Distributor oil leak

[Ferret]

Hello everybody! I got a strange problem and can't figure out what causes it.

While driving I smelt a lot of fumes inside of the car. My first guess was the exhaust leaking, but nope, everything tight. A second look threw me off, as I had quite a lot of oil on top of the intake manifold at the rear of the engine, just below the distributor (HEI). After disassembling the distributor to remove it from the engine, in order to rplace the gasket, I discovered to be a little oil spill inside the distributor head.

This can't be good, so I checked for the most obvious possibility: crank case ventilation. It works just fine. The PCV is working properly and the vacuum at the carburator base is strong enough to let feel the airflow on the breather of the opposite valve cover.

The question now is to why there is such an oil mess if there shouldn't be any? Everything else on the engine works fine too. The oil pressure while driving is always perfectly where it should be...

Any advice is welcome, as I am out of ideas and i don't want to do the job over again...

 

[TheHomie]

I had a problem with oil accumulating on the back of the intake manifold. It turned out to be a bolt on the manifold was leaking oil. The fan and the air when driving made it accumulate toward the back of the engine. Basically what I am saying is it could be a leak more forward. Also some of the aftermarket distributer hold down clamps have a lip on the ends that has to be facing up. If facing down it may interfere with the proper tightening. Cant think of anything else. (also check the fitting in the rear of the manifold. )

 

[pontiacgp]

Does your distributor shaft have a hole to release the oil pressure? I had the same problem with the stock distributor but not with an MSD distributor. Here is a picture of the hole that releases the oil pressure in the shaft of an msd distributor I am rebuilding

 

[Ferret]

I had a problem with oil accumulating on the back of the intake manifold. It turned out to be a bolt on the manifold was leaking oil. The fan and the air when driving made it accumulate toward the back of the engine. Basically what I am saying is it could be a leak more forward. Also some of the aftermarket distributer hold down clamps have a lip on the ends that has to be facing up. If facing down it may interfere with the proper tightening. Cant think of anything else. (also check the fitting in the rear of the manifold. )

I checked the bolts and they're all to specs, none was lose.The clamp can only be mounted one way, and it was in a correct position.

Does your distributor shaft have a hole to release the oil pressure?

Nope, no hole in it. The distributor was made by Chevrolet Performance. Here is the link to it on Summit Racing:
http://www.summitracing.com/int/parts/nal-93440806

It worked like a charm for 9 years now, until today, when i found the engine oil inside and below it... It was never pushed to any limits. Only recreational/casualy cruise

 

[pontiacgp]

there is some felt at the top of the distributor shaft. There is a seal under that that may be worn

 

[Ferret]

pontiacgp thank you very much for these two images! i will get to work tomorrow and see if i can break it down further! Good thing is, i won't have to wait weeks for a new seal! there's a shop no far from here that can recreate any seal or gasket as long as you have bits of the original one!