Now it leaks a lot of oil

[FranksPlace2]

I bought my '77 911S in March and had the best Porsche mechanic in St. Louis do a pre-purchase inspection. I asked him to especially check for oil leaks because I hate oil leaks. The report came back "only seepage."

I went to St. Louis to pick it up and saw no sign of oil leaks. I drove it to New Orleans and when I got home it was leaking oil and continues to leak oil.

My mechanic says it is the seal between the cam towers and the heads. The mechanic of the Previous Owner did not use the right stuff. The engine has to come out to fix it. Of course "while its out, you might as well do a ring job, maybe a valve job, etc."

Is it really that easy to screw up a cam tower seal?

Frank

[GIBSON]

Frank
Yes, it's pretty easy to screw it up yet it's also easy to do it right.
A good, clean surface, the right sealing material (a matter of preference, but there are a couple of things that work well) and the proper torque and no leaks.
The other stuff, rings, valve guides etc, should be evaluated because this would be the ideal time to do it.

[Jim Sims]

Yep, failure to clean off the surfaces, failure to apply the new sealant evenly and completely and then repositioning/retightening after the sealant has begun to cure or is cured. Then if it's the original sealant time/heat/vibration, etc. could be taking their toll. However, I'd make sure it isn't items on the top of the engine leaking, with the oil running down between the fins and looking like a cam tower to head leak. The candidates on top are breather cover gasket, breather hose to oil tank, oil pressure switch, and engine mounted oil thermostat o-ring. Some of these items can only be inspected/repaired with a partial or full engine drop and probably induction system removal. I'd sure check these items before tearing into the top end. I hate leaks too. I have a 76 911S; just fixed all the leaks (fingers crossed for two weeks now). It was a lot of dirty work. Jim

[ChrisBennet]

Perhaps others can confirm this but I've experienced cases of motors being "dry" for ages only to start leaking when taken to the track. Perhaps the extra heat (like New Orleans) gets the juices flowing?
-Chris

[Thomas Owen]

One other thing that can leak and APPEAR to be the tower/head junction -> Rocker shafts. This is the first place I would look. Pull the valve covers and have a look at the end of the shafts.

[Superman]

My position on this issue has always been that the best you can do is to make sure your Porsche engine is always leaking clean oil. Having said that (a number of times), I have recently rebuilt my engine (broken head stud) and I am attempting to avoid all leaking. I'm almost there. I'll be putting the fourth intermediate shaft gasket on it tomorrow.

For folks who do not work on their own cars, a rebuild, or at least a service involving engine removal, is likely the only hope of a leakless engine. It is fairly labor-intensive to chase down all these leaks and "seepages". For those of us who do work on their cars, chasing down leaks is kind of a game. It's not a game for losers or giver-uppers. It's a game of patience and persistence.

[Steve Marshall]

There is some debate that in older motors synthetic oils find leaks that otherwise don't exist. Did you change the oil after you bought the car? Are you using synthetic? If you are, maybe you can cross your fingers and go back to regular 20/50. It's cheaper than the alternative and if it doesn't fix the problem you're only out $ 40.

[FranksPlace2]

Thanks for all the input. We (i.e. Randy Greff, my mechanic) are at stage 2 where the engine is completely cleaned and he is finding every leak source before dropping the engine.

Steve, I had this optimistic opinion that it was something simple. But I did not change the oil.

Chris, New Orleans at this time of the year is in the 70s & 80s. Of course the humidity is in the 90s!

Thanks for your comments.

I love this board!

[cegerer]

" ... the best you can do is to make sure your Porsche engine is always leaking clean oil."

Superman, I don't know if you came up with that but I'm LOL! -- Curt

[Tinker]

Frank,

I would try to cure the leaks without removing the heads. If the motor has never been apart or had the case inserts done, there is a good chance that you will pull a head stud when you attempt to put it back together. Then you will have no choice but to pull the whole motor apart $$$$.

Tinker

[john walker's workshop]

tinker's comments are correct. on a 2.7, a head R+R often leads to a complete overhaul. don't do it if it only leaks a bit, unless you really want to, of course.

[HarryD]

Hi,

My 2.4 l appears to be needed a rebuild due to a huge blue clould on decelleration (valve guides?) and an oil consumption of 1 qt every 2-300 miles. While I know I will need the heads done, how great is my risk of needing the studs time-certed? The engine has 112,000 miles. There are some seeps around the cylinders that appear to be where the heads meet the jugs.

My wrench tells me that I can let this go for quite a while with no adverse impact (except to my pride and my purchase of castrol one quart at a time).

Thanks.

[Wayne 962]

Having an engine burn that much oil is a very bad sign. Just bite the bullet and have the rebuild done - you can't be getting much power out of the engine if it's losing that much...

-Wayne

[Jim Sims]

I'll probably get flamed for this but a '73.5 2.4 l T doesn't always need to have the studs time serted if you stick with the cast iron cylinders. The cast iron cylinders do not cause as much thermal expansion stress as the aluminum cylinders did. This was the origin of much of the grief with the 2.7 l engines along with the increased horsepower, heat load from the thermal reactors and poor wearing valve guide material. There are 73.5 T's running around with their original cases and studs. You should get the stud hole next to the lay shaft time serted though and at your mileage while you're in there, new bearings all around (layshaft, connecting rod and main). Cheers, Jim