Thread: Oil Change Mystery

Good evening all. The last 2-3 oil changes I have noticed something interesting about my oil. I haven't figured out if the color is from the lighting in my garage or what. It appears as if my oil has a slight reddish tint to it while it is draining from the oil pan but also in my collection container. When i dip a clean paper towel in the oil it appears to be your commonly brown/dirty oil, but it definitely appears to have some sort of a reddish tint (really difficult to tell). The one thing I know for a fact is that the oil gives off a horrendous body odor type smell to it. Not like a rotten eggs smell but a nasty body odor smell. This is not something i have observed before (have owned the car for approx. 2 years.) I was using Valvoline full synthetic 5w-30 and now have switched over to Mobile 1 full synthetic 0w-30. I observed the smell with both brands of oil. I switched to the 0-30 because it helps with dry starts and reduces the tick in cold weather (live in Wisconsin).

No noticeable coolant loss, all other fluids look fine. I'm stumped. I thought about collecting a sample to send in to get analyzed but if it is something others have noticed or there is a solution/explanation then I won't spend the money on that.

Any thoughts? Drive a 2008 GP GXP. Roughly 126,000 miles on her.

Synthetic oil has always smelled different than regular dino oil if you ask me.

As for the color I'd blame it partly on the lighting, in the garage with certain type of bulbs I've seen the oil have a reddish tint. I run 5W30 syn in my 2012 Silverado and sometimes notice it.

It still can be worth while to send in an oil sample to blackstone for the small amount they charge you. It would be good to know the health of the motor. You really never know with these AFM/DoD motors, it's always possible it could show metal wear from the DoD Lifters or the camshafts that sometimes wipe out lobes.

It definitely would be nice to know the exact shape the motor is in but I would rather not pull it all apart because of how much of a pain that is. I can tell you I definitely take care of it (at least since i have had it). I don't really have lifter tick at all. No noticeable knocks. Gas mileage is consistently 22 mpg. When I changed the plugs and wires around 100,000 there was not excessive scorching or oil buildup. Even though i use full synthetic I don't go past 4000 miles without a change. People may gripe that I'm wasting money but whatever. I know it's good clean oil in her all the time. I watch the levels too since she does eat some oil with the infamous DOD/AFM.

I just can't get around what would cause that body odor smell in the used oil. I have always used synthetic, but that odor, at least from what I can remember has been with the last 2-3 changes. I did not notice it the year prior.

I'm thinking I will send in a sample of the oil. Maybe use some seafoam in the oil, for a very short duration as well. Every once in a while I will use it in the gas tank.

In the next month here I will be sending in my computer to Overkill for a tune. Get rid of that DOD/AFM plus the tranny benefits that will follow with their tune.

You for sure want to get the AFM tuned out; one of the best things I did to my GXP