could anyone help with potential XK8 Purchase?
Discussion
Looking at getting a 97/98 XK8 so looking at the low end of the market with around 80k-110k on the clock.
I know the engines are the Nikasil ones and I've been told and looked through here using the search that if it's lasted this long it's likely to have either been sorted or if on original then it's likely to be fine so not too concerned about those issues.
However, More concerned about the timing belt tensioners. If I buy one that hasn't had replacments or no history to prove etc is it best to change these as a preventative mearsure and if so how much roughly does it cost to do?
Are there any other issues I need to be looking at before I go off to hunt one down?
Thanks.
I know the engines are the Nikasil ones and I've been told and looked through here using the search that if it's lasted this long it's likely to have either been sorted or if on original then it's likely to be fine so not too concerned about those issues.
However, More concerned about the timing belt tensioners. If I buy one that hasn't had replacments or no history to prove etc is it best to change these as a preventative mearsure and if so how much roughly does it cost to do?
Are there any other issues I need to be looking at before I go off to hunt one down?
Thanks.
Brain engaged now....
Secondary timing chain tensioners will at this age of car, unless they have been changed already, be the first generation ones.
This is not good news. Even some of the second generation tensioners have been reported as failing
Sone of the independents will agree to change just the secondary tensioners at a cost of around £300/£400 others insist on changing the primary and secondary chains and all the tensioners and guides. Cost for this will be over £1000.
Make sure the third generation metal-bodied tensioners are fitted
Complete chain kits are about £300. If you're mecanically skilled, (it's not really a weekend mechanic's job IMO), it's possible to hire all the special tools you need from the JEC for about £70 a week and do the job yourself. Allow a couple of days and get hold of a good torque wrench with a range up to 300ft/lb
Secondary timing chain tensioners will at this age of car, unless they have been changed already, be the first generation ones.
This is not good news. Even some of the second generation tensioners have been reported as failing
Sone of the independents will agree to change just the secondary tensioners at a cost of around £300/£400 others insist on changing the primary and secondary chains and all the tensioners and guides. Cost for this will be over £1000.
Make sure the third generation metal-bodied tensioners are fitted
Complete chain kits are about £300. If you're mecanically skilled, (it's not really a weekend mechanic's job IMO), it's possible to hire all the special tools you need from the JEC for about £70 a week and do the job yourself. Allow a couple of days and get hold of a good torque wrench with a range up to 300ft/lb
Check it out at http://www.pistonheads.com/gassing/topic.asp?h=0&a...
But yes, make checking the Tensioners you first job or it could be very expensive.
I would recommend a vehicle inspection and get the vehicle to a Jag dealers to have a Blow-by test done which is a quick/cheap way of checking how good an old Nikasil engine is. It will give you a reading, whereby 0 to 40 is technically a pass. However there are plenty of cars around, so be choosey and consider walking away from cars with a reading of 20 or more.
Check the condition of bushes as XK's are heavy on their suspension parts. Check the condition of the tyres for uneven wear, as they need to be aligned properly, and may indicate worn bushes if not.
Check the windows drop a little as you open the door, and go up after you close it... if not the car may have been stood for a while and the battery is on the way out. XK's are very sensitive to drops in electrical power.
When you drive it make sure you you check the whole range of the 'J'-gate gearbox, including the 'manual' positions. Also test the 'Sport' button just below the gear selector - Red light on = higher rev gear changes, less hunting of gears in town/low throttle mode ( + loads more fun
)
Obviously this is in addition to the normal car-buying checks..... good hunting
Rgds
Simon
But yes, make checking the Tensioners you first job or it could be very expensive.
I would recommend a vehicle inspection and get the vehicle to a Jag dealers to have a Blow-by test done which is a quick/cheap way of checking how good an old Nikasil engine is. It will give you a reading, whereby 0 to 40 is technically a pass. However there are plenty of cars around, so be choosey and consider walking away from cars with a reading of 20 or more.
Check the condition of bushes as XK's are heavy on their suspension parts. Check the condition of the tyres for uneven wear, as they need to be aligned properly, and may indicate worn bushes if not.
Check the windows drop a little as you open the door, and go up after you close it... if not the car may have been stood for a while and the battery is on the way out. XK's are very sensitive to drops in electrical power.
When you drive it make sure you you check the whole range of the 'J'-gate gearbox, including the 'manual' positions. Also test the 'Sport' button just below the gear selector - Red light on = higher rev gear changes, less hunting of gears in town/low throttle mode ( + loads more fun
)Obviously this is in addition to the normal car-buying checks..... good hunting
Rgds
Simon
Many thanks for that!
I'm looking at a car today which does seem very good value. It has a full service history but not all the receipts are present so I wanted to factor in the cost of changing the tensioners as I would rather spend the extra money on it when I buy it than hope it doesn't break!
Is there any way of checking by looking? Sorry I have no idea as I'm not massively mechanically minded!
Thanks
I'm looking at a car today which does seem very good value. It has a full service history but not all the receipts are present so I wanted to factor in the cost of changing the tensioners as I would rather spend the extra money on it when I buy it than hope it doesn't break!
Is there any way of checking by looking? Sorry I have no idea as I'm not massively mechanically minded!
Thanks
No not really Paul, as they are not visible. They are inside the top rocker covers at the front of the engine, so those would need to come off for you to see them.
Listen for a very metallic clackerty sound on cold start up. That's an idication they are shot. but it's not a fool-proof way. Mine were silent but on checking they were completely shot!
Tell the seller not to warm the engine before you get there
Edited to add a picture of mine. You can see how the poly-slipper thing has worn down right to the metal shoe. The Tensioner Bodies were also cracked.
Listen for a very metallic clackerty sound on cold start up. That's an idication they are shot. but it's not a fool-proof way. Mine were silent but on checking they were completely shot!
Tell the seller not to warm the engine before you get there Edited to add a picture of mine. You can see how the poly-slipper thing has worn down right to the metal shoe. The Tensioner Bodies were also cracked.
Edited by robocop on Monday 10th December 10:19
Jaguar steve said:
Jeeeez, just look at the slack in that secondary chain 
Do you mean the vertical 'Primary' chain Steve? I guess thats why it has long guides either side...which also crack with the Tensioner bodies 
If you do still mean the secondary, when the new ones were fitted they push up under spring loading too...so the chain is not tight even when new.
and the Secondary Tensioners close up
and with it all done (New Secondary Tensioners, Chains and Guides) .. PHEW!
Edited by robocop on Monday 10th December 18:19
CLUNK OF BRAIN ENGAGING AFTER POSTING No, I meant to type secondary chain tensioner. Doh!
I don't think I have ever seen one extended that far before.
Intresting pics though, your engine looks quite dirty inside which seems to be a pretty common sight when looking at failed tensioners. I wonder how much extending the service intervals to 10k and running on oil with a build up of comtaminants and failing additives has to do with tensioner bodies becoming brittle and failing?
Well it is 11yrs old this week and has done 93,000mls. I have had it for 4.5 years and have used nothing but Castrol 5W-30 and done two oil changes a year. Also used Shell Optimax for the entire time. The Blow-by reading when I bought it was 15 and I had it done last week and it was 10 (was 10 last year too). The pictures were taken last year.
So if it is dirty ..... it's not my fault
I look after it better than I do my wife 
So if it is dirty ..... it's not my fault
I look after it better than I do my wife robocop said:
Well it is 11yrs old this week and has done 93,000mls. I have had it for 4.5 years and have used nothing but Castrol 5W-30 and done two oil changes a year. Also used Shell Optimax for the entire time. The Blow-by reading when I bought it was 15 and I had it done last week and it was 10 (was 10 last year too). The pictures were taken last year.
So if it is dirty ..... it's not my fault I look after it better than I do my wife
Sure you do...I was commenting the build up of brown deposits over the engine components seems to be a common factor in failure of plastic and PTFE components, not just in Jaguar engines. I've experienced similar problems with Renault timing chains years ago and in the Vauxhall OHC engines, when the service intervals were extended.So if it is dirty ..... it's not my fault
I look after it better than I do my wife If the detergent package in the oil is doing its job properly, and is not depleted either by infrequent changes, operating conditions or poor quality fuel then combustion deposits should remain suspended in the oil and not all over the engine - resulting in filthy oil and a relatively clean engine.
I'm sure Jaguar, and most other manufacturers have done nobody any favours by extending service intervals, and unfortunately once these deposits have baked on they are hard to shift.
With you now Steve. I guess if the previous owner had done an extra oil change each year it would not be as bad. Maybe they even used a thicker mineral oil instead of the recommended synthetic 5W-30...who knows. You can see in a couple of places the build up has started to lift, so I will stick with the 5W-30 changed twice a year.
Regarding the comment on the secondary chain. The picture is of the N/S bank which has the bottom part of the chain taught and the tensioner working on the top, and for the O/S bank it is the other way round so the top looks taught as it is 'driving' the rotation. I think that's right
Regarding the comment on the secondary chain. The picture is of the N/S bank which has the bottom part of the chain taught and the tensioner working on the top, and for the O/S bank it is the other way round so the top looks taught as it is 'driving' the rotation. I think that's right
ParanoidAndroid said:
Hi guys,
What sort of age/mileage should these be checked and if required replaced? Are they checked by Jaguar at each service?
Graham
Hello Graham What sort of age/mileage should these be checked and if required replaced? Are they checked by Jaguar at each service?
Graham
No Jaguar don't really check them as routine. Yours is a 02 4.2 XKR, yes? I think you may have the second generation that came out for a while, before they settled on the current third metal-bodied design. Only real way is to take the cam covers off and have a butchers
Rgds
Simon
Edited to add that the 3rd Generation Tensioners came out in spring 2005 so you probably have the second type...worth getting them inspected IMO, just in case.
Edited by robocop on Tuesday 11th December 18:08
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