Replacing upper valve covers

[privatepang]

So seems like theres a leak coming from my upper valve covers. The lowers have already been replaced and wrench recommended changing the upper VC's

I did a search and found a lot of people recommending turbo valve covers but I assume its the lowers they are referring to?

Its a 2.7 from a 75 911s so just curious what other people recommend. Had a look at the sponsors aftermarket ones and look pretty sweet but other than that not sure if they are decent?

Is replacing them as simple as taking out the airbox, undoing the bolts on the valve covers and just replacing it ? Sorry for the noob question.

[Winter]

others will correct me, but I think that the lowers are the key with the turbo valve cover mod. you might consider the reusable silicone gasket, available from our host. If your upper covers are warped, you can use some sand paper and a sheet of glass, put the glass down flat on level surface, tape the sandpaper to the glass and then sand the covers down until flat. No i have not done this. but i did read it in a forum I post on from time to time

Good luck!

[DRACO A5OG]

Well you could remove them and have a machine shop lathe them to get them flat again. You can attempt to so it yourself using find grit paper and a mirror to check the evenness before and after

[KNS]

The upper valve covers are simple, just unbolt and remove. Leave the spark plug wires in place while you are undoing the nuts and while putting them back on, you don't want to drop a washer down the holes.

The red silicone gaskets are great, buy them once, reuse over and over without any leaks.

[Jerome74911S]

I'm repeating what others have already said, but here you go:

My engine is a '75S. I just put my covers back onto the engine this afternoon after doing a valve adjustment.

The quality of the castings from the early '70s is not great. My upper covers are pitted and rough, and this is the way they came from the factory. However, if yours have just begun leaking it may be due to some warpage of the covers. The often mentioned solution for this is to take a piece of thick plate glass (a perfectly flat surface hopefully), with some very, very fine sand paper on it and place the face of the valve cover (where the gasket is) against the sand paper and rub gently. Any uneven surface of the valve cover should be slowly ground down by this process. Be slow and careful.

The "turbo" valve covers you talk about are much better quality, at least on my car. On the 2.7 cars these covers are often found nowadays.

You do not need to remove the airbox to change the upper covers. Just take off the other junk so that you can get at them. Yes, it is a matter of unbolting the old ones and bolting on new ones, BUT, you must use new gaskets, washers, and nuts. And the torque on the valve cover nuts is very small, so use your low range torque wrench carefully.

[privatepang]

Sweet! That doesnt sound too hard. I'll give it a try and yeah i'll order new gaskets/washers.

[Sigurd]

Don't overtighten the nuts. Use a torque wrench.

[DRACO A5OG]

+1, A Micro Torque Wrench in inches, you only need like 8ft lbs

[jsmithcds]

Originally Posted by DRACO A5OG

Well you could remove them and have a machine shop lathe them to get them flat again. You can attempt to so it yourself using find grit paper and a mirror to check the evenness before and after

+1 local machine shop can machine those flat for $10. Make sure you retourque the valve covers after you take it for a good drive and gets it hot. They will accept some more wrench after they get hot.

If there is still a leak in this area after the above steps then......


Make sure your rocker shaft bolts are torqued down tight. Oil can slip by if they are not torqued properly.

Justin