Impala Forums banner
1 - 8 of 8 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Looking for ideas to solve my leak. Had a messy leaking oil pan gasket. Changed it out and dried up the bulk of the leak. After new pan gasket install
and a test run the next day I had oil running down the oil pan in the rear main area. Figured I had messed up the gasket putting it in so pulled pan down again a month later. Gasket looked good as far as I could tell when I took it down. Installed a second new gasket. Let set while permatex setup. Filled with oil the next and took a test drive all was good. Let sit for couple hours and topped off oil. Still good. Next morning have oil puddle in same place as after 1st gasket install. Up on the jack tonight and oil running down the pan in the same area. No detectable leaks from above that I can see with the dye in the oil. I can lay under car after shutting off and watch oil slowly run down the pan and drip. Not sure where to turn next. Did not think it was a rear main seal as the flywheel housing is dry and I have no oil being flung around. Tired of working on this and getting frustrated. Looking for any ideas what I could be missing or if someone else has had same issue. 2008 3.9l engine 196,000 miles.
 

·
Registered
Joined
·
49 Posts
"Rear Main" area you are calling what?

Your rear crank seal(rear main) will be where the trans and engine meet, right under the throttle body pretty much.
 

·
Registered
Joined
·
2,092 Posts
I had one of my engine seals changed before too. I think the mechanic put too much oil in the engine and damaged a seal. Maybe have it checked out so you know exactly which seal is damaged?
 

·
Registered
Joined
·
73 Posts
Looking for ideas to solve my leak. Had a messy leaking oil pan gasket. Changed it out and dried up the bulk of the leak. After new pan gasket install
and a test run the next day I had oil running down the oil pan in the rear main area. Figured I had messed up the gasket putting it in so pulled pan down again a month later. Gasket looked good as far as I could tell when I took it down. Installed a second new gasket. Let set while permatex setup. Filled with oil the next and took a test drive all was good. Let sit for couple hours and topped off oil. Still good. Next morning have oil puddle in same place as after 1st gasket install. Up on the jack tonight and oil running down the pan in the same area. No detectable leaks from above that I can see with the dye in the oil. I can lay under car after shutting off and watch oil slowly run down the pan and drip. Not sure where to turn next. Did not think it was a rear main seal as the flywheel housing is dry and I have no oil being flung around. Tired of working on this and getting frustrated. Looking for any ideas what I could be missing or if someone else has had same issue. 2008 3.9l engine 196,000 miles.
Ok I have run into this several times on these vehicles when they come from other shops after a repair.

When you remove the oil pan they use RTV in the back to seal the pan. if you don't get ALL and I do mean ALL of the RTV off it will leak.

Also make sure you are putting in new RTV
I use the thin one of a set like this scraper. Works perfect.
Scraper - http://amzn.to/2BI1CHl

Here is the RTV I recommend. You can get it at a dealer as well. I don't care for permatex personally.
GM RTV - http://amzn.to/2BHrG5c

Here are the pictures of where the sealer will be an where you need to put the RTV sealer.
 

Attachments

·
Registered
Joined
·
5 Posts
Discussion Starter · #6 ·
I have actually had the pan off two times with the same leak when I was done. New gasket both times. Did clean thoroughly the old silicone out of the area highlighted on either side of the main bearing cap. I can even see where silicone oozes out when I installed the pan. Really beginning to wonder if I should have applied silicone to the main bearing cap curved area of the pan gasket.
 

·
Registered
Joined
·
3 Posts
Ok I have run into this several times on these vehicles when they come from other shops after a repair.

When you remove the oil pan they use RTV in the back to seal the pan. if you don't get ALL and I do mean ALL of the RTV off it will leak.

Also make sure you are putting in new RTV
I use the thin one of a set like this scraper. Works perfect.
Scraper - http://amzn.to/2BI1CHl

Here is the RTV I recommend. You can get it at a dealer as well. I don't care for permatex personally.
GM RTV - http://amzn.to/2BHrG5c

Here are the pictures of where the sealer will be an where you need to put the RTV sealer.
Is it possible the pan has a shape change or some reason these things leak again or finicky about not sealing great?
 

·
Registered
Joined
·
3 Posts
I have actually had the pan off two times with the same leak when I was done. New gasket both times. Did clean thoroughly the old silicone out of the area highlighted on either side of the main bearing cap. I can even see where silicone oozes out when I installed the pan. Really beginning to wonder if I should have applied silicone to the main bearing cap curved area of the pan gasket.
I am thinking the same thing.
 
1 - 8 of 8 Posts
Top