Can anyone recommend a sealant...

[Slam]

...for the blasted cam tower gasket on my early 944?

Second cam tower leak in 6 months; leaks at the front, onto #1 exhaust. Was super careful, checked torques on all bolts after one month to make sure nothing had worked loose. Didn't use sealant on the gasket - gurus say not to, Porsche says not to. I don't want to have to do this gasket again and this time I'm going to use a sealant. What do you folks use if you're stuck in this position like I am? Head surface and cam tower surface are clean and smooth - no gouges. Is cam tower warped? Is head warped? Head was sent to machinist first time I swapped it out. HG is holding fine. Maybe he goofed on the cam surface. Hope not.

Thanks for the help, gents.

[Razorback1980]

Slam...did they machine the cam tower surface? I wouldn't think you would want to do that. I'm trying to think here but wouldn't that move the lifters further down and may risk holding some valves open. But as far as the leak....anytime I can't get a gasket to seal, I use sealant even though it's not called for. One thing that comes to mind might be pressure in the crankcase. Is all the ventilation working properly? One other thing to check would be the oil return holes back to the pan from the cam area. If they are partially plugged and some compression is coming up into the cam area through valve guides, that may cause extra pressure up there even though the ventilation is working properly. Long shot, but I have seen it on one car before a very long time ago but it wasn't a 944. Might be something to check anyway. My guess is that it's going to be a mating surface problem...maybe an outward bend in the cam tower.

[Zero10]

Did they resurface the top of the head when it was gone over?
If so then it is possible that the cam tower is somewhat warped as well, and won't seal up unless it is flattened.

Otherwise you might get away with a sealant of some kind, but I don't know which one to reccomend.

[ae1969]

If you really have to....... a thin amount of Loctite 518 will work fine.

I used that on my oil pump.

[Slam]

Thanks, guys. Alex, I'm gonna try the Loctite this time round. Tom, the head was cleaned up but not machined - machinist said it was true. The cam tower wasn't machined for the reasons you outlined - it may be warped as Zero has suspected. One thing I didn't even consider was poor crankcase ventilation causing too much pressure. But even then it would blow out the oil filler before the cam tower leaked, I'd think. I checked oil return last time the cam was off - less than 6 months ago. The cam tower may be warped. I do have a spare, so what I should do is have that one checked.

Thanks again, guys. This is one I wanna fix because clouds of smoke behind the car make it undriveable. It's not clouds yet but it will be...

[Porsche-O-Phile]

JB Weld?

[Techno Duck]

Originally posted by Porsche-O-Phile
JB Weld?

Hell, with a tensile strength of 3960psi you probably dont even need to use the bolts to keep the cam tower on.

This thread is kind of a godsend, i am looking into changing the cam tower soon and i completley forgot one should have the cam tower decked before reinstalling.

Is it possible the head needs to be resurfaced also on the cam tower side? Or does the machining of the cam tower surface kinda make up for that fact?

[Razorback1980]

Hey Techno, IF I'm thinking right...you want to be careful how much you shave off the cam tower or the top of the head. The distance between the camshaft and the valves are set through those heights. If you shave the tower, the cam will move down that distance and open the valves that much more. If it's too much, the valves will remain partly open and you'll lose compression.

[Techno Duck]

Another good point here. So whats the consensus, deck the valve cover or install it wit the gasket / Loctite and hope it dosent leak?

[Razorback1980]

There are a lot of engines out there that do not leak. I think you have to find out what is causing the leak and correct that. Either the cam tower is bent or there are nicks somewhere or internal pressure or maybe something totally different. But I certainly have nothing against gasket sealer and would have no problem giving that a try too.

[many944s]

I had a similar leak on my old 87' 924s. No matter how many times I checked the cam tower or head for flatness, it would leak right under the front bottom bolt, and drip on the front exhaust port. I used grey "fujibond" which is a product used on almost every seam in a Subaru motor (even where the block halves are bolted together!) Clean the surfaces with a little alcohol, or brake cleaner, then apply a small amount of fujibond, install, and torque to spec. I never had a leak after.

Good luck,
Nick

[Slam]

Tom, gotta agree with you - I'm leery about having the cam tower decked, or the cam surface on the head shaved. Don't want to change static timing by having too much shaved off. What I'll do, I think, is use a sealant this time round. It may very well be that the cam tower is warped - didn't make or find any nicks last time it was off. I'm going to check the spare I have and compare it too the one in the car and use the one that's straight. many944s, my leak is exactly as you describe yours. Did you use fujibond with the gasket as one would with garden-variety gasket sealers?

Changing the gasket isn't tough, or expensive (by 944 standards), just a PITA and downtime for the car.

[hpaulb]

Heads only need machining on the cylinder side. Lifter clearance is checked when valve seating is done. Top of valve stem is ground to spec tolerance. Lifter takes the rest out. Use a sinicone sealant. It will take any spacing out and hold against presure.

[VINMAN]

You can try Hylomar

[Razorback1980]

Slam, did you get it fixed?

[Slam]

Haven't fixed it yet, Tom. Frankly, I just don't feel like it right now. Plus, every time I look at the car there's a list of "while you're in there" things to do a mile long. I'l order a cam gasket sometime in the next couple of weeks and maybe tackle it sometime in October. I did take it for a realxing drive through the fall colors last week, but by the time I got home I was trailing quite a cloud of smoke. I've also gotta send the injectors out to Witchhunter for a refurbishment, and that'll take time. A lot of folks recommend hylomar and I think I'm going to go that route - it seems to be tried and true, and I don't want to do this job again in the spring. This summer I spent more time tweaking and fixing than driving and I need a break from it.

[hpaulb]

Your using a rubber seal right? As opposed to the crappy cork ones.

[Slam]

hpaulb - the issue is the cam tower gasket, not the cork one at the rear of the cam. Strangely enough, I've never had a leak at the cork one!

[hpaulb]

I meant the cam tower. Thought they were available but I quess not. They always leak for me. Only buy rubber for any car as they take up spacing.
Not to say, not all rubbers don't leak. HaHa

[944 Ecology]

Like VINMAN says, use Hylomar.

Wonderful stuff, never hardens, works great!