Inari

I have a 2006 Uplander with a 3.5l engine. I use it mostly to carry my tools and equipment when I go to work, or to travel between jobs. I live in a small city and most days I probably don't drive far enough to get the engine fully hot, although for the last couple of days I drove about 30 km each. I tend to be a hypochondriac when it comes to my vehicle.

Today I checked the oil, along with the other fluids. When I looked at my rag after cleaning my dipstick, I noticed the oil had a reddish tinge to it. I also noticed the that the inside of the oil cap had also turned reddish. I have never seen this before. What would cause it? Is it anything that needs fixing or otherwise worry about? The transmission fluid looks almost pristine, ditto for my pink coolant fluid. The fluids are all at the full level, and there is no sign of water on the dipstick or oil cap. There are no mechanical symptoms, and the temperature gauge is reading completely normal.

I looked at the dipstick from a friends vehicle and it looks like the normal brownish colour, although he travels many more miles for each trip than I do.

Thanks in advance,

Inari

oilcanhenry

Do you do your own oil changes? Never seen red motor oil.

Inari

Why do you ask? For 20 years I did my own oil changes. Now I live in an apartment and don't have anywhere to do it. I also can't do much of the routine maintenance specified in the user manual, or do an electronics diagnosis. By getting a garage to do this stuff I can find out what they are like before I need anything major done. (I now know to stay away from the local dealership or auto wreckers. One of them told me about leaks that weren't there. The other told me that my pristine brake fluid needed changing.)

That being said, I check the fluids from time to time. In this case found reddish crank case oil. Since posting this, I've been looking elsewhere on the internet to find out about oil colours. From the websites I've looked at the only bad colours seem to be white, creamy-yellow and milk-coffee.

At least one website showed me that synthetic oils become a sooty brown in the crankcase, while conventional oils become a reddish brown. For the past 25 years, I've had only synthetic put in my vehicle. This makes me wonder if the latest mechanic ripped me off by using a cheaper oil? Apparently, they don't carry synthetic oil in their shop so I had to bring my own. (!!!!) In this case it was Quaker State Gen2 Dexos. (They also forgot to lube all the fixtures, and charged me $7,00 to dispose of the oil and $7.00 for shop supplies!)

And then someone who is apparently an oil company engineer answered my question on Quora. He told me the "synthetic sooty brown vs the conventional reddish brown information" is "rubbish".

I'm pretty sure that someone on the Chevy Forum, somewhere, has the pertinent information that will clear up these mysteries. At least now I know the colour of the oil in my crankcase probably doesn't indicate any problems, and I can rest easy.

Cheers,
Inari

oilcanhenry

Royal Purple looks purple, not at all red. I don't know every oil that is on the market, but only ATF and some synchronizer fluids for transmissions and newer transfer cases are reddish. I used to sell such fluids and not once have I seen a red motor oil no matter if it was piston-powered aircraft motor oil even. I hope you don't have automatic transmission oil in your motor. ATF is a straight 10 weight fluid and has none of the requirements for any motor in a car or truck engine.

mountainmanjoe

dexcool is orange

Inari

The oil in my van is a reddish brown, not a straight red. Yes, I am familiar with Royal Purple. I put it in an old Ford Ranger I used to own. From the information I saw online, apparently some conventional engine oils start out as an amber colour with a red tinge, which turns to a dark brown with a reddish tinge as it gets depleted. Here are some of the links:

https://shop.advanceautoparts.com/r/...il-color-means

https://carbuyerlabs.com/the-color-o...pay-attention/

https://www.carcareinfo.com/what-col...engine-oil-be/

https://commons.wikimedia.org/wiki/F..._motor_oil.jpg
I just clicked on this link. It shows Mobil 1 Synthetic that interestingly enough appears to have a reddish tinge to it.


I was worried that some transmission fluid might have gotten into the crank case. Is there a place in the Uplander where there is a thin wall between the two fluids?

I look forward to reading more,

Inari