Oil Leak Between Engine and Transmission...

[CIWS]

I know of another case of an STS-V having the lower crankcase seal replaced due to leaking outside of my area. So I'm not an only case, but let's certainly hope they are the exceptions.

[Fire and Ice]

From what I understand, it's common the case halves leak on the Northstar motors. If you notice some drops on the garage floor, get it taken care of right away, especially if the vehicle is under warranty.

[hodgeee1]

You know after looking closely at your pictures, it looks like the oil is coming from the crank. If you look, the filter is 90 degrees away from your oil buildup, plus you can see it coming down the pan. I don't know how the heck the filter 5" over and on another side could cause that oil leak, when you get your car back check it again please.

I don't want to say that they are just blowing you off, but it has known to happen, and again like I said it looks from the crank not the filter!

It isn't that hard for them to replace the seal, especially with how the block is setup on this car. The pan being a forged aluminum pan, its real easy to take off and put back on, so getting to that last endcap is pretty easy. I am pretty sure that it is a split seal that these engines use wich means they should be able replace them without having to pull the tranny or motor like on some cars!

[CIWS]

1st pic shown was the 2nd leak. That ended up being a front seal they didn't put back on correctly with sealant when they pulled the engine to replace the lower crankcase seal that was leaking, shown in the 2nd pic. (original leak)

[z06bigbird]

[quote=AERO1;1569885]I will know more of this situation once the dealer checks it out and lets me know exactly where the leak is coming from. I should know by tomorrow (Monday July 7) or Tuesday (July 8) and I hope they can trace the origin of the leak. I will keep this thread updated as soon as I know anything.

From talking to a Cadillac technician last week, he said oil leaks on the Northstar engines are common, which is just ridiculous for an engine like this.

Northstar engines (2000 and later) might leak oil after 50k miles, but that leak comes from the pan gasket. No solution other than to replace the pan gasket. Here is the problem: Gasket is made out of aluminum and is perhaps 3/8 of an inch thick. Gasket is also about 3/4 inch wide on each side. GM engineers designed a grove around the entire gasket (right in the middle of each side) and put a rubber seal in this tiny grove. After about 50k miles, this rubber seal will wear out. Tightening the bolts will not help. Replacing the gasket involves taking much of the suspension down.

Northstars in the mid 90s had a potential for an oil leak in their multi-piece block. Engine had to be removed to eliminate that problem. GM eventually came up with a good fix for that.