to by its factory designation as the X308. The V8 engine in the 308 is available in a 3.2, 4.0 with VVT and a supercharged 4.0 and all versions are 5 speed auto only. £3000 should buy you a good example of a base 3.2, but the best low mileage cars or high spec ones are priced at up to double that. Engines were revised in late 1999 model year from AJ26 version to AJ27. A car fitted with the revised engine version can be identified by a VIN number ending in five, not six digits.
AJ26 cars had weak water pumps, secondary timing chain tensioners, throttle bodies and a Nicasil coating applied directly on the aluminum block bore walls rather than using conventional liners pressed into the block.
ENGINE NICASIL
Some Nicasil coatings suffered from bore erosion due to a combination of high Sulphur content fuel and repeated short trips. Sulphur maximum allowable limits in petrol were lowered considerably in Jan 2000 so any pre 2000 Nicasil coated V8 engine that's still OK now should be fine forever. Several Nicasil lined engines were changed under warranty so you may find a pre 2000 car with a later steel lined engine fitted - identify this by the presence of a green tag on the head buried at the back of the RH bank and the engine change should also be recorded in the history. Symptoms of bore erosion and loss of compression are poor cold starting, a lumpy idle and heavy oil deposits in the breather system and air intake. Crankcase pressure will be high too – a quick check for this is to slightly lift the oil filler cap at hot idle. There should be little or no internal pressure or fumes escaping. Jaguar dealers can perform a blow by check to determine engine condition. A good condition engine will show less than 25 l/m, anything over 40 l/m will make a good Top Gear coffee table.
ENGINE COOLING
Impellors on AJ26 water pumps can disintegrate giving a loss of efficiency leading to overheating and potential head gasket failure. An early pump can be changed to the later version with a metal, not plastic impeller. The temperature gauge is software driven and is not always an accurate refection of actual coolant temperature.
For an indication of water pump efficiency, remove the coolant header tank cap when the engine is STONE COLD, start up and gently increase engine speed. If the water pump is healthy you should see a steady stream of coolant into the tank from the thin return pipe that runs back from the front of the engine.
You may be able to identify the later type of pump by the presence of a black plastic, not metal gasket, but the only certain way is to remove the pump and have a look. Spring type coolant hose clips can loose tension and allow pipes to blow off and some plastic parts on the hoses, unions and thermostat housing are delicate. It’s worth replacing all the sprung coolant clips with proper Jubilee ones. Check all over for evidence of coolant leaks, particularly around the thermostat/filler cap tower and coolant (valley) pipes underneath the inlet manifold. Occasional auxiliary heater pump failures can lead to no heat output in the cabin at low engine RPM. Cycle the whole climate and a/c system through all vent operations and temperature range. Two types of coolant available for the XJ - don’t mix the later orange long life one with the earlier type.
ENGINE THROTTLE BODIES
AJ26 throttle bodies ought to have been changed to the later design under a factory safety recall. Some of the early bodies suffered from failing actuating motors causing to the engine to cut out completely on the overrun. The later design should have been factory fitted to all cars from VIN 043775 onwards.
SECONDARY TIMING CHAIN TENSIONERS AND CHAINS
The only post AJ26 revision engine issue is the secondary timing chain tensioners. These were revised to a mk 2 version around the same time as the rest of the 1999 engine revisions but the mk 2 type still had a plastic body which can crack or break up leading to slipped or broken chains. Mk 1 tensioners are actuated by engine oil pressure and failure can often be identified by a sharp rattling noise similar to a bicycle chain dragging on the chain guard on a cold start. The mk2 type is permanently tensioned by an integral spring instead which means it’ll usually fail silently.
A permanent solution is to retro-fit the later mk3 version tensioner made with a metal, not plastic body from the later 4.2 incarnation of the V8 engine and the only way to be sure of which tensioners are fitted to an 308 is to either have a receipt with tensioner part numbers C2A1511 and C2A1512 which are the metal bodied type and the required 4 new bolts to fit them on it relating to that particular car or remove the RH cam cover - the LH is a PITA to get off - and have a look. A reddish/orange (mk1) or cream (mk2) plastic tensioner body is bad news, a grey aluminum metal one (mk3) is good.
The cam phasing on the V8 means the timing gear works hard and timing chains can stretch at high mileages or on neglected cars. If this is identified then a full chain and tensioner replacement is required costing up to £1000. If the chains/sprockets and guides are OK then it’s a wise precaution to fit the mk3 secondary tensioners which is a fairly easy DIY job. Tensioners cost around £75 a set plus a couple of quid for new bolts. Cam setting tools for this job and all other special tools needed for any work on a 308 can all be hired from the Jaguar Enthusiasts’ Club. Secondary tensioners can also be changed without any tools by removing the exhaust cam whilst preserving the timing with a tie wrap holding the chain on the ex cam sprocket and easing the tensioners out of location.
Exhaust cam chains slipping one tooth – usually on a cold start - will give a very rough running engine, more than one tooth slipped means exhaust valves will meet pistons.
A good general rule of thumb for engine condition is internal cleanliness. Bright shiny metal inside the oil filler cap and dipstick along with clean oil and no evidence of leaks is a good sign, as is clear coolant that does not smell or taste bitter or acrid.
GEARBOX/ DRIVELINE
All X308s have a “sealed for life” gearbox – ZF unit in the n/a cars and a Mercedes one in the supercharged cars. Loads have failed now - just look on ebay in the non runners or spares and repairs section. Any car that hesitates or engages Drive with a jerk or thump as the engine speed rises has a potential gearbox failure looming. Gear changes should be seamless and quiet and you should be able to play tunes with the throttle, Sport switch and J gate selector. Any car stuck in 4th or 5th is FUBAR’d.
A very faint gear whine may be heard in intermediate gears. Any gearbox issues or concerns are potentially fatal. An oil and filter change may be all that’s needed to cure a gearbox malfunction but that’s never guaranteed.
Ideally the gearbox oil and filter should be changed at 50k then at 25k intervals; it's not a simple drain and refill on the ZF box as the final fill has to be done quickly with the engine running and within a narrow temperature range. There is no conventional dipstick for checking oil level.
The ZF 5 speed box on the n/a cars requires Esso/Mobil longlife LT 71141 fluid also known as Lifeguard Fluid 5 and not conventional Dexron 3. The Mercedes gearbox in the supercharged version is also sealed for life but the same change requirement apply although you can use Dexron 3 in this box and once you’ve fitted a temporary dipstick it’s a much less complex job to do. Some transmission specialists offer a flush and change service done via the rather fragile oil cooler pipes in the radiator which also gets the oil otherwise retained in the torque converter out.
The same applies to the rear axle. Oil should be changed but there’s no drain plug. Old oil has to be vacuum extracted out of the filler plug. Refill with a API GL5 75 or 85/90 oil. Noisy diffs can be quieted down quite a bit with EP140 or 250 oil.
BODY, PAINT AND CORROSION
Substantially better than earlier cars. Look for corrosion round the rear wheel arches, round the front and rear screens especially underneath the screen rubbers in the bottom corners, bottom of the front wings, sill closing panels and most importantly behind the front shocks on both sides. There's a reinforcing plate where the engine sub frame V mount is bolted to the body rail and some cars have corroded badly here. Corrosion around the same area may also be visible in the engine compartment on the top of the body rail around the heads of the bolts that retain the top of the V mounts. It's an MOT fail and a big welding job. Another area to check is the joint between the rear of the front inner wings and the bulkhead. Body and paintwork is otherwise pretty good however some darker coloured cars suffer from peeling lacquer. Bumper corners are susceptible to damage and bumper mounting brackets can corrode.
Lacquer on the XJ8 is soft and easy to scratch with careless washing Providing you can’t actually feel scratches with a thumbnail and the paint colour underneath is OK it’s possible to restore the bodywork to a very good finish with a through clay, polish and wax. Stripe down body flanks if car has one is hand painted and not always completely straight.
INTERIOR
Always leather with different levels of trim and seat design. Wood trim clips on and is easy to change to different type. Driver’s seat back and steering wheels tend to suffer from wear. Head linings can sag. LWB version has more room in back.
SUSPENSION, TYRES AND BRAKES
X308s are hard on suspension and brakes, listen and feel very carefully for any clonking or knocking over bumps and make sure the car comes to a straight judder-free stop under both light and hard braking. A sharp rattle heard and felt through the steering over bumps combined with a little free play in the steering wheel may be a worn crush joint on the lower steering column.
A clattery rattle from the rear is likely to be failed shocks or shock bushes. X308s with weak rear A frame bushes or rear hub pivots will tend to self steer and wander about under hard acceleration.
Feel round the tyres for uneven wear patterns; any suspension wear or bush failure giving incorrect geometry will cause tyres to feather badly and heavy wear in the inside edges is a symptom of excess negative camber from wishbone bush or ball joint failure. Slight and even feathering is normal on the front tyres.
All Jaguar XJs are very sensitive to wheel and tyre imbalances or damage, typically you'll feel a steering wobble between 50-70MPH and possibly vibration through the seat if there are any tyre problems or buckled wheels. A Hunter Roadforce wheel balance is usually the solution. Incorrect tyre pressures, worn out or cheap budget tyres will severely affect handling and ride. Most X308s exhibit a faint exhaust harmonic around 50 and another one at 65MPH. You might possibly experience a hint of driveline vibration through the body too. Don't expect too much in the way of the legendary Jaguar ride quality either - it's pretty good on touring (black shocks) suspension and 16" wheels but sport suspension cars (green shocks) are stiffer and have a thicker front anti roll bar and one on the rear too which when combined with larger diameter wheels and lower profile tyres gives a hard crashy ride on poor roads. CATS suspension may be fitted as an option to any X308. CATS has electronically controlled valves in the shocks to vary the damping rates depending on driving style. Identify CATS by the presence of a plastic cover over the top of the front shock absorber with a lead going into it.
ELECTRICIAL/ OBD2 DIAGNOSTICS
Electrical systems are generally pretty robust. As with any old car you might have the odd problem so check absolutely everything works. Even the earliest X308 is OBD2 compliant and a £20 code reader plugged into the socket in the driver’s footwell will help diagnosis a lot. Electric aerials are vunerable, there are occasional O2 sensor, airflow meter and brake light switch failures.
XJ’s need a strong battery to avoid random error messages appearing on start up. If you get one – usually TRAC FAIL – the battery is on its way out or needs several days on a trickle charge to bring it back up to full capacity.
BUYING AND LIVING WITH AN XJ
Generally the 1997-2002 XJ8 is a strong car and capable of big mileages if maintained well and not abused or neglected. It's mostly easy enough to DIY and parts are reasonable and in good supply from several independents and the Jaguar Classic Parts scheme. Expect around 26/8 MPG on the motorway, 20/4 round town and mid teens or less if you nail it everywhere. Tyres are around £100/120 a corner in 16" diameter size. The 3.2 is quick enough (0-60 is 8s) the 4.0 is much rarer and does the same in 7.0.
Shortening intervals between servicing and using a genuine fully synthetic oil is worthwhile. It’ll help protect the timing chains and give improved fuel economy. A through rust proofing and full fluid change is a benefit too if you want to preserve the car. Official servicing is annual or 10000 miles. 70k service is the expensive one on n/a cars.
One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again.
Cheers. Have read your buyers guide before! Just awaiting an email off the dealer to see if theres any note of these being done in the service history *thumbup*Crack off gearbox sump bolts and filler plug. Drain oil and remove sump pan.
Remove filter, fit new, clean out sump pan and replace.
Initial oil fill to level of filler hole so it overflows a little.
Start engine and have assistant repeatedly cycle slowly through D N R.
Quickly pump more oil in with engine still running so it overflows from filler hole again.
With engine still running fit filler plug.
Labour for secondary timing chain tensioner swap should be 3 hours absolute max.
I wrote this buyers guide a while ago. Hopefully it'll help.
X308 OVERVIEW
To avoid XJ model confusion the 1997-2002 V8 engined XJ is referred to by its factory designation as the X308. The V8 engine in the 308 is available in a 3.2, 4.0 with VVT and a supercharged 4.0 and all versions are 5 speed auto only. £3000 should buy you a good example of a base 3.2, but the best low mileage cars or high spec ones are priced at up to double that. Engines were revised in late 1999 model year from AJ26 version to AJ27. A car fitted with the revised engine version can be identified by a VIN number ending in five, not six digits.
AJ26 cars had weak water pumps, secondary timing chain tensioners, throttle bodies and a Nicasil coating applied directly on the aluminum block bore walls rather than using conventional liners pressed into the block.
ENGINE NICASIL
Some Nicasil coatings suffered from bore erosion due to a combination of high Sulphur content fuel and repeated short trips. Sulphur maximum allowable limits in petrol were lowered considerably in Jan 2000 so any pre 2000 Nicasil coated V8 engine that's still OK now should be fine forever. Several Nicasil lined engines were changed under warranty so you may find a pre 2000 car with a later steel lined engine fitted - identify this by the presence of a green tag on the head buried at the back of the RH bank and the engine change should also be recorded in the history. Symptoms of bore erosion and loss of compression are poor cold starting, a lumpy idle and heavy oil deposits in the breather system and air intake. Crankcase pressure will be high too – a quick check for this is to slightly lift the oil filler cap at hot idle. There should be little or no internal pressure or fumes escaping. Jaguar dealers can perform a blow by check to determine engine condition. A good condition engine will show less than 25 l/m, anything over 40 l/m will make a good Top Gear coffee table.
ENGINE COOLING
Impellors on AJ26 water pumps can disintegrate giving a loss of efficiency leading to overheating and potential head gasket failure. An early pump can be changed to the later version with a metal, not plastic impeller. The temperature gauge is software driven and is not always an accurate refection of actual coolant temperature.
For an indication of water pump efficiency, remove the coolant header tank cap when the engine is STONE COLD, start up and gently increase engine speed. If the water pump is healthy you should see a steady stream of coolant into the tank from the thin return pipe that runs back from the front of the engine.
You may be able to identify the later type of pump by the presence of a black plastic, not metal gasket, but the only certain way is to remove the pump and have a look. Spring type coolant hose clips can loose tension and allow pipes to blow off and some plastic parts on the hoses, unions and thermostat housing are delicate. It’s worth replacing all the sprung coolant clips with proper Jubilee ones. Check all over for evidence of coolant leaks, particularly around the thermostat/filler cap tower and coolant (valley) pipes underneath the inlet manifold. Occasional auxiliary heater pump failures can lead to no heat output in the cabin at low engine RPM. Cycle the whole climate and a/c system through all vent operations and temperature range. Two types of coolant available for the XJ - don’t mix the later orange long life one with the earlier type.
ENGINE THROTTLE BODIES
AJ26 throttle bodies ought to have been changed to the later design under a factory safety recall. Some of the early bodies suffered from failing actuating motors causing to the engine to cut out completely on the overrun. The later design should have been factory fitted to all cars from VIN 043775 onwards.
SECONDARY TIMING CHAIN TENSIONERS AND CHAINS
The only post AJ26 revision engine issue is the secondary timing chain tensioners. These were revised to a mk 2 version around the same time as the rest of the 1999 engine revisions but the mk 2 type still had a plastic body which can crack or break up leading to slipped or broken chains. Mk 1 tensioners are actuated by engine oil pressure and failure can often be identified by a sharp rattling noise similar to a bicycle chain dragging on the chain guard on a cold start. The mk2 type is permanently tensioned by an integral spring instead which means it’ll usually fail silently.
A permanent solution is to retro-fit the later mk3 version tensioner made with a metal, not plastic body from the later 4.2 incarnation of the V8 engine and the only way to be sure of which tensioners are fitted to an 308 is to either have a receipt with tensioner part numbers C2A1511 and C2A1512 which are the metal bodied type and the required 4 new bolts to fit them on it relating to that particular car or remove the RH cam cover - the LH is a PITA to get off - and have a look. A reddish/orange (mk1) or cream (mk2) plastic tensioner body is bad news, a grey aluminum metal one (mk3) is good.
The cam phasing on the V8 means the timing gear works hard and timing chains can stretch at high mileages or on neglected cars. If this is identified then a full chain and tensioner replacement is required costing up to £1000. If the chains/sprockets and guides are OK then it’s a wise precaution to fit the mk3 secondary tensioners which is a fairly easy DIY job. Tensioners cost around £75 a set plus a couple of quid for new bolts. Cam setting tools for this job and all other special tools needed for any work on a 308 can all be hired from the Jaguar Enthusiasts’ Club. Secondary tensioners can also be changed without any tools by removing the exhaust cam whilst preserving the timing with a tie wrap holding the chain on the ex cam sprocket and easing the tensioners out of location.
Exhaust cam chains slipping one tooth – usually on a cold start - will give a very rough running engine, more than one tooth slipped means exhaust valves will meet pistons.
A good general rule of thumb for engine condition is internal cleanliness. Bright shiny metal inside the oil filler cap and dipstick along with clean oil and no evidence of leaks is a good sign, as is clear coolant that does not smell or taste bitter or acrid.
GEARBOX/ DRIVELINE
All X308s have a “sealed for life” gearbox – ZF unit in the n/a cars and a Mercedes one in the supercharged cars. Loads have failed now - just look on ebay in the non runners or spares and repairs section. Any car that hesitates or engages Drive with a jerk or thump as the engine speed rises has a potential gearbox failure looming. Gear changes should be seamless and quiet and you should be able to play tunes with the throttle, Sport switch and J gate selector. Any car stuck in 4th or 5th is FUBAR’d.
A very faint gear whine may be heard in intermediate gears. Any gearbox issues or concerns are potentially fatal. An oil and filter change may be all that’s needed to cure a gearbox malfunction but that’s never guaranteed.
Ideally the gearbox oil and filter should be changed at 50k then at 25k intervals; it's not a simple drain and refill on the ZF box as the final fill has to be done quickly with the engine running and within a narrow temperature range. There is no conventional dipstick for checking oil level.
The ZF 5 speed box on the n/a cars requires Esso/Mobil longlife LT 71141 fluid also known as Lifeguard Fluid 5 and not conventional Dexron 3. The Mercedes gearbox in the supercharged version is also sealed for life but the same change requirement apply although you can use Dexron 3 in this box and once you’ve fitted a temporary dipstick it’s a much less complex job to do. Some transmission specialists offer a flush and change service done via the rather fragile oil cooler pipes in the radiator which also gets the oil otherwise retained in the torque converter out.
The same applies to the rear axle. Oil should be changed but there’s no drain plug. Old oil has to be vacuum extracted out of the filler plug. Refill with a API GL5 75 or 85/90 oil. Noisy diffs can be quieted down quite a bit with EP140 or 250 oil.
BODY, PAINT AND CORROSION
Substantially better than earlier cars. Look for corrosion round the rear wheel arches, round the front and rear screens especially underneath the screen rubbers in the bottom corners, bottom of the front wings, sill closing panels and most importantly behind the front shocks on both sides. There's a reinforcing plate where the engine sub frame V mount is bolted to the body rail and some cars have corroded badly here. Corrosion around the same area may also be visible in the engine compartment on the top of the body rail around the heads of the bolts that retain the top of the V mounts. It's an MOT fail and a big welding job. Another area to check is the joint between the rear of the front inner wings and the bulkhead. Body and paintwork is otherwise pretty good however some darker coloured cars suffer from peeling lacquer. Bumper corners are susceptible to damage and bumper mounting brackets can corrode.
Lacquer on the XJ8 is soft and easy to scratch with careless washing Providing you can’t actually feel scratches with a thumbnail and the paint colour underneath is OK it’s possible to restore the bodywork to a very good finish with a through clay, polish and wax. Stripe down body flanks if car has one is hand painted and not always completely straight.
INTERIOR
Always leather with different levels of trim and seat design. Wood trim clips on and is easy to change to different type. Driver’s seat back and steering wheels tend to suffer from wear. Head linings can sag. LWB version has more room in back.
SUSPENSION, TYRES AND BRAKES
X308s are hard on suspension and brakes, listen and feel very carefully for any clonking or knocking over bumps and make sure the car comes to a straight judder-free stop under both light and hard braking. A sharp rattle heard and felt through the steering over bumps combined with a little free play in the steering wheel may be a worn crush joint on the lower steering column.
A clattery rattle from the rear is likely to be failed shocks or shock bushes. X308s with weak rear A frame bushes or rear hub pivots will tend to self steer and wander about under hard acceleration.
Feel round the tyres for uneven wear patterns; any suspension wear or bush failure giving incorrect geometry will cause tyres to feather badly and heavy wear in the inside edges is a symptom of excess negative camber from wishbone bush or ball joint failure. Slight and even feathering is normal on the front tyres.
All Jaguar XJs are very sensitive to wheel and tyre imbalances or damage, typically you'll feel a steering wobble between 50-70MPH and possibly vibration through the seat if there are any tyre problems or buckled wheels. A Hunter Roadforce wheel balance is usually the solution. Incorrect tyre pressures, worn out or cheap budget tyres will severely affect handling and ride. Most X308s exhibit a faint exhaust harmonic around 50 and another one at 65MPH. You might possibly experience a hint of driveline vibration through the body too. Don't expect too much in the way of the legendary Jaguar ride quality either - it's pretty good on touring (black shocks) suspension and 16" wheels but sport suspension cars (green shocks) are stiffer and have a thicker front anti roll bar and one on the rear too which when combined with larger diameter wheels and lower profile tyres gives a hard crashy ride on poor roads. CATS suspension may be fitted as an option to any X308. CATS has electronically controlled valves in the shocks to vary the damping rates depending on driving style. Identify CATS by the presence of a plastic cover over the top of the front shock absorber with a lead going into it.
ELECTRICIAL/ OBD2 DIAGNOSTICS
Electrical systems are generally pretty robust. As with any old car you might have the odd problem so check absolutely everything works. Even the earliest X308 is OBD2 compliant and a £20 code reader plugged into the socket in the driver’s footwell will help diagnosis a lot. Electric aerials are vunerable, there are occasional O2 sensor, airflow meter and brake light switch failures.
XJ’s need a strong battery to avoid random error messages appearing on start up. If you get one – usually TRAC FAIL – the battery is on its way out or needs several days on a trickle charge to bring it back up to full capacity.
BUYING AND LIVING WITH AN XJ
Generally the 1997-2002 XJ8 is a strong car and capable of big mileages if maintained well and not abused or neglected. It's mostly easy enough to DIY and parts are reasonable and in good supply from several independents and the Jaguar Classic Parts scheme. Expect around 26/8 MPG on the motorway, 20/4 round town and mid teens or less if you nail it everywhere. Tyres are around £100/120 a corner in 16" diameter size. The 3.2 is quick enough (0-60 is 8s) the 4.0 is much rarer and does the same in 7.0.
Shortening intervals between servicing and using a genuine fully synthetic oil is worthwhile. It’ll help protect the timing chains and give improved fuel economy. A through rust proofing and full fluid change is a benefit too if you want to preserve the car. Official servicing is annual or 10000 miles. 70k service is the expensive one on n/a cars.
One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again.
Edited by Jaguar steve on Friday 25th July 10:25
Edited by Jaguar steve on Friday 25th July 10:25
Hi Steve, fantastic piece of information. Just bought my stunning 2002 XJ 3.2 sport last week, owned by a wonderful for 9 years and immaculately well looked after, 67k miles.
Just a couple of questions:
1. Not clear on this bit: "One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again." Is there any specific software fault you are referring to?
2. My car drives well, only thing is I noticed that when I am driving at around 70 miles plus and need to apply the brakes, the steering wheel vibrates/wobbles very slightly. How should this be addressed? Car has been regularly serviced, and was serviced only a couple of weeks back, rest is all swell. Cheers
Just a couple of questions:
1. Not clear on this bit: "One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again." Is there any specific software fault you are referring to?
2. My car drives well, only thing is I noticed that when I am driving at around 70 miles plus and need to apply the brakes, the steering wheel vibrates/wobbles very slightly. How should this be addressed? Car has been regularly serviced, and was serviced only a couple of weeks back, rest is all swell. Cheers
suneernoronha said:
Hi Steve, fantastic piece of information. Just bought my stunning 2002 XJ 3.2 sport last week, owned by a wonderful for 9 years and immaculately well looked after, 67k miles.
Just a couple of questions:
1. Not clear on this bit: "One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again." Is there any specific software fault you are referring to?
2. My car drives well, only thing is I noticed that when I am driving at around 70 miles plus and need to apply the brakes, the steering wheel vibrates/wobbles very slightly. How should this be addressed? Car has been regularly serviced, and was serviced only a couple of weeks back, rest is all swell. Cheers
No idea if over fuel fault can be fixedJust a couple of questions:
1. Not clear on this bit: "One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again." Is there any specific software fault you are referring to?
2. My car drives well, only thing is I noticed that when I am driving at around 70 miles plus and need to apply the brakes, the steering wheel vibrates/wobbles very slightly. How should this be addressed? Car has been regularly serviced, and was serviced only a couple of weeks back, rest is all swell. Cheers
Doesn't always happen and when it does is in varying degrees. Best to avoid the risk though as not good for starter motor as a bad case will cause severe loss of compression and it'll take several minutes of continuous cranking to restore enough compression for the engine to fire.
Steering wheel wobble under braking sounds like front discs may be slightly warped. It's fairly common on XJs Suggest you check all front suspension bushes and components and if all ok then change discs and pads. Cheap pattern discs don't last well - treat the car to genuine OE ones.
suneernoronha said:
Hi Steve, fantastic piece of information. Just bought my stunning 2002 XJ 3.2 sport last week, owned by a wonderful for 9 years and immaculately well looked after, 67k miles.
Just a couple of questions:
1. Not clear on this bit: "One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again." Is there any specific software fault you are referring to?
2. My car drives well, only thing is I noticed that when I am driving at around 70 miles plus and need to apply the brakes, the steering wheel vibrates/wobbles very slightly. How should this be addressed? Car has been regularly serviced, and was serviced only a couple of weeks back, rest is all swell. Cheers
No idea if over fuel fault can be fixedJust a couple of questions:
1. Not clear on this bit: "One last thing. A software fault means you should never start an XJ8 from cold and then switch off again straight away and before allowing the temp gauge to move off the cold section of the scale. Chances are it’ll flood when you next start and wash all the oil of the bores and it’s a right PITA to get it running again." Is there any specific software fault you are referring to?
2. My car drives well, only thing is I noticed that when I am driving at around 70 miles plus and need to apply the brakes, the steering wheel vibrates/wobbles very slightly. How should this be addressed? Car has been regularly serviced, and was serviced only a couple of weeks back, rest is all swell. Cheers
Doesn't always happen and when it does is in varying degrees. Best to avoid the risk though as not good for starter motor as a bad case will cause severe loss of compression and it'll take several minutes of continuous cranking to restore enough compression for the engine to fire.
Steering wheel wobble under braking sounds like front discs may be slightly warped. It's fairly common on XJs Suggest you check all front suspension bushes and components and if all ok then change discs and pads. Cheap pattern discs don't last well - treat the car to genuine OE ones.
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