Tracking down an oil leak...

Drivetrain discussion including Transmission, Differential, Driveshaft, and related items.
Post Reply
KD9GVS
Posts: 4
Joined: Thu Feb 28, 2019 12:06 am

Tracking down an oil leak...

Post by KD9GVS »

Newbie from Wisconsin here...love my 2011 9C1, runs great, no issues except unfortunately it suffers from a significant oil leak around bell housing area. Oil dripping from lower bell housing area near starter motor, also coming from somewhere on upper side of bell housing. Of course the first thought is rear main seal, but not 100% confirmed. Out of curiosity I stopped by a local GM dealer and they told me they would drop entire K- member (?) vs. removal of transmission by itself in order to replace RMS. Sounded excessive to me, seems tranny removal gains access to that rear cover. Any thoughts out there greatly appreciated. Labor was quoted in the 800$ range for this work.
smwalker
Administration Staff
Posts: 2201
Joined: Mon Jul 29, 2013 1:44 am
Location: Azusa,CA

Re: Tracking down an oil leak...

Post by smwalker »

Although it's super hard to see - grab a light and look at the oil pressure switch at the back of the engine/throttle body. That sometimes drips down and looks like a rear main seal.

OIl Pressure Sensor is the one with the gray cap:
Image
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
Sanford
Posts: 356
Joined: Mon Dec 12, 2016 9:38 pm
Location: Texas Gulf Coast

Re: Tracking down an oil leak...

Post by Sanford »

I second the oil pressure switch as a possible culprit. With the Teflon seals they use, the failure rate should be fairly lower.

I would pull trans before I would drop the cradle. The first car I bought had engine damage which required me to pull the engine and trans as an assembly. I did not want to reinstall as one assembly, so I stabbed the trans after the engine was in. I have a trans jack so it did not make it to hard install. If you pull the wiper arms of and remove the plastic cowl, the top bell housing bolts are a piece of cake to get to.

David
KD9GVS
Posts: 4
Joined: Thu Feb 28, 2019 12:06 am

Re: Tracking down an oil leak...

Post by KD9GVS »

Thanks Steve and David for the replies. I managed to find that oil pressure switch at the back of the intake, and watched that area with an inspection camera while vehicle running. No obvious leaks were seen there. Entire bell housing areas that I could see are wet with a coat of oil, with a steady drip while running. Nothing obvious "higher" than that. Everything seems to be pointing to the RMS as the culprit.

Rick
Post Reply