Oil Dripping out of Spark Plug Hole
 

I recently rebuilt the motor. A 1991 3.6 964 and replaced seals, gaskets, bearings, oil tubes, freshened up the heads with new valve springs and guides. Kept original p and Cs but did replace the piston rings.

Oil still sweats at the left side valve cover and was dripping from the right hand side valve covers.

After removing the exhaust and re sealing the gasket covers, I still found some oil dripping out of the number 6 spark plug (lower one).

Any idea what this might be from?


Thanks!

Only a couple sources of the oil, past the valve guides or past the rings. Do a leak-down test to rule out the rings. You could drop the header on that side to check the exhaust valve guides. But that might be inconclusive. Not what you want to hear, sorry.

Rocker shaft leak?

Is the leak in the "vicinity" of the #6 spark plug or does oil leak out of the hole when you remove the plug? Two totally different problems. If it's in the vicinity it could be many different things. The fans air will push oil all over the place and end up far from the leaks origin. I would look at the following;

1. Gasket between cam carrier and tower (the part with the o-ring that's part of the chain box under the cam sprocket.)

2. The o-ring on the cam carrier.

3. Rocker shafts.

4. Cylinder base gasket.

I'm assuming when he said oil coming from the spark plug he looked in the cylinder with a light/mirror and verified there is oil in the cylinder. If not, then yes suspect what Lindy said.

Yep. What I was thinking.

oil leak
 

Hi Alex , U did a top end rebuild , in order to take the heads away from the the cam carrier u had to remove the rocker shafts to get 2 the nut below the rocker shaft so u take the heads apart .When u starting put it together did u make sure the the rocker shafts were positioned correctly if not u will get oil running along the shaft and down the cam carrier which is open and will see an oil leak .Also if the shafts r not properly positioned they will BIND eventually seize up