Part 2
after getting a Restricted performance fault
and did a COMPRESSION and cylinder leak down test
I have found cylinder 7 & 8 have lost all COMPRESSION
so started tear down
After removing intake manifold i can now see cylinder 7 & 8 have lost there valve seats on the last valve on each cylinder so now heads off


Also i have been trying to find gaskets for my engine
It is a 2004 s t 4.2 v8 non supercharged
I have asked a few sellers on Ebay but get the sane answer
Sorry not Compatible with your car or sorry dose not fit your car
Sorry if im wrong but i thought the xk8 with the 4.2v8 had the same engine

Is there any where i can find out what jaguar s have the same engine
where i can get a parts number list for gaskets

Engine swap is not possible as there are 4.2 for sale in new Zealand
thanking you
darrol

 

Use this website and buy from them or use the part numbers to search. Jaguarlandroverclassic.com is correct i think

 

Thanks

 

very welcome. It is a very thoruogh site and sometimes a little confusing. Make sure you follow the vin number exactly and you should be fine. Gaskets have an entire section to themselves. SNG Barrett is also very good and i think they have an outlet in Australia. Just use the exact number you get from jaguar classic and search the sng site that way. Many jaguar part numbers have been superceded over the years and the jaguarclassic site is always up to date

 

Burnt out valve seats are often caused by the combustion being too hot. A lean mixture can cause this. What could cause a lean mixture? Inlet manifold leaks. When you rebuild, take extra care to ensure the the mating surfaces are level and spotlessly clean, replace the inlet gaskets with new ones and replace the fuel injector seals. Failure to do so may see the same problem recur.

Also check to see if the brake servo pipe attaches near those two cylinders. It isn’t unheard of for a leaking servo to lean the mixture to the closest cylinder(s) and cause burnt out valves or seats. Also check for any other possible causes of unregulated air entering the intake (e.g. Leaking vacuum pipes, split breather pipework, hardened rubber seals etc.).

As you will have at least two spark plugs that are now ruined, you may as well replace all the plugs too. Make sure the new ones have the correct heat rating.

Hope you get her running sweetly again soon.

 

some of these engines don’t have great press fit and drop seats after a hard overheat.

it happening in normal operation is very weird, that’s a dodge thing…

 

yes i have read they can drop valve seats when over heat
I would like to say yes it over heated
but what is puzzling me is on the way home temperature gauge was sitting just under half
car was running fine
Until i stopped for a break and turned off engine
After that it run like crap