phil74501

Went out and started up my 944. I had the hood up cause I put some water in the radiator. I smelt something hot. Got to looking and notice some smoke coming from under the cam tower. It went away after a few minutes. It's not using any oil that I can tell. What could it be? Gasket?

PaulStewart

Cam box gasket, camshaft rear cover gasket, or camshaft front seal.

Are you about ready for a front service?

Did you change from dino oil to Mobil 1 recently?

phil74501

I've only had the oil changed once. It was Mobil 1. I've only had the car a about a year. Don't know what a front service is. As far as I know the gaskets are probably original.

Mighty Shilling

I had smoke coming from there when my slave cylinder went... it would squirt on the flywheel and then get thrown onto the exhaust... check your brake fluid level...

phil74501

Brake fluid was fine. I checked all of the fluids before I started it. I made a habit of that since I usually only start it every other week or so.

PaulStewart

Front service is the timing and balance shaft belts, rollers, and seals.

If the cam box gasket is leaking, the timing and balance shaft belts must be removed in order to install a new gasket.

Did it smell like burning oil?

phil74501

The belts were replaced before I bought it. PO said they had less than 1k on them. It does smell like oil. That's what makes me think it's a gasket.

PaulStewart

Where is the leak?

In any case, I would get that Mobil 1 out of there, I made the same mistake and have the same issue.

I'm due to change my belts, so I will fix mine later in the year.

hosrom_951

You do not need to remove the balance shaft belt to remove the camshaft housing.

The timing belt needs to be loosened and removed from the camshaft timing gear, it still stays on the crank, water pump, tensioner and roller.

Clean up the engine block, and look around after a few days for source of leaks.

Most probably either a camshaft housing gasket or the rear camshaft gasket.

When the front camshaft seal failed on my 951, it leaked onto the oil filter/oil cooler, but not near the headers to cause smoke and belts did not get wet/contaminated with oil.

eohrnberger

If you just changed it to Mobil-1, what weight?

I ask because I changed from whatever the PO put in to Mobil-1 5W30, and it was dissapearing on me. Seems to stay around longer now that I've switched to 15W50. Perhaps your situation is similar? I would imagine that the thicker oil would be kept in a little bit better by the gaskets and seals.

PaulStewart

You are correct.

But I NEVER reuse a timing belt that's more than 6 months old.

phil74501

It's 10w30 now. I have some 20w50 that I'm going to put in. One of these days.

PaulStewart

Put dino oil back in or the leak will get worse, BTDT.

KLR

Rear balance shaft seal leaks are common and will do this too. The back of the lower shaft is right above the crossover pipe. According to the wisdom of the list, this culprit can be successfully addressed with sealant or epoxy. This is a good thing, as there is no real way to get at this seal without removing the motor.