Since I put a breather with a builtin PCV on my 350, oil has been coming up the dipstick and it burns a quart a day. I saw an LT1 post with a similar problem, but I don't know if it applies to me. Is this a definate cause of the breather? Could I just put on a pcv valve and keep a breather on the other side? Any help would be greatly appreciated...

 

Doesn't sound good to me. I would reinstall the OEM PCV and see what happens as far as the oil consumption goes. You might have excessive blowby from the gasses going past the rings.

 

If you didn't have this problem before you switched then you need to put the factory pcv back in and a breather on the other valve cover would be fine. Are you running the present breather to a manifold vacuum source(you need to)?

 

The breather with the PCV valve the cheap Mr. Gasket brand, and I have it hooked up to the PCV vacuum port on the front of the carb. It seems to lack the internal pressure valve. The breather I have on the other side is an Edelbrock standard design.

If I somehow incorporated a OEM pcv valve into the cheap breather, could I eliminate the problem? Or should I just run a OEM PCV valve with a breather on the other side?

By rings, I hope you don't mean piston rings...

In this post, it attributes the problem to too good of ring seal. I don't fully understand this situation, and any expert advice would be appreciated.

 

im pretty sure he does mean piston rings

 

Oh yes, he does.

I used to have a Merkur which was a Turbo Coupe 2.3L turbo charged. The PCV was by the air intake behind the TB. When the PCV was not working right, it would blow the oil out the dipstick. The crankcase would be pressurised and oil would go out the only way it can. It would push the dipstick out even and spray over the engine compartment. A good metal brake valve (one way, from Mazda RX7) cured that problem.

In fact, if I am not mistaken, a vacuum crankcase helps the rings seal better.

 

I had the same problem, Oil spitting out my dipstick, and oil leaking out the back of my intake. After months if found out that the brand new pcv valve I put in was bad. Just replace it again and everthing was fine. To bad it took me 3 months and a drive cross county with a smoke screen.

 

thank god someone else is having this problem too. my car was/is doing the same thing. i parked it 2 yrs ago because of it and havent touched it since. was a tpi and the guy before me switched it to a carb and then shortly thereafter noticed the whole engine compartment covered with oil. my engine is a stock 305 with only 83k on it and i had a hard time believing it was junk already, most make it to 200k, so i parked it until i could figure out what to do. recently ive ran into many with this same problem and they all say they fixed it by correcting the pcv problems, not rebuilding! hopefully thats your and my problem as well.

good luck,
Nick J

 

Go get yourself an OEM setup and your problem will probably go away. The weight of the ball and pressure of the spring inside there are actually somewhat precise, and alot of aftermarket companies just don't have it down for some reason. I work at a parts store and get one of these every once in a while. I actually have to send PCV valves back as defective! Anyway a GM one is probably less than 5 bucks, well worth it.

 

Put a good one way check valve between the PCV and the vacuum source and see if it helps.

 

By one-way check valve, do you mean a valve that keeps air flowing only one way(, or those valves that keep liquid from creeping up a vertical tube)?

I'm thinking about just going back to stock. Besides, what are the advantages of breathers anyways?

 

Well... I'm already planning on tearing off the top-end and oil pan, to port and replace the cheap gaskets I put on there 3 months ago. I guess I'll add pulling the cam seals and everything else I can replace without hoisting the engine, since I think it ran pretty low on oil at some points. Fun, fun, and more fun...

 

I never cared for breathers. They just make the VC oily. Not to mention eht hood liner