hosrom_951

Did anyone experience a cylinder head gasket causing an oil leak onto the block?

Gator_86_951

Where do you think it is leaking from. I know you have had problems with the cork gasket on the back of the cam tower. My is currently leaking again, and it does sort of look like it is coming from the gasket when it isn't. I guess it is possible, but seems highly unlikely.

Porsche-O-Phile

What makes you suspect this? Do you have the dreaded milkshake?

hosrom_951

Ok, i replaced the camshaft housing gasket a few weeks ago, and yes the rear 'cork' gasket was replaced.

Ever since then, the car's oil consumption rose dramatically. Yesterday when looking for oil leaks, underneather exhaust header #4 i saw the cylinder head mating line with the block. From that line and onwards, the whole side of the block is just covered with oil, lots and lots of oil. It is leaking so much that the clutch bellhousing and the wastegate are covered in oil and dripping.

The only thing i can pin point is that i can see the actual headgasket squeezing out between the cylinder head and block, which got me thinking that it could be leaking.

I cleaned off that area, but just thinking if this could be the case?

Dave in Chicago

Yup. My 968 was leaking oil at the head gasket, down the block towards the rear. No damage to the car (yet), so this was a convenient time to PM the head gasket and do a valve job / variocam chain / chain pads.

Much $$$$, but you should see how close to failing the gasket was in numerous spots.

nine-44

Clean it off, let it idle and see where it comes from. I'd put money down that the cam housing didn't get torqued properly and is leaking. The oil port goes through there between the last 2 bolts on the bottom of the cam housing. I've done 3 of these now, all after the cam housing was off and not too long after they started leaking. I'd seriously put money on it, clean it up, check it out. Good luck

nine-44

Oh, tips, use the same socket-extension combo to torque all the housing bolts so they all see the same flex and final torque. Check the specs, but IIRC they go to 15ft lbs.

hosrom_951

The camshaft housing is bone dry, like i said i replaced the camshaft housing gasket and the rear gasket. Reason being was oil leaking from the housing onto the headers (#1 & #3) and dripped oil onto the oil cooler housing, p/s pump and so on.

Everything above the headers are bone dry, spotless. Underneath the headers, where the cylinder head meets the block is where the leak appears to be coming from.

That area is cleaned off now, i can see the bare aluminum block and cylinder head. Let it idle, no leaks, drove it for 10km, various rpms, traffic and so on. So far, it is not leaking from that area, but only time will tell.

shmucklebuckle

Yep, I just did a head gasket for exactly this reason. No more leak

hosrom_951

Do you recall where it was leaking from?

shmucklebuckle

Yes, it was leaking on the passenger side of the block, at the back, from the head gasket. There's an oil passage right there, and it was leaking from the passage to the outside, and running down to the back of the motor and oil pan. When I installed the new gasket, I used some RTV silicone on both sides of the gasket, on all the raised rubber "seal" lines to help. Make sure you don't get any RTV on the metal ring parts of the gasket though.

Chris White

Tough to say – my first guess is that you are looking at all the oil that dribbled down there when you took the cam tower off! It will pour quite a bit of oil down the side of the block when you pull the tower off.
It is possible that the oil return area of your head gasket has a leak – but this is non pressurized oil and it is not common for it to leak.
You mentioned consuming oil – at what rate? A very small amount of oil can make a big mess but if you are adding a lot of oil there might be other issues.
One of the big causes of leaks/consumption is ring wear – once the rings wear to the point of causing significant blow by the crankcase gets pressurized when on boost and that will really start leaks – just about everywhere.

Chris White

hosrom_951

Chris,
I had the exhaust headers taken off last week, i cleaned the block till it was bare alumiun. Today, i noticed that the oil leak is very small, but it is coming from the cylinder head.

As for the oil consumption, it is normal, it was probably all in my head, i have done 1,000+kms and still have the dipstick reading 3/4 full.

A reminder, this headgasket is the original 20-year old one, and i can literally see a rotton piece of the gasket coming from the leaking area.

Thanks again Chris

Chris White

If you don’t want to pull the head you may be able to get away with removing the headers again and giving the gasket area a real good cleaning followed by applying some good heat resistant sealant to the area. The area that is leaking is an oil return that is not pressurized so you might be able to keep it sealed.

Chris White

hosrom_951

To be honest, i was considering applying some high temp sealant there. But i was under the impression that it is only a matter of time before the head gasket slowly gives way and would need replacement.

Well....here is what i will do, i will clean that area and apply the high temp sealant. Then i would be able to get the headgasket kit, valve guides, and all the other bits to rebuild the head (or go for an upgrade if i can find a good used head in the US and send it for upgrades )

Thnaks a LOT Chris, really appreciate it.