WHB Porsche

Hey all. There's a leaking right lower valve cover on a car that's currently undergoing a PPI for me. I believe the stock valve covers are plastic (perhaps because there are aftermarket metal versions), and I'm wondering if they warp. Does the gasket alone need to be replaced, or should I be looking for a new valve cover as well?

Thanks in advance fellas,
Charlie

Full Boost

Charlie,

1 - Yes. Stock valve covers are plastic.
2 - Yes. There are aftermarket versions. I have never seen one in the flesh however they seem to be a nice mod - anyone?
3 - Yes. Stock ones warp.
4 - Yes and no. If you have the gasket off (or it is leaking) unless you can see the warpage (try resting it on a true metal surface - the gaskets could just be old. If wapred - I would change for the stock one... they have last 10 or so years now....

Hope this helps,

Simon.

WHB Porsche

Thanks Simon. I wasn't planning on replacing with non-stock, it's just that the only reason I guessed factory is plastic is the fact that aftermarket billet ones exist. Thanks for the quick response, much appreciated!

WHB Porsche

Another question: looking on Pelican parts, I can't seem to find a Turbo specific cover. Are there different Part Numbers for Turbo/NA lower valve covers?

kurtv

The 993 TT has plastic lower valve covers which leak over time due to warpage of the covers. Repairs may require replacement of the cover and gaskets. I had this done on one side of mine. The cover and gasket cost about $220 but it required about $400 in labor to install. I saved some since I had my turbos rebuilt at the same time.

Jay993turbo

You can install billet aluminum valve covers as I did, they are not needed but nice. I bought the twin plug version. I used a thin coat of curil-t on both sides of the rubber gasket and have been absolutely bone dry, no regrets.

911/Q45

I seem to remember Kevin warned that leaky valve covers are often a sign of worn valve guides resulting in high crankcase pressure pushing oil past the gaskets. Made sense to me.

Jay993turbo

You really should perform a leakdown test before making that assumption. Worn guides can cause a positive pressure situation which may force a leak. But this is most certainly not always the case. These covers are prone to leaks regardless. Just my 2 cents.


Jay

WHB Porsche

Thanks for all the feedback. Is the stock lower valve cover the same as on the N/A cars? If not, does anyone have the part number? Thanks.

Felix

Part numbers different from Porsche because the cut-outs for the second set of plugs isn't there. PET says 993 105 117 50 with left and right the same.

ScottMellor

Ooooooooohhhhhh. Twin plug billet covers. Droollll... Me want.
Oh great, now I've found something that I do not have and do not need and have to have.
Thanks a lot!

911/Q45

Scott, next thing after purchase would be you under there polishing them-control, control!

Droops83

Leakdown test won't always tell you about valve guides. However since we are talking about valve covers, the guide wear can be assessed while the covers are off by measuring side play of valves, and you will see if you need to do more engine work . . .

chris walrod

But perhaps poor leakdown numbers resulting from bad guides via beat-up valve seats might be accurate.

vrus

Jay.. where do I buy those covers? Those look amazing and I want to add them when I redo the motor.