Hi everyone,

This is a bit odd to me, I’ve owned my car for about 7 months and I did timing chains and tensioners when I got the car. I bought the whole kit from Christopher’s and it came with valve cover gaskets so I went ahead and replaced all the gaskets and applied some sealant on the areas specified by alldata and I torqued all my bolts down to spec and now 7 months and 5000 miles later it is leaking from both of the valve covers. I don’t get why? Any assistance would be appreciated, Thanks!

The timing cover doesn’t appear to be leaking though

 

the gaskets in that kit are trash. happened to another guy here too. get felpro for the lincoln ls 3.9

oil pools at the back edge and that’s where they always leak

 

What year is your car. The cam cover gaskets are different for the engines earlier than '99. AJ26 vs AJ27.

 

If the part load breather on the left valve cover is blocked it can cause pressure buildup, so you should check that.

Other things to check are the levelness of the valve covers, they can easily be over-tightened causing some warpage and subsequent leaks.

Also some owners have discovered hairline cracks in the valve covers, so a close inspection is in order.

I don't think the type of gasket is to blame, I don't think the genuine Jaguar gaskets seal any better than the Rock Auto ones.

Close inspection for trueness of the valve cover surfaces, inspection for any hairline cracks, and careful assembly without over tightening. Light use of silicone gasket maker can work, although I am rarely an advocate of gasket goop of any type.

I'm not sure why these valve covers have a habit of leaking, but they do have a history of being troublesome.

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I have a 2001 xjr which means I would have the AJ27

 

I just find it odd that both would be leaking if any of those were actually true. Like if the part load breather is clogged wouldn’t just one side leak. And I’m not gonna say it’s impossible that both would get a crack or both be warped at the same time but I think it’s pretty unlikely.

Maybe I will round up a set of new valve cover gaskets from rock auto just in case I think it’s the gaskets but I think I will pull off the covers and examine them to see if they’re warped or cracked and if not then I’ll install the new valve cover gaskets.


Edit “ I just checked the price for those Lincoln Ls Fel-pro gaskets, holy cow those are cheap right now. They’re $13.80. I will definitely get some of them ordered and probably just keep them if they don’t need them”

 

Looking closer it appears that you are leaking around the bolts. Did you put new insolators on the bolts. Also the bolt needs to be pushed through the covers gasket. You don't put the cam cover on the head and then drop the bolts in the hole, like valve cover gaskets back in the day. When you have the bolts installed properly you can turn the cover upside down and the bolts won't fall out.
Not sure if this is what happened but just trying to help figure out why they are leaking.

 

Yeah I believe I installed them correctly and I know I installed new ones, the gaskets kinda held the bolts to the valve cover. I kinda thought it looked like they were leaking from the bolts but when I thought about it more I figured that the area where the bolts go would be the easiest path for the oil to drop from. So I’m not sure whether it’s the gasket or the bolts gaskets

 

The breathers are "engine breathers", also called crankcase breathers. Any pressure in the engine/crankcase will equally reflect under both cam covers (the spaces under cam covers are connected through the crankcase).

 

really? I thought the passenger side had a full load breather and the drivers side had a part load breather. But I don’t know much about the breather system so you’re probably right. If I would clean the part load breather out would that fix the leak or would I have to take them off and replace the gaskets?

 

The part load breather may be blocked, but I'm thinking not likely, and if it does look like the culprit I would rectify, then clean the area around the valve covers, and see if they continue to leak.

But, I'm doubting the part load breather is the problem. I would replace all of the valve cover gaskets and "o" rings, and simply be extremely fastidious with inspection and cleanliness on the valve covers. As BobRoy indicates it does look like the leak is from the bolts, maybe use a small amount of silicone gasket maker on the bolt "o" rings? Also use some silicone gasket maker on the timing cover joint areas as recommended in the shop manual, and tighten to specs using the tightening sequence.