PVC upgrade or inefficient? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chris989 · 09-05-2018, 10:46 AM

Hello all,

New motor and yet another oil drip. The motor is fresh,5.7 negligible blow by.

I now have drip coming from the driver rear oil pan area. (not above) Every Chevy i have owned has its drip and I can't stand it.

Anyway,, I am going to pull and investigate. My feeling is I am still generating internal pressure that the PCV can not deal with at highway speeds. Are the TBI setups just not great at recovery? Should I add or upgrade the system? Is it the crank slinging oil on that spot?

Any insight would be great.

On my performance motors I just run two breathers to the air cleaner and never had a problem, those motors have much more blow by at 6,000 than my TBI

CHris

SunSoaked · 09-05-2018, 02:55 PM

Buy a Harley. You'll forget all about the Chevy. ...and lots of cat litter.

Pontiac1976 · 09-09-2018, 10:10 AM

I assume it 85 up motor should be a one piece oil pan gasket. check bolts that they loosen off. Did you put a new rear main seal. Is the or pan gasket smooth flush at the mating areas, sum blocks the two main rear bolts on the pan need a little dab of silicone
on the thread of the bolt because they go all the way throw in to the oil area some time leak. Make sure the silicone has time to dry before getting oil on them or driving.
Not sure on the breathers as long as it's not clogged one side air coming in one side gases pulled out burned in the TBI or the older carb set up.

chris989 · 09-09-2018, 11:07 AM

Update,

Pulled the pan and converter cover. It is not the oil galley plugs on the back of the block.

It appears the leak was at the very rear corner of the pan, the gasket was a one piece and it had silicone in the corners. I replaced the gasket and PCV valve,, time will tell.

The PCV valve was working but it did not flow as well as the new one so I am hoping it was the cause of my leak.

mikebte · 09-10-2018, 04:18 PM

Quote:

Originally Posted by chris989

Update,

Pulled the pan and converter cover. It is not the oil galley plugs on the back of the block.

It appears the leak was at the very rear corner of the pan, the gasket was a one piece and it had silicone in the corners. I replaced the gasket and PCV valve,, time will tell.

The PCV valve was working but it did not flow as well as the new one so I am hoping it was the cause of my leak.

Do you have any numbers on the old PCV valve to run. Is it possible its the wrong valve? 305 and 350s had different ratings on the valve and I know sometimes the "universal" valve gets sold over the counter and is not correct for a TBI 350.

chris989 · 09-10-2018, 04:59 PM

Chevrolet Performance PCV Valves 6487779

09-05-2018, 10:46 AM	#1
chris989 Registered User Join Date: Dec 2011 Location: Boise, Idaho Posts: 561	PVC upgrade or inefficient? Hello all, New motor and yet another oil drip. The motor is fresh,5.7 negligible blow by. I now have drip coming from the driver rear oil pan area. (not above) Every Chevy i have owned has its drip and I can't stand it. Anyway,, I am going to pull and investigate. My feeling is I am still generating internal pressure that the PCV can not deal with at highway speeds. Are the TBI setups just not great at recovery? Should I add or upgrade the system? Is it the crank slinging oil on that spot? Any insight would be great. On my performance motors I just run two breathers to the air cleaner and never had a problem, those motors have much more blow by at 6,000 than my TBI CHris

09-05-2018, 02:55 PM	#2
SunSoaked Registered User Join Date: Dec 2011 Location: Yuma Arizona Posts: 1,526	Re: PVC upgrade or inefficient? Buy a Harley. You'll forget all about the Chevy. ...and lots of cat litter.

09-09-2018, 10:10 AM	#3
Pontiac1976 Registered User Join Date: Oct 2015 Location: Ottawa, Ontario, Canada Posts: 752	Re: PVC upgrade or inefficient? I assume it 85 up motor should be a one piece oil pan gasket. check bolts that they loosen off. Did you put a new rear main seal. Is the or pan gasket smooth flush at the mating areas, sum blocks the two main rear bolts on the pan need a little dab of silicone on the thread of the bolt because they go all the way throw in to the oil area some time leak. Make sure the silicone has time to dry before getting oil on them or driving. Not sure on the breathers as long as it's not clogged one side air coming in one side gases pulled out burned in the TBI or the older carb set up. __________________ 1977 REG cab Long Bed with a 1984 Front Clip, 82 305 .60 over 9.0.1 flat top pistons, 4bbl, TH350, w/84 SS-intake & cam , w/ 1977 big block rad, 1975 gear box, 1984 master w/ metric fittings top & SAE fitting @ portion block, 1975 3.42 gear open diff. Duel 77-87 Factory air cleaner, duel inlet from rad support . Down sized 9' to new 8' Steel flat bed Was a 77 454 w/308 gear. Taken out 550 lbs. up front with motor clip change.

09-09-2018, 11:07 AM	#4
chris989 Registered User Join Date: Dec 2011 Location: Boise, Idaho Posts: 561	Re: PVC upgrade or inefficient? Update, Pulled the pan and converter cover. It is not the oil galley plugs on the back of the block. It appears the leak was at the very rear corner of the pan, the gasket was a one piece and it had silicone in the corners. I replaced the gasket and PCV valve,, time will tell. The PCV valve was working but it did not flow as well as the new one so I am hoping it was the cause of my leak.

09-10-2018, 04:59 PM	#6
chris989 Registered User Join Date: Dec 2011 Location: Boise, Idaho Posts: 561	Re: PVC upgrade or inefficient? Chevrolet Performance PCV Valves 6487779



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