Hello, quick question. My 2000 xkr recently had a small leak from the driver's valve cover gasket. It was leaking on the exhaust manifold from around the bottom rear bolt and caused a small puff of smoke and odor. I had it replaced, I was busy and wanted it done sooner than a diy would allow. The mechanic I took it to was really professional and had an amazing number of good online reviews. The shop sent me step-by-step pictures and updates on what they were doing. They informed me, as they were replacing the gasket, that it had been replaced recently and the previous mechanic used some kind of silicone sealant, they then conjectured that that must have been the cause of the leak. All was well for a couple weeks. I have now noticed that when I push the engine, not especially hard but enough to notice the 370 under the hood, it again has a small oil leak around the bottom aft valve cover gasket bolt. I will be taking it back in, but wanted to see if anyone could throw me some quick advice about other possible causes. The fact the previous mechanic felt the need to put sealant on a gasket worries me. Thank you for any advice you could give.

--Axiom

P.S. I just got my dream car and i'm trying to keep her beautiful.

 

The valve covers are plastic. The are only tightened to around 10 NM, which to inexperienced hands may not feel tight enough. If they were over-torqued at some point in their history, they could be compression deformed or cracked leading to the leak.

Also, a tiny amount of RTV is supposed to be used on the timing cover seam, but nowhere else.

PS: Have your tensoiners been upgraded ?

 

Interesting, do you think that was what the last mechanic was trying to cover up? Do you you think I may need a new valve cover? I didn't know silicone was ever a good idea with a gasket. The pictures the mechanic sent me made it look like there was more than a little applied, had me worried. In answer to your question, yes, it has metal tensioners installed. Tensioners were number one on my list when shopping, I made sure my mechanic checked even though the carfax and service records had that upgrade recorded.

 

It is hard to speculate...a lot can happen in 15 years.

Only a tiny dab of silicone is used at each seam. I do not think that is your problem.

I would say first check if the torque is correct all around. It should be tightened in sequence of center 2 inner bolts first, then middle outer bolts then the remaining outer bolts, alternating sides.

You might want to next search the forum for full and part load breather cleaning instructions...since the problem could also be excessive pressure.

If that does not solve it, then remove the cover and inspect for a badly installed gasket or cover damage. Used covers are pretty easy to get on eBay if necessary.

 

Thank you, I appreciate the input. My mechanic said he is familiar with the 2000 XKR's, said he has a few come in. Also, I specifically asked him to check the pressure. I would hate it if they installed the gasket poorly. I'm thinking maybe they saw the amount of silicone and assumed that was the only cause. I will definitely do as you recommend and maybe I can buy a new cover and get them to install it for free, haha. Thanks again for the input, I hope I can handle it from here.

 

Had this problem on my 1999 xk8 after having tensioners replaced at indi jag shop. I had leaks at rear of both valve covers , when i removed them i found hair line cracks on both covers at rear outside

stud hole . these are the hardest to get at and mine had been over torqued . had to replace both covers, shop would not take responsibility.

 

This is where WhiteXRK was commenting on for sealant, it's the only place and if you have the chance after this you can post pics with your comments to show what he showed you ;-) (you might need a min # of post like 10 or so before you can)

 

I've come across a few with an annoying leak onto the hot manifold which I'm sure, as others have said, is the result of careless over torquing. The problem is once taken off, it's very difficult to see any crack in the Cam Cover because it's no longer under tension.




The ones I've seen have had crack at the places marked with a red line in the photo.

Cracks in metal such as cylinder heads or block is usually easy to find with a UV crack detection spray but if an equivalent product is available for plastic then I haven't found it yet.

Graham

 

Thanks for all the advice and tips.

@jamdmyers- I see what you guys meant now. I haven't done too many diy projects including larger engine parts and was not familiar with that, good to know. Also, I have not met the criteria but as soon as I am able I will post pics and my procedure for troubleshooting this issue.

@GGG- It seems that's exactly what the issue may be. That is the exact bolt and, being a tiny fracture as you suggest, would mean only when under higher pressure would the cover leak.

I was also wondering if anyone knows the part number for the driver's side valve cover. I have found a few different ones and I'm a bit confused. Thanks all around.

 

Graham

 

I believe the part no you are looking for is C2A1514 you can buy them new from gaudin jaguar for $250.00 or if you can find them on ebay used for half the price. Hope this helps.

 

I recently removed both my valve/cam covers and reinstalled new gaskets. I found that all the bolts have shims on them that prevents you from over torqueing the bolts on the cover with the exception of one bolt in the back on the top on both sides and it is different for a reason.

When I was installing the new gasket I found that you must have the bolts in the cover and you need to push the gasket behind the shim of the bolt if you do not do this you will have a leak. I would also recommend that you clean and make dry any place your new gasket is in contact with for a proper seal.