: Seeping Oil Pan Gasket

01-09-10, 08:54 AM
Brought the Caddy I picked up at Thanksgiving to "my" mechanic for the first time. He is really good, works on my Nissan, Chevy Truck, and Dodge Durango as well as my former cars. Very fair and has never tried to rip me off. He told me the only thing he could find wrong ( I asked him to do a once over on the vehicle) was that the oil pan gasket was seeping oil. He gave me an estimate of around $500 to replace it, but he told me if it was his car he would just add some oil "stop-leak" or "gasket conditioner" and that should take care of it. Thought I would check with group for their opinion. After reading all of the N* issues, I would make sure that I was doing anything obviously stupid (learned at least that in my advancing age!). Specific product recommendations very welcome if appropriate. This forum is fantastic so far (the Durango forum is like a bunch of ADD monkeys pounding keys and pressing the post button). I did try and search but could find nothing appropriate. Thanks in advance!!!!

01-09-10, 09:24 AM
The seeping pan gasket seems to be fairly common in Northstars. Some have had a little luck with a tweak at the pan bolts which are accessible with the engine up on the cradle - some bolts are hidden - and some have found that the oil level sensor tends to leak: that's a $25 fix at your next oil change. Piece of cake. If the oil pressure sensor is dripping, that's also a cheap fix, but a bit more labor-intensive.

I'm not a fan of stop-leaks and magic potions in oil. Plug up one thing and what else gets plugged up ?? A "weep" - a couple of drops a day - is nothing to worry about. A couple of carpet sample mats from your local floor covering store takes care of the drip..........

01-09-10, 09:28 AM
Thanks for the input. If I recall most of the oil stop leaks just soften the gaskets and cause them to swell a bit. Like you say, not a big deal.

01-10-10, 02:10 AM
AT-205 is what my auto shop instructor has us use on stuff like that... And yeah, it just softens the gaskets and makes them expand a little.

01-10-10, 09:12 AM
Don't forget that the "gasket" in the oil pan on these critters is NOT your old fiber stamping - it's a silicone formed seal "ring" which operates like an O-ring in that clamping pressure forces the material into a pre-machined groove. There is no "gasket material" to swell up and re-seal. (The half case has no gasket, either, because it's actually the entire lower main bearing cap, so the torque and clearance are critical.)

FWIW the gasket replacement on my 2002 calls for 13.7 hours of labor because the powertrain has to come out of the vehicle, and the oil pan seal is not just that: there's also the lower oil distribution plate/manifold to be resealed. From watching just the engine/oil pan part of this drill in a shop last year, it ain't fun.

01-10-10, 10:01 PM
I had luck with my 05 DTS, by removing the pan bolt I could reach and putting some thread sealer on them and re-tighten, found many loose even on the case halfs. Also found intake bolts loose and valve cover bolts loose. Now I have a very clean engine bottom and may have prevent a air leak on the intake. 93,000 mi on her and running strong.

01-10-10, 10:02 PM
But the AT-205 stuff is for silicone gaskets. It also softens the rubber/silicone valve stem seals which on some vehicles tend to harden from heat and go bad.

I don't know, it may just be snake oil. All I'm saying is that my instructor had us use it.

01-10-10, 10:06 PM
Thanks all. Definitely try the AT-205 on old beater Durango that I have. Probably take the wait and see on the Caddy