Chevy Nova Forum banner

1 - 13 of 13 Posts

·
Premium Member
Joined
·
773 Posts
Discussion Starter #1
Hi Everyone,

My 350 ( 30 over ) is using an extreme amount of oil. Sometimes about a Qt. per 100 miles ? It does not seem to smoke and the plugs do not look bad. I do not have any external gaskets leaks. Any ideas? I did a compression test a while back and all cylinders were 205-210 cranking to the highest pressure and I think 160-180 with 4 puff method. Car has a roller cam and everything looks relatively new. Is there a way to determine if the rings or valve seals are the issue. I also hear that the rocker studs could suck oil if not sealed when installed, not sure if thats true or a myth.

Thanks for the help !
 

·
Premium Member
Joined
·
31,194 Posts
Check your PCV it may be stuck open and sucking oil into the engine.
 

·
Premium Member
Joined
·
8,050 Posts
Were the heads surface milled a large amount? Sometimes when the heads are cut the heads and intake have a large gap. It allows oil to be sucked in the gap between the bottom of the intake and heads. Unless the intake is cut to match or you use really thick gaskets the oil is sucked up from the valley into the bottom of the port. Normally it will cause the engine to spark knock really bad and foul plugs.
 

·
Premium Member
Joined
·
773 Posts
Discussion Starter #5
I know the oil rings have nothing to do with compression but would it be safe to say if the compression is good your oil rings should be good also or is it possible to have bad oil rings and good compression ? I will check the PCV when I get home.

Thanks Everyone
 

·
Premium Member
Joined
·
31,194 Posts
They could be in wrong, the gaps could be lined up or they could be upside down, this will allow oil to seal the cylinder during a compression test and burn it while running. I strongly recommend a good diagnoses before opening it up though.:yes:
 

·
Premium Member
Joined
·
8,405 Posts
When you did the compression test did you examine the plugs? If it's burning oil it should show evidence on the plugs.
 

·
Premium Member
Joined
·
4,125 Posts
My first thought was PCV, but If it's a stuck PCV valve, I would think you'ld see oil smoke for the amount you say you're burning. Plus as Paul said, your plugs would show signs.
 

·
Premium Member
Joined
·
773 Posts
Discussion Starter #9
The plugs looked great when I did the compression test. All were a very light tan nothing black or sooty on any of them. I am going to pull them again tonight and check. I agree with that much oil consumption I can't understand why I'm not seeing more smoke. Just a little baffled here !!
 

·
Premium Member
Joined
·
31,194 Posts
Put you finger in the tail pipe and feel if it's oily.
 

·
Premium Member
Joined
·
13,309 Posts
Only 2 ways oils leaves a engine.. leaks or burns.. there is a 3rd.. but I generally dont see it in small blocks.. and that is from evaporation due to high friction and heat..... but 1 qt in a 100 miles should leave a nice big oil spot or a blue cloud..... Period!!!!!........ maybe the kebler Elves are siphoning it while you sleep!:rolleyes:

the evaporation problem was only a qt. in 2k miles and that was a 468 with 4.88 gears street driven running 210F
 

·
Premium Member
Joined
·
773 Posts
Discussion Starter #12
Ok I checked the tail pipes and both are very sooty black but not wet. Pulled plugs and they look bad. Even have some wet oil on the threads of all of them. Pulled carb and looked into intake and it does not look like the pcv is the culprit. The vacuum tap that is hooked to is on the runner to #8 cylinder so I assume that would only cause an issue with that plug. I will try to post some pictures. Looks like it may be serious. Oh well !!!
 

·
Registered
Joined
·
4,760 Posts
i know this sounds stupied but is the bottom of your car soaked in oil i bet you may have a rear main seal leak shoot i could be sprayin out the filter all that good stuff if your car was burning oil or your plugs got covered in oil they would foul check you radiator fluid and trans fluid as well
 
1 - 13 of 13 Posts
Top