M1 0W40 Acrid odor at change

[dickwells]

Just changed the 0W40 out of my 02 Silverado with probably 2-3k on it since last fall. I noticed an acrid odor which I remembered from changing out the oil in a large tank which was used to soak phenolic tubes at a temp of about 350F. I had added one qt of M1 5W30 within the last couple of months. Just wondering if anyone else has smelled this. The motor has definitely not been overheated at all. TNX, RW

 

[BobFout]

How does the smell compare to fresh M1 0w40 or fresh M1 5w30. Most oil smells unpleasant. (Yes, I'm an oil sniffer)

 

[dickwells]

Yea, it smells much stronger than new oil. Either like it is starting to break down or I got some kind of interaction between the 0w40 and the other oil I mixed with it.

 

[BobFout]

I'm going to guess some kind of interaction.

What oil did you put in after the change?

 

[dickwells]

I refilled with the same thing, M1 0W40 and Pure 1 filter.

 

[BobFout]

Originally Posted By: dickwells
I refilled with the same thing, M1 0W40 and Pure 1 filter.


OK, I guess maybe sniff the oil after another 2K or 3K miles and see how it smells, assuming no other oils will be added.

 

[mechtech2]

Probably contaminants in the oil. Water and acids - maybe cooties that grow in there.
From oil mixing? Unlikely.

 

[gathermewool]

Probably not breaking down after so few miles, and I doubt it's an interaction.

 

[Steve S]

GRIII basestocks!!!