Oil Leak problems. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

71GMC71 · 08-11-2010, 02:12 PM

I'm starting to work on my truck more since im out of school and ive had this oil leak forever now.

But me and my dad decided to try to fix it so i can park in the driveway.

We changed the front and back main seals. Because my dad thought that was the problem. But i am still leaking oil. And alot. I have to get oil about every week for my truck and its burning a whole in my pocket. We just cant figure out how to fix the problem. Any suggestions?

**john** · 08-11-2010, 02:46 PM

It would be hard to say without knowing which engine you are working on.

cdowns · 08-11-2010, 03:20 PM

where do you see a leak puddle when parked?

1968CHEVYC10 · 08-11-2010, 03:54 PM

It could be the oil pan, also check the distributor gasket, oil pressure sending line, and around the dipstick where it meets the block.

71GMC71 · 08-11-2010, 04:15 PM

Sorry.

Engines a 350, and we replaced the oil pan gaskets.

71GMC71 · 08-11-2010, 04:15 PM

Quote:

Originally Posted by cdowns

where do you see a leak puddle when parked?

Right under the oil and main seal. Just little droplets around/

marcsRX · 08-11-2010, 04:16 PM

I had a leaking issue my self. Do whats cheap first.

I thought it was a rear main seal, and probably was.

What i did was to change the entire breather system, PVC and all related vents. Solved my issue.

If you have positive crank pressure, oil will seep out where ever it can.

1968CHEVYC10 · 08-11-2010, 04:55 PM

Quote:

Originally Posted by 71GMC71

Sorry.

Engines a 350, and we replaced the oil pan gaskets.

It could still be the oil pan, I just did mt rear main and oil pan, The rear main leak was stopped but it took a few extra tightening to get the pan to stop leaking.

bradley7576 · 08-15-2010, 12:10 AM

check the back of the intake manifold

GASoline71 · 08-15-2010, 12:56 AM

Also check the valve covers. SBC valve covers are a horrible design, and are prone to leak over time.

They should have been designed with a bolt at each end too...

Gary

71GMC71 · 08-15-2010, 01:52 AM

Quote:

Originally Posted by bradley7576

check the back of the intake manifold

Quote:

Originally Posted by GASoline71

Also check the valve covers. SBC valve covers are a horrible design, and are prone to leak over time.

They should have been designed with a bolt at each end too...

Gary

We have a new manifold but we need a new carb. Preferably a holley 600 but my dad doesn't wanna pay 300 for a brand new one.

And ive changed the valve cover gaskets 3 times now!

Irishpilot · 08-15-2010, 06:16 AM

I agree with marcsRX, check your PVC valve and tubing. I also run a breather on the other side. I used to run a breather on each side, but was having bad blow-by above 4000 rpm. The PVC fixed it.

**leddzepp** · 08-15-2010, 12:07 PM

First question: Do you have PCV?

There is no reason to have to change valve cover gaskets three times. Buy the perma seal plus ones from Fel-Pro. Torque to 7 ft lbs. Bye bye leaking valve covers. If your oil pan is still leaking, also use the fel-pro one piece. It is rubber and will cure a leak if you have one there. If these are not the problem, check all other small areas as mentioned above.

bradley7576 · 08-15-2010, 07:50 PM

do you have the wing nut on the valve covers? that help transfer pressure to the back and front of the valve covers.

08-11-2010, 02:12 PM	#1
71GMC71 Registered User Join Date: Apr 2010 Location: Moreno Valley Posts: 74	Oil Leak problems. I'm starting to work on my truck more since im out of school and ive had this oil leak forever now. But me and my dad decided to try to fix it so i can park in the driveway. We changed the front and back main seals. Because my dad thought that was the problem. But i am still leaking oil. And alot. I have to get oil about every week for my truck and its burning a whole in my pocket. We just cant figure out how to fix the problem. Any suggestions? __________________ ~~'71 GMC shortbed. Recently, 2007 Mazda 3 hatchback.

08-11-2010, 02:46 PM	#2
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	Re: Oil Leak problems. It would be hard to say without knowing which engine you are working on. __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/

08-11-2010, 03:20 PM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Oil Leak problems. where do you see a leak puddle when parked? __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

08-11-2010, 03:54 PM	#4
1968CHEVYC10 Registered User Join Date: Aug 2009 Location: Tomball, TX Posts: 578	Re: Oil Leak problems. It could be the oil pan, also check the distributor gasket, oil pressure sending line, and around the dipstick where it meets the block. __________________ '68 C10 LWB 6.2NA/NP833 3.73's

08-11-2010, 04:15 PM	#5
71GMC71 Registered User Join Date: Apr 2010 Location: Moreno Valley Posts: 74	Re: Oil Leak problems. Sorry. Engines a 350, and we replaced the oil pan gaskets. __________________ ~~'71 GMC shortbed. Recently, 2007 Mazda 3 hatchback.

08-11-2010, 04:16 PM	#7
marcsRX 68 C10 SWB Join Date: Nov 2009 Location: Chicago Posts: 216	Re: Oil Leak problems. I had a leaking issue my self. Do whats cheap first. I thought it was a rear main seal, and probably was. What i did was to change the entire breather system, PVC and all related vents. Solved my issue. If you have positive crank pressure, oil will seep out where ever it can. __________________ "How much physical pain do you go through on a daily basis that you can directly attribute to your lack of intelligence?" -R0bman

08-15-2010, 12:10 AM	#9
bradley7576 Registered User Join Date: Jun 2010 Location: Dallas, texas Posts: 51	Re: Oil Leak problems. check the back of the intake manifold

08-15-2010, 06:16 AM	#12
Irishpilot Registered User Join Date: Jul 2006 Location: Kunsan AB, South Korea Posts: 187	Re: Oil Leak problems. I agree with marcsRX, check your PVC valve and tubing. I also run a breather on the other side. I used to run a breather on each side, but was having bad blow-by above 4000 rpm. The PVC fixed it.

08-15-2010, 12:07 PM	#13
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 19,996	Re: Oil Leak problems. First question: Do you have PCV? There is no reason to have to change valve cover gaskets three times. Buy the perma seal plus ones from Fel-Pro. Torque to 7 ft lbs. Bye bye leaking valve covers. If your oil pan is still leaking, also use the fel-pro one piece. It is rubber and will cure a leak if you have one there. If these are not the problem, check all other small areas as mentioned above. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man

08-15-2010, 07:50 PM	#14
bradley7576 Registered User Join Date: Jun 2010 Location: Dallas, texas Posts: 51	Re: Oil Leak problems. do you have the wing nut on the valve covers? that help transfer pressure to the back and front of the valve covers.

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