I think you can see in these pictures that the seat has dropped. Glad to have a second opinion. The pictures aren't great. I used a $20 borecope from amazon.

I believe in this image you can see the profile of the valve as well as the dropped seat. The valves are in the fully opened position in these pictures.



green arrow edge of valve. red arrow valve seat?




Alternate angle of previous picture




This picture shows both intake valves. The other valve seat appears to still be in place.

 

I would need to drink more to make much of those images. I would like to see a picture of the cam flats with the crank turned to line up the timing mark on the fly wheel with the sensor, but anyways, it would seem that some head work would be required.
But at 180k mIles, what else would you do, valves and seals? If that is a nikasil engine, wear should be minimal.
Would you do it yourself?

 

dsetter:
What you call the "runner" and is also called the slipper changes from white to that color with time, at least in the few examples I have looked at.

 

I'll snap a pictures with cam flats ligned up and a ruler across.

I'm debating what to do. I'm going to get some quotes on head work, if the head(s) are off it seems to make sense to have them freshened up.

I'm also going to talk to the mechanic who just did the time chain cover gasket. It's possible that durring the timing chain cover gasket replacement the fan harness was disturbed and thus why it it got cut in half by the serpintine belt, which lead to the vehicle overheating and the valve seat dropping.

I'm capable of doing the work excluding machine shop stuff. I have no doubt it would be a very significant time investment and also gaskets and machine shop costs are likely to not be cheap. If I tackle this I need to make sure it's a good use of my time and money.

Will update with more pics.

 

The fan assembly most certainly comes out with timing cover work, and I too would be looking at whoever carried this out.
The cheaper option is a replacement cylinder head, a much faster and cheaper job. Complete, just needs valve clearance check and fit.

 

If it turns out to be the grease monkey who fiddled with your car, i would be stringin' the b***ard up from the nearest lamp post!!

 

I talked to the mechanic and he was reasonable about the whole situation. They are in the middle of redoing the heads. According to the machine shop all the valves needed to be milled past spec, so they are recommending I replace the valves, all 32 of them!! Ouch

I started pricing out valves and they are quite expensive ~$20/valve. I found a few places selling aftermarket valves for cheaper. Jag PNs are exhaust NCA2532AA and Intake AJ810945 (supersedes NCA2533BA i believe). Best I can tell so far, naturally aspirated and SC use same valves.

In search for cheaper valves I looked to the lincoln 3.9L LS from 2000-2006. I found Exhaust XW4Z6505AA and intake XW4Z6507AA . Can anyone confirm or deny that these are interchangeable? I found one ebay seller specifically stating they were interchangeable, but would love to have confirmation from elsewhere.

In other fascinating news alibaba sells a variety of different jaguar valves (unfortunately none for my car). A few sellers will let you buy a small batch. Valves for 70-90s xj* run about .15cents a piece.

 

For historical record the ford valves did work. Car is running fine after a complete top end rebuild.

 

Interesting reading; I'll save this thread for reference as I'm about to do a compression test on my 02 XJR with 177k miles. No problems with the bottom after renewing the top end?


Mark
2002 XJR-100

 

hispeed,
I had 234K on my original bottom end when I had my heads milled along with the MLS head gaskets installed with a full valve job. That was 9K miles ago and still running strong. These bottom ends are stout. Besides running out of oil, the only other thing that'll kill the bottom end is engine overheating.

 

No issues on my end still running very strong.

 

Thanks for the replies about the bottom end. I figured that they were well built but needed the reassurance. Did my compression test and all cylinders were 120 or above with the highest at 135. But, this was a spur-of-the-moment thought to do the test, so the engine was cold as I have the SC removed to replace the knock sensors.


Here's another question: I haven't had to do any work with the SC removed since December of 2008, so I don't recall what the SC outlet ducts and spark plugs looked like when they were removed back then. This time, there is some oily residue puddled in the outlet ducts, but the residue at the EGR port on the intake appeared normal. The sparkplugs all had black residue around the perimeter with a good greyish tint at the electrodes. So, do these pics look normal? The SC duct pic is somewhat blurred, but you can tell that there's a puddle of gunk in the port.


Have a good weekend !!