Think I’ve heard the V8 “Death Rattle”

Think I’ve heard the V8 “Death Rattle”

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freqeist1

9 posts

93 months

Thursday 17th November 2016
quotequote all
Bloody hell, I was thinking of buying a Jag off of Ebay, looks good but the way he briefly mentions the timing tensioners, thankfully I read this thread


eBay item number:
142178178522

Jaguar steve

9,232 posts

210 months

Thursday 17th November 2016
quotequote all
The only design of tensioners that usually allow start up chain rattle are the first gen red ones that were actuated by oil pressure. Jaguar revised the design on the second gen ones and incorporated a spring to keep the secondary chain taut all the time. Both can fail catastrophically but the second gen one will often do so silently.

Easy enough to change the secondary tensioners alone. All you need are a few small sockets, a couple of tie wraps and a wedge cut from some scrap wood. If all the timing chains and slippers and tensioners are worn and stretched or damaged then the whole lot will need doing and that's a much, much bigger task requiring something in the region of a days competent labour and timing tools and pullers as well as a few hundred quids worth of chain kit and gaskets.

JS X308 Buyers Guide

OVERVIEW

To avoid model confusion between the XJ8 models the 1997-2002 V8 engined XJ8 can be referred to by its factory designation as the X308. The all new at the time V8 engine in the 308 has similar architecture to current cars and is available in a 3.2, 4.0 with VVT and a supercharged 4.0 and all versions are 5 speed auto only.
Engines were revised in the late 1999 model year from the original 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 engines suffered weak water pumps, secondary timing chain tensioner and throttle body failures and had a Nicasil coating applied directly on the cylinder bore walls rather than using conventional steel liners pressed into the block.
ENGINE NICASIL
Some Nicasil coatings eroded 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 engine that you know for sure is OK now should not be any concern. Several Nicasil 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 erosion and loss of compression are fast cranking, 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 undo and 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 20l/m anything over 30 l/m is shagged.
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. It will tell you if your engine is cold, hot, or knackered - that's all. There is a conversion kit from the States that converts the gauge to give a accurate reading.
For an indication of water pump efficiency, remove the coolant header tank cap when the engine is absolutely stone cold, start up and gently increase engine speed. If the water pump is healthy you should see a strong stream of coolant into the tank from the thin black pipe that runs from the top left of the radiator to the header tank.
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 let pipes blow off and some plastic parts on the hoses, unions and thermostat housing are very delicate. Check all over the engine compartment for evidence of coolant leaks, particularly around the thermostat/filler cap tower and coolant (valley) pipes underneath the inlet manifold as well as around the expansion tank hidden under the front of the nearside wing. Leave the engine idling to make sure the cooling fans kick in. Sniff around too as hot coolant has a distinctive smell. Auxiliary heater pump failures cause loss of heat output in the cabin at low engine RPM. Two types of coolant available for the XJ8 - don’t mix the later orange long life one with the earlier green one.
ENGINE THROTTLE BODIES
AJ26 throttle bodies all 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 a high speed 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 that remains is the secondary timing chain tensioners. These were replaced by a mk 2 version in Oct 1998 from engine no 98102106XX 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. Jaguar issued a TSB in 2005 advising the fitment of these to the X308. 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 shorter 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 places uneven loading on the timing chains and they 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 and sprockets and guides are servicable then it’s a sensible move 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. Camshaft setting tools can be hired from the Jaguar Enthusiasts’ Club. Secondary tensioners can also be changed without any setting tools by tie wrapping the secondary chain to the exhaust cam sprocket and jamming the chain on the inlet cam sprocket with a wedge of wood to preserve the timing and removing the exhaust cam alltogether. Taking the cam out gives just enough room to ease the secondary tensioner away from position and fit a replacement. 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 contact pistons.
A good general rule of thumb for engine condition is quiet running with just faint injector tick audible and 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
X308 gearboxes were marketed as “sealed for life” meaning no oil changes are called for in the schedule to reduce servicing costs. It's a ZF unit in the n/a cars and a Mercedes one in the supercharged cars. Any hesitation or engagement of Drive with a jerk as the engine speed rises means a potential gearbox failure looming and any gearbox stuck in 4th or 5th or only driving in reverse is beyond saving. A very faint gear whine may be heard in intermediate gears but any gearbox issues or concerns are potentially fatal. An oil and filter change might be all that’s needed to cure a gearbox malfunction like occasional reluctant or rough changes but that’s never guaranteed. Gear changes should be seamless and quiet and you should have instant response using the throttle, Sport switch and J gate selector.
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 standard Dexron 3 in this box and once you have 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 most of the oil otherwise retained in the torque converter out.
The same sealed for life marketing applies to the rear axle. Oil ought be changed but there’s no drain plug so old oil has to be vacuum extracted out of the filler plug. Refill with a API GL5 75 or 85/90 oil. Whiny diffs - a high mileage Jaguar speciality feature - can be quieted down considerably with EP140 or even EP250 oil.

BODY, PAINT AND CORROSION
Substantially better than earlier Jaguars. But 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, jacking points and most importantly on the inner wing 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 two 10mm bolts that retain the top of the V mounts. Corrosion here is an MOT fail and a big welding job if the subframe has to be dropped. 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. Darker cars often appear to have slight but consistent orange peel in the lacquer all over the body too but you can use this to spot inconsistencies and start thinking about accident damage repairs. 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 glossy finish with a mornings detailing if that's your thing. Stripe down body flanks if car has one is hand painted and not always completely straight.
INTERIOR
Very cozy given the size of the car. Always leather with different levels of trim and seating style. Wood trim clips on and is easy to change to different design. Driver’s seat back and steering wheels tend to suffer from wear. Head linings can sag. LWB version has extra room in the back. Check everything and repeatedly cycle the whole climate and a/c system through all vent operations and temperature range and run the interior fans at high speed while doing so and listen for vibration. Foam can get dislodged from the flaps and jam in the fans.

SUSPENSION, TYRES AND BRAKES
X308s are heavy and can be 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. Stop the car on the handbrake to make sure it works. 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 shock bushes. A soft clonk from the front might just be anti roll bar bushes. X308s with weak rear A frame bushes or worn rear hub pivots will tend to self steer and wander about under hard acceleration.
Look and feel round the tyres for uneven wear patterns; any suspension wear or bush failure allowing incorrect geometry will cause tyres to feather badly and excessive wear in the inside edges of the fronts is sometimes a symptom of excess negative camber from wishbone bush or ball joint failure rather than excess toe out. There is a subtle bifference in the two wear patterns with excess toe out usually causing a even slope across the tyre and excess camber more likley to show a sudden step up in wear on the inside 25%. Slight and even feathering inside and out is normal on the front tyres.
308s 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 from anything over 45MPH if there are any tyre problems or buckled wheels. A Hunter Roadforce wheel balance may help diagnosis. Incorrect tyre pressures and knackered or faulty tyres will severely influence 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 acceptable on touring (black shocks) suspension and 16" wheels but sport suspension cars (green shocks) have higher damping rates and have a thicker front anti roll bar and one fitted 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. 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 easy to damage but easy to replace, there are occasional O2 sensor, airflow meter and brake light switch failures. Non working key fobs usually need nothing more than new batteries, a clean and easy DIY reprogramme. 308'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 car for a competent DIYer to work on and parts are pretty reasonable and in good supply from several independents and the Jaguar Classic Parts scheme. The few specialist tools required can be hired from the JEC.
Expect around 26/8 MPG on the motorway or touring, between 20 and 24 around town and mid teens or less if you're nailing it in a n/a car, the supercharged versions typically use more. Quality tyres start around £100 a corner in 16" diameter size. Early cars fall into a cheaper VED bracket then later ones. Servicing schedule is annual or 10000 miles. 70k service is the expensive one on n/a cars
3.2 does 0-60 in 8.1s and the 4.0 is a second quicker.
Shortening intervals between servicing and using a genuine fully synthetic oil is worthwhile IMO. It’ll help protect the timing chains and give a small improvement in fuel economy. Keeping oil topped up to the maximum mark - both my V8's have used a little - is a plan too as it reduces stress on the oil and both reduces the possibility of oil starvation on rapid cornering and seems somehow to make a subtle improvement in refinement. A through rust proofing and full fluid change is a benefit too if you want to preserve the car. Waxoil has the effect of lubricating suspension components and a good soaking - not anywhere near the brakes 'tho please - will subtly improve the ride quality.
Keeping the inside of the throttle body and the elements of the airflow meter spotlessly clean as well as the 2.5mm calibrated bleed hole in the breather system will stabilize and improve throttle response and consistency especially at small openings. Again it's a subtle but worthwhile improvement. Any leaks in the air intake or breather system need fixing.
Providing the suspension components are all OK and the tyres are reasonable a occasional Hunter full 4 wheel laser alignment geometry check and reset will improve feel of the car dramatically. Small changes in tyre pressure have a unusually big influence on how the car drives too.
One last thing. A software error means its a very bad thing to start an X308 from cold and then switch off again straightaway or before allowing the temp gauge to move off the cold section of the scale. There's a chance 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.


P700DEE

1,111 posts

230 months

Thursday 17th November 2016
quotequote all
Hi Steve, I raised the question on the xkec and wondered about your experience. Of the chain/tensioner failures how often is this actually "catastrophic"? I have seen loads of "almost" pics of cracked tensioners, a number of posts regarding death rattles and missfires that have been due to failures. How many actual failures that did result in valve damage? Whilst tensioners are an issue it is not unique to Jaguar and as a word of warning just look to the XKF post where the chain has stretched and the valves have impacted and this on a 5.0 engine with the latest chains and tensioners! I would always advocate that if you want to keep your V8 jag long term get the tensioners done and this includes routine replacement of the later generation after 10+years or 100K+ miles

Jaguar steve

9,232 posts

210 months

Thursday 17th November 2016
quotequote all
P700DEE said:
Hi Steve, I raised the question on the xkec and wondered about your experience. Of the chain/tensioner failures how often is this actually "catastrophic"? I have seen loads of "almost" pics of cracked tensioners, a number of posts regarding death rattles and missfires that have been due to failures. How many actual failures that did result in valve damage? Whilst tensioners are an issue it is not unique to Jaguar and as a word of warning just look to the XKF post where the chain has stretched and the valves have impacted and this on a 5.0 engine with the latest chains and tensioners! I would always advocate that if you want to keep your V8 jag long term get the tensioners done and this includes routine replacement of the later generation after 10+years or 100K+ miles
My actual practical experience is changing two sets of tensioners. Both 2nd gen types and both at modest mileages, something like 60 and 45k IIRC and both had evidence of cracking along the length of the body. One of the 4 had cracked sufficiently for the piston to fall out when removed from the engine. The only thing preventing that happening in service was the remaining tension in the chain.

As far as I can surmise from reading round the subject and sucking the JEC technical resources and Jaguar TSB's as well as other forums and magazine articles is the first gen types present two failure mechanisms. First is delamination of the slipper the chain runs on allowing the chain become slack and run on the top of the tensioner piston instead - hence the rattle - and second is the body cracks and allows the piston to both loose force on the chain due to loss of oil pressure and be pulled sideways by the shear forces of the moving chain.

As far as I can see the second gen types are not known for loosing the slippers but they still crack and disintegrate.

The chain can jam on the ineffective tensioner and either jump teeth or snap all together. One tooth mistiming is enough to cause serious exhaust cam retardation and rough running and anymore than one tooth means valves and pistons contact. I think the latter can be reasonably described as catastrophic. smile

Have a look in the spares and repairs section on ebay. Timing gear is a very common failure - along with lunched autoboxes - in earlier V8 engined Jaguars. I think it's reasonable to believe given the evidence that a car that's had regular oil changes and is fitted with third gen tensioners and has no history of overheating should not present any problems 'tho but nonetheless whipping the cam cover off and having a long hard look at all the timing gear is invaluable.

melhookv12

958 posts

174 months

Saturday 19th November 2016
quotequote all
I've seen 2.
One xkr and one 3.2.
The xkr wrecked the engine the 3.2 rattled and ran rough but the owner was lucky as I just did the top tensioners.

My dad has an xkr I did the chains and tensioners under warranty many Moons ago. 2nd generation. He told me he had heard a strange noise so I have just replaced all chains and tensioners with latest type. Parts were around £330.
There were tiny signs of cracking on the top tensioners and cracking on the primary guides. His car hasn't done any great milage but I told him if they go bang I'm not fixing it !!!