I need to replace my valve cover gaskets (and secondary timing chain tensioners) but it appears a previous owner must have glued the covers down because they’re really stuck. Any suggestions on how to remove them without warping the cover? I’ve pried on the reachable front part as much as I dare-even used my heat gun but the cover won’t budge. I’d appreciate any suggestions. Thanks.

 

Have you removed the three fasteners under the coil cover?

 

Mike,

Don't be offended by the question - you have removed the on-plug ignition coils?

Graham

 

Mike,
This post from David Yau has a link to a document showing the cover bolt locations and torques. There are 14 on each side:
https://www.jaguarforums.com/forum/x...4/#post2033797

 

Yes. I installed all new iridium spark plugs and all new coil packs but apparently oil is leaking through onto the #8 spark plug, shorting it out. The cure is new gaskets but the valve cover seems glued down tightly. I’m pretty sure I got all the mounting bolts loosened but the cover is immovable.

 

Yes. All bolts loosened.

 

RJ237, I think that you will agree that there are only 2 instead of 3 fasteners under the coil cover/ coil packs as there is not a fastener between the middle 2 spark plugs. I think that once TREETOPDADDY removes the fastener between the front 2 plugs and the rear 2 plugs, the cover will just lift off without any prying.

 

There are only 2 bolts between the coil packs and those are loosened as well. I fear that the cover is glued down and I’m going to have to pry on it. Thank you for your replies to my dilemma. I’ll post if and when I get the covers off.

 

That then is indeed a dilemma. Good luck resisting the persuasion to crack the cover.
FWIW: the upper rear screw on both banks is unique and should not be in the mix.

 

Obviously, it's been years since I last removed a cover, and never one that was glued on. Is it possible to work a razor blade in there at some point?

 

Instead of a razor blade, try a plastic clip pry tool.

 

That's a tough dilemma you face.
I saw one cam cover gasket replacement YouTube video showing copious amounts (of what appears to be blue silicone) glue applied to the cam covers and heads of the Jaguar 4.2 Supercharged V8 engine.. Probably sealed very well but clearly this bloke was not paying too much attention to the Jaguar Workshop manual which to memory states no glue is to be applied except a tiny amount on the small 4 spots where the timing case cover meets the heads. The poor soul who has to do this job again in the future faces the same dilemma you do in removing the covers....
If silicone has been used I don't think any amount of prying is going to budge the plastic covers, also silicone does withstand quite high heat so I wouldn't persist with the heat gun.
A razor blade or plastic clip pry tool as mentioned above may be the only option here.
After you have done most of the area it may them pry off. It's also not going to be too much fun removing the glue from the face of the heads. Cover the engine area well so nothing falls in the engine and use the right gasket removal/scraping tools that don't gouge the head face along with the right solvents etc. to prepare a clean surface.
Much care needs to obviously be exercised if you try this and I would keep the blade closer to the cam covers rather than the alloy head faces. I would think the cam covers may be okay to take a minor scrape or two as it may be unlikely that you would do any damage to the ridge where the gasket sits in place when tightened down but who knows?? Uncharted territory for me.
I would reach out to all the 4.0 and 4.2 litre V8 sub forum sections. You would think someone may have already faced this issue and tried a satisfactory solution.
Good luck.

 

“Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.” - Sherlock Homes”

Leaks from both the rubber seals and the plastic covers are such a regular issue, I would not be surprised at any extreme resolution applied by a PO.

Graham

 

Done!! As usual the fault lay with the operator rather than the car or the tool (I happen to be the tool). Anyway, with a little perseverance and additional bolt-twisting, not to mention speaking in vulgate, I managed to get the left cover off.

Tomorrow, on to the new metal secondary timing chain tensioner and, with any luck, reinstall action and on to the right side, humbled but more knowledgeable. Thank you to all who provided sympathy and sage advice.

Mike

 

Fecit

(one for the Irish and Latin scholars)

Graham

 

Well done treetopdaddy. I suspect many of us have been there...

Most of our personal Irish friends pronounce it with a hard 'c' meaning something completely different...

sorry for the OT

 

I'm having the same problem with cam covers.....You mentioned above that you finally succeeded in removing the covers and referred to "additional bolt twisting What additional bolts did you fined?
Thanks in advance for your help!