Massive oil leak

[slamons]

Tell me why I have oil seaping out of all gaskets, I found slight kink in PVC / Vent line, Does a 390 need that much vacuume at the valve covers to prevent this problem??????

[papabug71]

I have been told they do. Gaskets fail, & leak with age. Are yours factory? Or has it been rebuilt at some point in time?

The rear main on my 302 is leaking like a sieve. But its an all original motor with 168K miles on it.

[slamons]

Thats the problem, New gaskets, New rear main, New intake, with carb. I did not have any problems until I changed over from the factory manifold to the edelbrock & holley carb. This did away with the old spacer under the carb with the vacuume ports, I attempted to re run the large pvc lines back out of the rear manifold port for ventilation. I did find that it had kinked but I am not sure if this would cause this amount of pressure leading to the seappage.

[QC]

Do you have a vent cap on the other valve cover( not the one the pcv valve is in) to let air in? If not you may be sucking the gaskets in.

[slamons]

Yes I have the oil cap on, I have it vented / grometted also going to the port to pull vacuume out...

[fordman]

what kind of gaskets did you use? cork or rubber? which ones are leaking all of them or just certain ones?

[slamons]

Cork gaskets, Pan and oil filter mounting plate, + a little out of rear main, All were new last year. It has less than 200 miles on it, I did have the same problem when I first started it last year, Once I replaced and ran the PVC hose and Large vac line it went away. I changed the oil last week, Drove to a small show about 20 miles, Found oil seaping from all these gaskets. Very frustrating.

[fordman]

cork will seep after a while once it gets soaked through. the pcv rattling doesn't always mean its good. is the hose clean that goes to it. once you got the kink out of it?

[mkpj1]

What's massive? I once built a 390 with a boat crank. Now that was a massive oil leak out the rear main! Did you have puddle or just some oil leakage. You realize the saying goes on these 40 yo engines,....it's not if but how much! So how much? Certainly a kinked PCV could increase crank case pressure. How do you have it connected to intake, on a T with other components, probably not good and sending it under the carb is better for spreading he fumes over all the cylinders. Suction at the bottom of the PCV valve when engine is running? Getting a edel manifold to seal on these engines is a true PITA. What's compression like, got good rings?

[71PA_Highboy]

Thats the problem, New gaskets, New rear main, New intake, with carb. I did not have any problems until I changed over from the factory manifold to the edelbrock & holley carb. This did away with the old spacer under the carb with the vacuume ports, I attempted to re run the large pvc lines back out of the rear manifold port for ventilation. I did find that it had kinked but I am not sure if this would cause this amount of pressure leading to the seappage.

You already ID'd your problem... You eliminated the PCV Spacer.

Either hookup the the PCV Valve to the PCV port on the carb or put the spacer back in and hook it up there.


Good luck.

Eric

[ToughOldFord]

You're not going to pull enough vacuum from an intake port and you are causing one of your cylinders to runs really lean.

[slamons]

Thanks for the input, I will work on it this weekend.....

[KF100TK]

Would i have the same problem if i use just the breathers that came with my new aluminum valve covers

[ToughOldFord]

You really should have the PVC.