Oil Leak Again!

[Austin83]

My 2008 GMC Sierra is leaking oil now for the third time. At 4,000 miles the previous owner had the oil pan gasket replaced, at 6,000 miles I had a small oil leak, and the local GMC dealership replaced any gaskets that might contribute to the leak, and now at 10,000 it's started again. It isn't leaking bad, but a truck with 10,000 miles shouldn't have visible oil around the bell housing. The local Chevrolet dealership said they will work on it this time. Oil leaks have always bothered me, and it's even more painful on a great truck. I'm wondering if there is a burr or something wrong with the surface that the gasket is against. I told the Chevy dealership about my problems and he assured me it would be taken care of. What a whippin'!

 

Austin

[mattymax]

Oil leaks really bother me too!!! Nothing worse then parking on your driveway and worrying about oil dripping

 

I hope they are able to resolve it

[Eddie 70]

Is it trans fluid or oil? At the rear of the block could be the trans leaking. Mine was leaking at the trans pump or that is what they said. It was replaced by the local GMC Dealer and I have been leak free since.

[pm26]

It can also be the dreaded rear main oil seal leak.

[Austin83]

It is motor oil, and I believe the rear main seal was replaced the last time along with the another gasket or two. That doesn't mean it was done right though. Who knows, I'll let everyone know what I find out tomorrow.

[pm26]

At least you have it covered under warranty. My Nissan truck rear main oil seal leaking at 90K miles cost me over a grand to fix. (It also ruined the clutch disc).

[mattymax]

I always wonder if all this Synthetic is really good. Im a true believer in synthetic but you have to wonder if regular oil every 3K is better for the seals.

[Austin83]

I always wonder if all this Synthetic is really good. Im a true believer in synthetic but you have to wonder if regular oil every 3K is better for the seals.

 

I've wondered that too. I changed the oil at 7,000 miles and used Mobil 1 synthetic and a Mobil 1 filter.

[DaveH71]

I really doubt its the synthetic oil causing the leak. I've never had problems with synthetic and Id rather go with an oil thats engineered for the job of being in the engine vs something pumped out of the ground and refined. Redline oil has never done me wrong.

[pm26]

What I heard was that if your seals are really old and you have been using regular oil all along, it is not a good idea to switch to synthetic as it may cause the old seals to leak. However, this is just a rumor and debatable.

 

BTW, I use regular Castrol GTX oil and change in every 3k in all of my vehicles.

[mattymax]

Yea I have heard alot about Synthetic. You can literally read all day different opinions on the stuff.

 

I doubt AustinH's issue is due to the Mobil 1 at all. I was just thinking outloud for when these engines get older.

[Austin83]

Yea I have heard alot about Synthetic. You can literally read all day different opinions on the stuff.

 

I doubt AustinH's issue is due to the Mobil 1 at all. I was just thinking outloud for when these engines get older.

 

I don't blame synthetic at all on my issue, but I wouldn't run synethetic in my 93 Jeep Wrangler!

[Detroitboy]

What I heard was that if your seals are really old and you have been using regular oil all along, it is not a good idea to switch to synthetic as it may cause the old seals to leak. However, this is just a rumor and debatable.

 

BTW, I use regular Castrol GTX oil and change in every 3k in all of my vehicles.

 

Its true. I switched to synthetic in my beater DD (a low milage plymouth breeze) and it started leaking from the rear main pretty bad. I switched back to regular oil and the problem stopped. I'm sure it depends on the year of the vehicle and general condition of seals.

But I had a big oil consumption/smoking problem in my 24 HP honda powered riding mower when I switched to synthetic too. It went away instantly with regular oil.

[RyanbabZ71]

Does the leak cause any puddles/wet spots on the driveway or garage floor?

[Stevens03]

On my 2007, they replaced the rear main twice. The first time,... dealership admitted once the seal was out, they did it wrong the first time.