I have a 1975 Ford f350 300 i6. My problem is that there is an excessive amount of blow-by coming out of the hole where the PCV sits, the oil cap and oil dipstick. When the engine is running and I take off the oil cap, the thing smokes like a train and almost dies from loss of compression. When that happened, I put my hand over the hole to keep it running and I could feel I good amount of suction. I'm at a standstill on whats wrong with it, I can't figure it out at all. Any help would be appreciated, I will post more info if needed.
Thanks, Tom

 

Do a compression test.

 

Could I get a compression test at a Penzoil?

 

I doubt it. I looked at their site, no mention of services like that.

Is your engine overfilled?

If you have so much pressure that it is blowing oil everywhere, it's time for a teardown. You may have worn out rings, which really shouldn't blow oil everywhere, or a hole in a piston.

Is the oil contaminated?

Has there been a change in the way your PCV is hooked up?

 

Buy a compression tester you screw into each spark plug hole sequentially. Just like a doctor uses a stethoscope, this will check your engine health internally. It isnt real expensive, check the AutoZone site. They may even have them as free loaner tools.

 

I was told that if a ring was out that smoke would come out the exhaust but it doesn't.
I don't think the engine is contaminated because I have to replace the oil all the time from how much it burns.
As for the PCV, I just disconnected that because the compression got so high that it would just blow it out. Then, when it was in, it would push the dipstick out and cause a very bad oil leak.
I don't know if it has much to do with it, but not all of the vacuum lines are hooked up either.

 

Any luck? Mines doing this but not as bad

 

Not much, I've just had more guys telling me it's the piston rings busted out. I think I'm just going to drop the engine and take those pistons out. The truck isn't being used as much as it was so it shouldn't be too much of a problem. I'll repost on this thread if I find anything.

 

Okay thanks. Mines my dd so I kinda really hope that ain't it. There's alot of messed up vacuum lines and electrical so I'm still holding if I get them fixed it'll go away... Can't afford to rebuild the engine right now

 

My truck has a whole lot vacuum lines just missing so it's not idling very well while it's in gear but idles fine while in park or neutral.