964 valve covers - why do they continue to leak?

[DW SD]

Hi All,
Small frustrating situation.

The engine (3.6) was rebuilt about three years ago and has 3k or 4k miles. I drive it about once a week, but am working to improve on that

I am having trouble getting the 964 lower valve covers to keep from leaking. A few weeks back I installed the Hargett billett valve covers thinking my factory originals were a bit warped. I figured I'd spend the $280, replace the valve cover gaskets and be done with this issue for while. No dice. While they leak less, both remain. I run my finger along the bottom side of the lower valve cover and pick up a total of a drop or two of fresh oil. Pi$$es me off, frankly.

I've replaced countless other seals in other cars and engines, understand not to over or under torque and begin the torquing process at the middle, slowly working my way around in a circle pattern through several tightening rounds. Am just a little baffled. I'm using a 1/4 socket driver, 10mm, hand-snug. My larger snap-on torque wrench doesn't fit without the swivels, which I think would throw off the readings anyways.

Should I be using something like curil - T or another sealant?

As always, thank you,

Doug

[Flieger]

Are all your rocker shafts in alginment?

[DW SD]

Flieger,
Thank you for the reply. I don't know? As I said, the engine has 3k to 4k miles since rebuild. It has had two valve adjustments, too. I did the first one after break in and the builder did the second one around 2k miles.

How can I tell?

Doug

[Flieger]

Sounds like this is not very likely considering the recent services. The mechanic (you or anyone else) should have seen anything wrong.

[DW SD]

thank you for the picture. where would those leaks show up? would they come from between the head an cam tower from the backside? I know gravity will take its course. I agree that the rocker shafts are a longshot, given history.

Is anyone else using a sealer to get these covers to seal? Seals are Victor Reinz brand, labeled OEM by Pelican.

Doug

[pantera]

I'm going through the same scenario of my Hargett valve covers leaking on my 3.6. I posed this same question and was told most defintely apply the valve cover gaskets dry. Well, they are leaking. Anybody have recommendations for a dressing? or any additional advise.

Thanks,

Dan

[Flat6pac]

The #6 in the picture isnt deep enough in the larger boss.
Bruce

[pantera]

Bruce, thanks for the quick response. Are you saying I'm having a problem with the rocker shaft? The engine has never been apart that I know of and the car only has 44,000 miles on her. I'm hoping to put some kind of dressing on the new valve cover gaskets and call it a day or am I being ignorant?

Dan

[snbush67]

The rocker shaft is a common place for leaks. Often leaks from higher places on the engine appear to be lower valve cover leaks. The valve cover being the lowest points on the engine is simply where the oil drops end up.

Another common place for leaks that appear to be coming from the valve cover is the cam shaft seal.

I personally changed out about 3 sets of gaskets and resurfaced my valve covers etc. Before really getting in deep and realizing it was my cam shaft seal. This was confirmed upon tear down and subsequent rebuild.

The first thing to do is to eliminate the possibility of the rocker shafts leaking, to do this you need to look and ensure that your rocker shafts are tight and that they are centered on the rocker. If you notice in the pictures posted above the rocker shaft bore have a thick side and a thin side. The edge of the rocker shaft on the thin side needs to be flush with the edge of the housing. The edge of the rocker shaft on the thick side should be in about 1/4" or .5cm.

If the shafts aren't in properly the shaft will not expand using the pinch bolts, and oil could squeeze through the ends and dip out ending up dripping from your valve cover nuts.

Once you are sure your rocker shafts are right, and you have eliminated the other possibilities and you still have leaks then it is likely you have a bad cam shaft seal.

Good Luck,

Shane

[pantera]

Shane, thanks for the detailed explanation. I understand now I'm going to have to investigate this furthur and I thought this was going to be a quick fix.

Dan

[mca]

I'd try the silicone gaskets if they make them for your car. Full silicone - not just paper with the bead. They are reusable as well. Nearly 9k on my rebuild and no leaks.

I do have a weaping chain housing seal though - grrr.

[snbush67]

You can add a fluorescent die to your oil and then use a black-light to see where your drips are coming from. I have never done this but have read on this forum of people having success using this method. It is common to find the die at most automotive parts stores.

[Flat6pac]

Click here: Set the valves - Pelican Parts Technical BBS

Thats my posting and it shows the rocker shafts moving off location. I had a 40k miles 94 in the shop with rockers off location causing major leaks.
Bruce

[pantera]

Thanks guys for the help, really appreciate it. As far as I know they don't make silicone gaskets for the normal aspirated 964. Had them on my SC and they were great. The dye sounds like a good idea.

Bruce, what prevents the rocker shafts from moving off location? A C-clip of some kind? Sounds like a engine drop to fix.

Dan

[Flat6pac]

On a C2 you have the r[U]bber beads that fit into the covers. Its so much work taking all the insulation off a C2 to set the valves you want it right when you put it together.
The rocker shafts need to be located properly and tightened snugly, about 15 ft#. You cant get a torque wrench in the area so thats why I said snugly.
The rockers are being hammered all the time and thats why as part of a valve adjustment it is important to view all the shafts. The torque is what holds them in place and its not an engine drop, just contortion...
Bruce

[pantera]

Bruce, thanks. I did a valve adjustment about 5000 miles ago when the engine was out for a clutch. I simply didn't look for this. I have to double check the rockers once I get the valve covers off.

Again thanks everyone for your posts. Huge help!

Dan

[Flat6pac]

On a C2 you have the r[U]bber beads that fit into the covers. Its so much work taking all the insulation off a C2 to set the valves you want it right when you put it together.
The rocker shafts need to be located properly and tightened snugly, about 15 ft#. You cant get a torque wrench in the area so thats why I said snugly.
The rockers are being hammered all the time and thats why as part of a valve adjustment it is important to view all the shafts. The torque is what holds them in place and its not an engine drop, just contortion...
Bruce

[snbush67]

Bruce,

Your thread didn't load in your above post. Here it is for reference, great Job!

Set the valves

Shane

[DW SD]

My new Hargett valve covers are leaking on a fresh engine rebuild ~ 2.5 years and maybe 5k miles. I had assumed it is not the rocker shafts. Is this a reasonable assumption? I trust the builder and he is thorough. I did have fresh oil at the base of one cylinder adjacent to the cooling shrouds on the bottom of the cylinder.

I had actually considered that maybe it was the nuts leaking, as I re-used the nylocs, but then I remembered the gaskets surround each stud, so they shouldn't leak down the stud and through the nut. But....oil is seeming to collect on one of the nuts.

Doug

[snbush67]

Doug,

This simply can not be answered definitively. You could post a pic but as I stated above, the oil flows down and is going to end up on the lowest point. You have to find the source of the oil based upon the trail it leaves. You have to use die or powder to find the trail.

Yours could be a leaky valve cover gasket, you could loosen the bolts and torque them making sure you start in the center and work your way out in sequence, I would recommend fresh hardware.

Shane