Help needed - Did Compression test today
Hi Folks.
Got the 98 XJR that I have been looking at inspected by a mechanic today, and was pretty happy with what I found. For the most part, the car is in great shape. Came up with a couple of issues:
Ball joints - One ball joint is definitely weak, and they other is showing some wear. Basically need to fix both. Bummer is that all I can find around here is the whole control arm assembly.
Tensioners - Finally got a chance to give it a cold start, and for the first few seconds I got a pretty nasty sounding rattle. Then it died down almost immediately, and stayed nice and quiet thereafter. Definitely needs to be done. Was prepared for this one (thanks JagaurForums!). Just need to decide if I should do the primary and secondary tensioners, or just the secondary. Probably worthwhile doing the water pump while we are in there.
Compression test - Had the mechanic do a compression test, and I got the following results:
Left Bank Right Bank
115 115
120 119
120 120
125 125
Surprisingly consistent, side to side. The spread between them is good, but I don't know what kind of numbers I should be looking for. Is the 120 area decent compression for a 70,000 mile, XJR engine?
If anyone can check these for me, I would really appreciate it!
Thanks
Erik
Got the 98 XJR that I have been looking at inspected by a mechanic today, and was pretty happy with what I found. For the most part, the car is in great shape. Came up with a couple of issues:
Ball joints - One ball joint is definitely weak, and they other is showing some wear. Basically need to fix both. Bummer is that all I can find around here is the whole control arm assembly.
Tensioners - Finally got a chance to give it a cold start, and for the first few seconds I got a pretty nasty sounding rattle. Then it died down almost immediately, and stayed nice and quiet thereafter. Definitely needs to be done. Was prepared for this one (thanks JagaurForums!). Just need to decide if I should do the primary and secondary tensioners, or just the secondary. Probably worthwhile doing the water pump while we are in there.
Compression test - Had the mechanic do a compression test, and I got the following results:
Left Bank Right Bank
115 115
120 119
120 120
125 125
Surprisingly consistent, side to side. The spread between them is good, but I don't know what kind of numbers I should be looking for. Is the 120 area decent compression for a 70,000 mile, XJR engine?
If anyone can check these for me, I would really appreciate it!
Thanks
Erik
the compression is good, change the oil every 3k and use engine restore to help maintain ring seal with every oil change. dont chance the tensioners. pull the covers and inspect. if theyre plastic bodied, change them no matter what they look like. if you break 1 your engine will cost more to replace than the car is worth. DO NOT gamble with tensioners
The compression is a little low. Should be in the 150 psi range (new). The fact that they are consistent is great. BRUTAL provides the solution to the compression issue.
If you can hear the rattle I would not even crank it again. One tooth, run rough, two teeth, run badly, three teeth, bend valves.
Welcome to the wonderful world of Jaguar!
If you can hear the rattle I would not even crank it again. One tooth, run rough, two teeth, run badly, three teeth, bend valves.
Welcome to the wonderful world of Jaguar!
Hi Brutal.
Thanks so much for your input.
My plan is that should we come to an agreement on price, I will immediately get the tensioners done. Like right away! Not gonna worry about inspecting them, just get them done. Should I do both the primary and secondary tensioners, or just concentrate on the secondary ones? Does it make sense to do the water pump at the same time?
When you say "engine restore", are you thinking of any particular product?
Thanks!
Erik
Thanks so much for your input.
My plan is that should we come to an agreement on price, I will immediately get the tensioners done. Like right away! Not gonna worry about inspecting them, just get them done. Should I do both the primary and secondary tensioners, or just concentrate on the secondary ones? Does it make sense to do the water pump at the same time?
When you say "engine restore", are you thinking of any particular product?
Thanks!
Erik
yes its called engine restore and is about $10, I have gotten excellant result in engines to balance and increase compression.and no you really only need to worry about the secondary(upper tensioners). water pump wouldnt hurt unless theve had it done since that was the range for impeller implosion until they changed the composit. look for other issues like bushings, upper shock mounts, sway bar bushings and wheel bearings. these are all things that should be checked as these should be figured into price if theyre needing to be replaced. replace them thermostat too is you do the pump and take off the check ball from the thermostat.
yes its called engine restore and is about $10, I have gotten excellant result in engines to balance and increase compression.and no you really only need to worry about the secondary(upper tensioners). water pump wouldnt hurt unless theve had it done since that was the range for impeller implosion until they changed the composit. look for other issues like bushings, upper shock mounts, sway bar bushings and wheel bearings. these are all things that should be checked as these should be figured into price if theyre needing to be replaced. replace them thermostat too is you do the pump and take off the check ball from the thermostat.
Thanks again! Appreciate your thoughts.
Spent about an hour under it today on a hoist, and except for the rear sway bar links, everything looked good. Front bearing had just been done. Shocks looked recent; very clean (who makes a green strut for Jags anyway?). Brakes are all good.
Check ball out of the thermostat, huh? Will keep that in mind.
For engine restore, do you mean this:

Never was a big believer in additives. Always a synthetic oil kind of guy. But it is worth keeping in mind.
Very happy with what I saw under the car. It has been well looked after!
Thanks again
Erik
The compression is a little low. Should be in the 150 psi range (new). The fact that they are consistent is great. BRUTAL provides the solution to the compression issue.
If you can hear the rattle I would not even crank it again. One tooth, run rough, two teeth, run badly, three teeth, bend valves.
Welcome to the wonderful world of Jaguar!
If you can hear the rattle I would not even crank it again. One tooth, run rough, two teeth, run badly, three teeth, bend valves.
Welcome to the wonderful world of Jaguar!
Sorry, I missed your post before. You must have posted just between when I started to write, and the long delay in actually posting.
Another believer in engine restore, huh? Interesting. Would have never considered trying it without you guys recommending it.
So the compression is a little low? A little low compared to new? Compared to where it should be age wise (70,000 miles)? Anything worthy of concern in your opinion there?
Yeah, gotta get the tensioner thing done ASAP. Scary stuff!
Thanks
Erik
Trending Topics
The primary chain tensioner (on the bottom chain), is not so critical, certainly it is the top ones that cause all the damage, due to the peculiar nature of the loads a V8 engine puts on these little chains. What does go, apparently are the chain slippers and guides - they crack up, so if you really want peace of mind, do the lot !!
120 is decent for the age/mileage and its fairly even. Off course it also deepnds on how he did the test, was it both wet and dry to check the true sealing of the rings or valves. And did he have the throttle blocked open during testing...
Useing engine restore, (the name of the additive) avail at walmart and anyauto parts store is about $10 a bottle for a v8 chenge oil and add, recheck compression after you drive a couple hundred miles . You may need to use a bottle and a half since the v8 size is not based on an 8qt engine fill. And yes you should use with every oil change.
Useing engine restore, (the name of the additive) avail at walmart and anyauto parts store is about $10 a bottle for a v8 chenge oil and add, recheck compression after you drive a couple hundred miles . You may need to use a bottle and a half since the v8 size is not based on an 8qt engine fill. And yes you should use with every oil change.
My Nikasil engine '00 XK8 measured 145+ on all cylinders with 106k miles, warm engine, throttle open. I was very, very pleased with that.
The secondary tensioner job is very easy. If you can figure out how to get the valve cover off you can change the tensioners yourself. Other than the lock down tools it can be done with a $10 set of 1/4" sockets and a 10mm Allen wrench. The primary ones are another story. If you have not seen it, here is a link to about the best pictorial of the work I have seen. http://www.mediafire.com/?mijhydngtog
The tensioner parts are available from a Ford/Lincoln dealer to fit the '00-'02 Lincoln LS. The best price I found last Spring was $53/$56 from Silver State Ford. The parts box says JAG on it and are about 60% of the best prices from any Jaguar source. Careful, there are still an occasional eBay listing for tensioners that are the white plastic, spring assisted, 2nd generation.
The tool set is available from these guys for what amounts to $25 plus shipping. http://tiny.cc/Tools123
The secondary tensioner job is very easy. If you can figure out how to get the valve cover off you can change the tensioners yourself. Other than the lock down tools it can be done with a $10 set of 1/4" sockets and a 10mm Allen wrench. The primary ones are another story. If you have not seen it, here is a link to about the best pictorial of the work I have seen. http://www.mediafire.com/?mijhydngtog
The tensioner parts are available from a Ford/Lincoln dealer to fit the '00-'02 Lincoln LS. The best price I found last Spring was $53/$56 from Silver State Ford. The parts box says JAG on it and are about 60% of the best prices from any Jaguar source. Careful, there are still an occasional eBay listing for tensioners that are the white plastic, spring assisted, 2nd generation.
The tool set is available from these guys for what amounts to $25 plus shipping. http://tiny.cc/Tools123
120 is decent for the age/mileage and its fairly even. Off course it also deepnds on how he did the test, was it both wet and dry to check the true sealing of the rings or valves. And did he have the throttle blocked open during testing...
Useing engine restore, (the name of the additive) avail at walmart and anyauto parts store is about $10 a bottle for a v8 chenge oil and add, recheck compression after you drive a couple hundred miles . You may need to use a bottle and a half since the v8 size is not based on an 8qt engine fill. And yes you should use with every oil change.
Useing engine restore, (the name of the additive) avail at walmart and anyauto parts store is about $10 a bottle for a v8 chenge oil and add, recheck compression after you drive a couple hundred miles . You may need to use a bottle and a half since the v8 size is not based on an 8qt engine fill. And yes you should use with every oil change.
Interesting recommendation on the Restore. Reading about it on the internet (which always has nothing but accurate and well researched information!
), the thoughts have seemed to have been mixed on it, with mostly people who have used it saying good things, while the rest are all people who have religious views on any additives. Glad to hear your results have been different.
My Nikasil engine '00 XK8 measured 145+ on all cylinders with 106k miles, warm engine, throttle open. I was very, very pleased with that.
The secondary tensioner job is very easy. If you can figure out how to get the valve cover off you can change the tensioners yourself. Other than the lock down tools it can be done with a $10 set of 1/4" sockets and a 10mm Allen wrench. The primary ones are another story. If you have not seen it, here is a link to about the best pictorial of the work I have seen. http://www.mediafire.com/?mijhydngtog
The tensioner parts are available from a Ford/Lincoln dealer to fit the '00-'02 Lincoln LS. The best price I found last Spring was $53/$56 from Silver State Ford. The parts box says JAG on it and are about 60% of the best prices from any Jaguar source. Careful, there are still an occasional eBay listing for tensioners that are the white plastic, spring assisted, 2nd generation.
The tool set is available from these guys for what amounts to $25 plus shipping. http://tiny.cc/Tools123
The secondary tensioner job is very easy. If you can figure out how to get the valve cover off you can change the tensioners yourself. Other than the lock down tools it can be done with a $10 set of 1/4" sockets and a 10mm Allen wrench. The primary ones are another story. If you have not seen it, here is a link to about the best pictorial of the work I have seen. http://www.mediafire.com/?mijhydngtog
The tensioner parts are available from a Ford/Lincoln dealer to fit the '00-'02 Lincoln LS. The best price I found last Spring was $53/$56 from Silver State Ford. The parts box says JAG on it and are about 60% of the best prices from any Jaguar source. Careful, there are still an occasional eBay listing for tensioners that are the white plastic, spring assisted, 2nd generation.
The tool set is available from these guys for what amounts to $25 plus shipping. http://tiny.cc/Tools123
Your 10.5:1 compression XKF at 145 makes my 8.5:1 compression XJF at 120 ish sound about right!
Good to hear about the Ford parts working. Makes sense, of course, but never would have occurred to me. I will be buying the parts locally either from Jaguar or Ford. Certainly will not be putting in any tensioners with plastic parts!
Thanks!
Guest
Posts: n/a
Hi Folks.
Compression test - Had the mechanic do a compression test, and I got the following results:
Left Bank Right Bank
115 115
120 119
120 120
125 125
Surprisingly consistent, side to side. The spread between them is good, but I don't know what kind of numbers I should be looking for. Is the 120 area decent compression for a 70,000 mile, XJR engine?
If anyone can check these for me, I would really appreciate it!
Thanks
Erik
Compression test - Had the mechanic do a compression test, and I got the following results:
Left Bank Right Bank
115 115
120 119
120 120
125 125
Surprisingly consistent, side to side. The spread between them is good, but I don't know what kind of numbers I should be looking for. Is the 120 area decent compression for a 70,000 mile, XJR engine?
If anyone can check these for me, I would really appreciate it!
Thanks
Erik
It is just a rule of thumb really but new cylinder compression results are achieved by multiplying the compression ratio 8:1 (turbo) or 9.5:1 (non-turbo) by the atmospheric pressure (using approx) 15psi at sea level (= 1 bar in European speak). so an engine that has 9:1 pistons should provide (9x15) 135psi when new, or 9 bar as we call it here, at sea level. An internal combustion engine won't fire under 60psi (4bar) so any improvement to above 100psi is most welcome in a bad nikasil engine. we are getting great results with nikasil engines here in Europe by going down the spark plug holes with 400ml of ametech engine restore oil (copper silver lead particles) then sucking out the excess. some dead cylinders at 10psi lift to 100psi with a single dose of the ametech oil down the spark plug hole. then if you repeat the dose and spin the engine again it can climb to 130 psi after a couple of treatments. i use a syringe and a piece of petrol piping to suck out the excess oil into a clean jam jar to reuse on the next cylinder and so on.
here are some nikasil related hints from their UK site under FAQs
QUOTE
Quick fix for worn cylinder bores. This is like a dry/wet compression test (also called a leak-down or leak-by test) usually carried out using regular engine oil. By using ENGINE RESTORE oil in place of the regular engine oil you can repair the bores at the same time. Try dividing a litre can of RESTORE down the empty spark plug holes (or glow plug holes on a diesel) and turn the engine over a few times before replacing the plugs and firing it up. It will smoke for a while then the compression should improve across all the cylinders. It is worth a try - doesn't work all the time - depends on how bad the bores are.
UNQUOTE
http://www.americantechnology.co.uk/...onials-4-w.asp
If one cylinder compression doesn't lift on the dry/wet leak-down test then you can assume the problem is a burnt valve or valve seat. In this case the cylinder head must come off.
Hello,
how do you make sure throttle is wide open during compression test when you are alone?
<<<Mathew>>>
how do you make sure throttle is wide open during compression test when you are alone?
<<<Mathew>>>
Throttle was blocked open for tests. By wet, if you mean something shot into the cylinders, then no. Engine was on the coolish side when it was done.
Interesting recommendation on the Restore. Reading about it on the internet (which always has nothing but accurate and well researched information!
), the thoughts have seemed to have been mixed on it, with mostly people who have used it saying good things, while the rest are all people who have religious views on any additives. Glad to hear your results have been different.
Interesting recommendation on the Restore. Reading about it on the internet (which always has nothing but accurate and well researched information!
), the thoughts have seemed to have been mixed on it, with mostly people who have used it saying good things, while the rest are all people who have religious views on any additives. Glad to hear your results have been different.Thread
Thread Starter
Forum
Replies
Last Post
FS[SouthEast]: 2005 Jaguar XKR Convertible Supercharged
divingmom
PRIVATE For Sale / Trade or Buy Classifieds
0
Aug 25, 2015 07:54 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)








