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Graham,
I purchased this 2000 XKR a few moths back out of an estate, and it had been sitting for awhile. I decided to change all the coolant hoses, and I found puddles of oil in the intake system. I've since replaced the part load breather line (Which was full of oil, literally dripping out), and since I removed the cam covers for timing chain tensioner replacement, cleaned the breathers as well. New spark plugs, fuel filter, and of course the hoses I started after. The car starts okay, but has a hesitation when coming off idle..I had one local Jaguar repair shop tell me just do a compression test, and you will have a more complete engine picture of health. Makes sense to me, but I'll admit as I'm finding out, even though this car has only 37K miles, it appears much of the preventative maintenance wasn't done, or at least there was no proof of most of it being done, which IMO gets expensive. I do have a fear of doing the test...the results could mean big dollars to repair IF there is an issue. I work on corporate jets for a living, but have worked on cars my whole life, and determining where excess blow by was coming from was always straight forward, and usually if the breather isn't clogged the engine is shot. That's the scary part..Even with me doing the work, seems 6-8K to rebuild the engine isn't out of the question, but I have the cart before the horse now..Long answer to your question, but that's what's prompting it.
Jason
To check the fuel trims you need to own an OBD11 scanner and hook it up to the OBD port, normally under the knee pad.
Conversely I believe in the states some of your auto parts suppliers can run the tests (for a fee?)
Whichever way you go post the result here and somebody will be along to interpret them.
Robman25 is right in that the fuel trims should be checked. With oil in the air intake system, I presume you've done the routine clean of the throttle body, and the MAF sensor.
The worrying thing for me is the oil in the PCV breather pipes. From your description, the car sounds like a non-driver as a non-firing spark plug in a cylinder would be easy to spot while driving aka "lumpy" engine.
Have you run the engine with the spark plug covers off to see if which cylinder is proving to be the source of the blow by?
I have 103,000 miles on the odometer and I just did a compression check It was so easy, it was ridiculous. The test kit cost about $25 from Harbor Freight and the hose screwed right in to the spark plug hole. I didn't even need any of the adapters in the kit. The only thing keeping my dog from being able to do this is his lack of opposable thumbs. And a short attention span. There are two reasons my dog can't do this check. And he would probably chew the hose into bits. Three reasons, there are three reasons why my dog can't do this check.
Oh, there is a fourth reason. He is so darn cute.
Anyway, most of the cylinders read in the 130's. One was in the 120's and one was below 120. The manual says that there is no target number, instead all readings must be within 25% of each other. That seems to be a generous standard, but that's what it is.
A compression check is a very valuable test that can tell you a lot about the health of your engine.
If one cylinder reads low, add a little engine oil through the spark plug hole and check it again. The oil helps the piston rings seal. If the reading increases, your problem is piston rings. If the reading remains the same, your problem is valves.
The question should not be why do a compression check, the question should be why not?
It's so easy and informative.
Document the readings and over time you can track any gradual loss of compression in each cylinder.
That's all the reason I need.
