"Wet" valve cover seal

[awolff280sl]

I changed my valve cover seal to stop the slow seeping of oil around the seam, but the same problem with the new one. Can't tighten the cover bolts enough to stop it without valve clanging. Can I or should I use some type of sealant?

[waqas]

- Did you make sure the mating surfaces were completely clean?

- Are you sure the leak is coming from the seal? (and not one of the bolts nearby that enter oil passages-- these bolts require thread sealant)

- Where exactly is the leak? (front of engine, left, right, rear, etc)

[Cees Klumper]

Perhaps the valve cover itself is not sufficiently flat. Don't overtighten the bolts either, that may exacerbate the problem; I think the right torque is 2 Nm but better check that.

[awolff280sl]

The surfaces were clean before the seal was placed.
The "leak" manifests itself as a very slow seepage of oil around 80% of the cover seal, moreso on the left side than the right. The front side the seal is dry. The left side and back side of the seal seem to be most affected and are glistening with oil once the engine warms up. After running an hour or so there is enough oil accumulated along the entire length of the seal to start to very slowly inch its way down the side of the block just a bit. It's not alot of oil that seeps at any given time, but if I forget to wipe it off at the end of the day, it compounds over time, gathers dirt, and messes up an engine that, up until now, hadn't been clean in 30 years. I believe the pupose of this leak is to prove how anal I've become.

[jeffc280sl]

Andy,

Maybe the towers under the valve cover need to be repositioned or they're bent.  Its possible if the valve cover bolts were tightened with a lot of force the the bracket could warp up so that it contacts the underside of the valve cover before there is enough pressure on the gasket to seal.

I don't use any sealant and the gasket doesn't leak.

[glennard]

The three towers should be bent enough so their tops do not touch the under side of the valve cover. There should be a gap between the top and and the under side so the three bolts can pull the valve cover lip down into the gasket and seal on to the head surface.  Check to see that the valve cover lip face is a plane and not warped.  The original bolts are short enough not to hit the cam shaft.  Towers should not be twisted under the head bolts.

[awolff280sl]

Thanks. All of the towers are a little bent, partly twisted, and somewhat mis-shapen and this would be the cause of the oil ooze.
I decided to try to straigten them out and in the process re-torque the head as per the good info laid out on this forum. As I loosened the bolt holding the foot of the last of the 3 towers, the foot of the tower under the bolt twisted, and the torque sheared off a leg of the tower just below its upper right angle bend! I removed the broken piece and finished re-torquing the head. The broken tower is stable, especially because the side clipped to the oil shower rod was not the side that broke. Nevertheless, I'll need to replace the tower bracket, and if not too expensive I'll replace the other 2 as well, since they are mis-shapen and may break next time the head is re-torqued. Does anyone have any suggestions about replacing these brackets because I will have to remove 6 head bolts entirely and also violate the re-torquing sequence to some extent?

[jacovdw]

Andy,

It is not that expensive to change the towers. I had to replace all 3 because the previous owner overtightened the valvecover resulting in 2 fractured towers (and a lovely loud tapping sound when the engine was running from bent towers rubbing against the camshaft).

The part number is: A 115 016 00 38

As long as you only replace one tower at a time, it should not disrupt your torque sequence that much.

Regards,

[awolff280sl]

Jaco,
Very encouraging, thanks!

[glennard]

Do one tower at a time to the proper torque-hot/cold rules.  Good time to re-torque the other (8?) head bolts.   And the ons and ons--adjust the valves, clean oil distribution tube, check cam shaft is in sync with crank, etc, etc.

[jacovdw]

Andy,

The torque value for the 3 valve cover bolts is 5 Nm.

[Cees Klumper]

Additional thought: as the car moves forward, gravity will pull stray oil towards the rear (alongside the engine / compartment as well as the underside of the car). When you then look at the car at rest, there can be oil in places where it did not actually originate, but 'travelled to'. The point being that as you inspect the car, you may start looking for leaks in places where there are none, only because a lot of oil can be in places where it accumulates as you drive 55 MPH or faster, and in actuality it may have come from leaks much farther towards the front. So 'follow the trail north' as it were.

[ja17]

Hello Andy,

Pay attention to these hold down straps the next time you loosen one of their head bolts. A big screw driver or wrench can be used to prevent them from twisting.

Resolve your hold down strap situation first. Next check the flatness of the valve cover by removing the gasket and setting the vavle cover on a flat piece of glass or machined surface.  Also check the flatness of the  head deck by setting a straight edge on it. I have seen the top top surface of the head left humped up in the middle after a warped head had been cut on the bottom.

These valve covers and rubber like gaskets are very good about forming a good lasting seal. No sealer is used and the gasket will continue to be re-usable as long as the rubber stays soft and pliable.  Over tightening is the biggest problem.  The gasket can be cut, or the valve cover can actually belly out in the middle. Damaged hold down straps and strange valve train noises can also be caused by ovetightening as mentioned.

[awolff280sl]

New hold down straps solved the problem, and I think I didn't screw up anything else. Thanks everybody!

[rwmastel]

quote:Originally posted by glennard

.... clean oil distribution tube ....

How?