Porous Oil Pan!

[conipc]

Minor leak under the engine is NOT main seal or pan gasket. Diagnosed as an overly-porous pan: Tech cleaned everything, pressure testing found NO leaks, but he could see the pan essentially sweating oil! So, is the pan on a 4BW plastic, steel or alloy? In any case it's a major job to replace.

 

[bl4ck_wng]

Woah.... I have seen an aluminum pan sweat once before, the guy said it was related to the differing metals cooling at different rates after track use. Probably different than what is being described here

 

[jbawden]

I think the LF4 uses a cast aluminum oil pan. I don't think porosity issues are anything new with modern aluminum casting processes, at least with GM. My '07 V1 had an issue with a porous rear main cover which was a known issue for the LS2 at the time.

 

[Melon]

Here is an example of one on eBay.

Cadillac CTS ATS Oil Pan LF3 LF4 New OEM | eBay

2014-2017 Cadillac CTS Engine Oil Pan VIN 8 (8th digit, Option LF3 / LF4). 2016-2017 Cadillac ATS Engine Oil Pan, VIN Y (8th digit, Option LF4). This is a New OEM GM Oil Pan for the Cadillac ATS, Cadillac CTS with the 6 Cylinder 3.6L Engine.

www.ebay.com

I haven't heard of a porous modern aluminum oil pan, but they can develop small cracks that are hard to see with the eye. If it keeps leaking press them to swap it out under warranty. It could be a manufacturing defect or result of improper installation.

 

[conipc]

It's being changed out now under warranty. That is one complex casting! Not surprising there might be a bad spot in all that area and small corners..

 

[Melon]

It's being changed out now under warranty. That is one complex casting! Not surprising there might be a bad spot in all that area and small corners..

Yeah, I was surprised. I've cracked a pan once on an E36 M3 and fixed it with JB weld.

Glad they're taking care of you! Seems like a rare fluke.