Chevy 350 (tell me it isn't true.)

[4x4phil]

My truck is pushing oil out of the dipstick and the front main. It isn't overfilled. The only reason I could think it was doing this is cause somehow pressure is getting into the crankcase. Which leads me to belive that it's leaking through the pistons, or piston wall. If this is the case I have to rebuild the motor or buy a new one. Please tell me it could be something else and that I don't need a new motor. I'm hoping, praying that it could be something simple.

 

[I Lean]

My truck is pushing oil out of the dipstick and the front main. It isn't overfilled. The only reason I could think it was doing this is cause somehow pressure is getting into the crankcase. Which leads me to belive that it's leaking through the pistons, or piston wall. If this is the case I have to rebuild the motor or buy a new one. Please tell me it could be something else and that I don't need a new motor. I'm hoping, praying that it could be something simple.

It COULD be something simple. (I hope it is, for your sake) If you PCV valve is clogged, there could be some pressure building up in the crankcase. You may also have a different breather, usually on one of the valve covers....check 'em out.

 

[mbryson]

It COULD be something simple. (I hope it is, for your sake) If you PCV valve is clogged, there could be some pressure building up in the crankcase. You may also have a different breather, usually on one of the valve covers....check 'em out.

I'd check that. Good advice, IMHO.

 

[Shawn]

Do a compression test, that will tell ya...

I had the same problem once,,,,blow by...

 

[4x4phil]

I already checked the pc valve and it's working very well. I also pulled off the filler cap on the other side valve cover and stuffed a rag in there hoping it would act as a breather and it didn't help. I'll get a compression tester and see what it says. What kind of compression should it have? Does anybody else have any suggestions?

 

[4x4phil]

Just a thought. I have no vacuum lines on the intake. They all come off the carb and the pc valve is on the valve cover. I plugged one off behind the carb that was pretty big. Could that be the problem?

 

[chans]

The one behind the carb is for the power brake booster.

 

[4x4phil]

That's what I thought. I just plugged it and used the large vacuum off the back of the carb and the front to the pc valve. But unless I'm wrong the intake can in no way pressurize the crankcase and creates only vacuum....Right?

 

[spencurai]

you need to do a compression test and just make sure that compression is about the same across the board. It doesn't matter what compression you get as long as you are getting within 10psi across the board. IF you have a serious problem, you will see a drastic change in the cylinder with the problem.

 

[Shawn]

you need to do a compression test and just make sure that compression is about the same across the board. It doesn't matter what compression you get as long as you are getting within 10psi across the board. IF you have a serious problem, you will see a drastic change in the cylinder with the problem.

I dissagree. If you 80-90 psi accross the board you are just as fu@ked as if you had only one at 10psi.

Good pressure for a 350 should be in the 110-140 range.

 

[spencurai]

fine shawn...whatever.....gawd.....

 

[Tacoma]

now wait a minute! I drove across the country in a Wagoneer that can't have had more than about 100psi in any cylinder. Just empty the air cleaner housing every 500mi, you'll be fine. And run like, 90w.

heheh. Well, it made it home anyway! sheesh!

 

[Shawn]

fine shawn...whatever.....gawd.....

What?

Your opion is the only one that holds ground?
If you have a single cylinder that has a drastic change, then I would be looking at a valve which is not going to give you as much crank pressure as bad rings. It is rare that only one ring is going to go out.

But hey, what do I know.

 

[Tacoma]

apples and oranges.

You're both right.
If there is a radical difference in pressure from one cylinder to the next, something else is wrong. If the pressures are fairly uniform, that tells you something else.

If you're running low pressure across the board, then most likely your whole motor is jacked, for various reasons that are usually fairly obvious, or will become so with a bit more inspection.

that's all! No more coffee for you today!

 

[4x4phil]

Tacoma, you must have been a middle child. Looks like it's time to do a compression test.

 

[Shawn]

I know, I just like to push Spences buttons..........

 

[BCGPER]

Wow, guess I'm the dummy here.... Your PCV should go directly into the intake manifold, and not the carb. Hook it it to the "big" connection on the carb if you have too, otherwise directly to the manifold...... Also, a cylinder leak down test will tell you far more then a simple compression test.

I know, I just like to push Spences buttons..........

 

[Shawn]

Wow, guess I'm the dummy here....

ding, ding,.... we have a winner.......

 

[Tacoma]

Tacoma, you must have been a middle child. Looks like it's time to do a compression test.

hahah no, I was the alpha oldest boy, of 4. I've been practicing diplomacy lately LOL

Compression test is an excellent idea, or you could just say the hell with it and buy RichM's 305 and be done with it.

 

[4x4phil]

Well, aside from blowby I haven't heard any other ways that I could have pressure in the pan. Even though I have the pcv hooked into the wrong vacuum port it still has a really good pull. So, I found a kid that's gonna sell me a 400 sb. So I'm gonna send this motor to live with *****. May it rest in peace.