I own a 2009 C6 30K miles. I have owned this vehicle for 7 months.
I have noticed after a GM dealer oil change my oil still appears dark,or dirty. I this normal? 2 oil changes completed.

 

Do you have any idea (receipts) how often the oil was changed before you got the car?
The engine could be a little dirty inside and the new oil's detergent may be dissolving it. Or maybe the technician didn't let it drain real well and there was a little left in.
A little darker could be normal, but if it is as dark/black as when you took it in, go back and have them check it.

 

2 questions do you know what clean motor oil looks like? IE: mobil1 5w-30, is your dealer putting mobil 1 5w-30 synthentic in?

 

A few more questions: the car has 30K on the car, and you have had it seven months. How many miles have you put on the car, and what is the frequency of oil changes you are making, 3K miles, 5K, etc.?

I do think it's possible that whomever you bought it from didn't change the oil much, or at all. Did you happen to look at the oil dipstick when you bought the car? And if so, was it dirty then?

 

Send it to Blackstone Labs for analysis.

http://www.blackstone-labs.com/

 

Here the thing...in my opinion the average corvette owner will change his oil 1,500 miles. Problem is, it may take 6 months before the car does 1,500 miles. The owner however starts the car every other day for 15 minutes. therein lies the problem.This ie when your pride and joy runs dirty. A cold engine generates the most emissions contaminating the oil with corrosive byproducts that can break down oil. This can cause the discoloration. Also remember the detergents, anti foaming additives and friction modifiers can make the oil dark when new.

 

While I don't own a Vette yet... I do change my own oil and have since I first started driving.

It is impossible to get every last drop of the old oil out. It won't take long for the new oil to look black. You can't judge oil by it's color, the only way to be sure is to have it lab tested.

Assuming you don't have a shyster charging you for oil he never put in, I don't think you have anything to worry about.

 

The baffeled oil pans in corvettes require extended oil drain periods. About half hour. That hardly ever happens at the dealership where you get paid per job. Me being an ex chevy tech I know.
I can thus see about a half quart oil not being drained.

 

I had 43K miles on my 07Z when I sold it and the oil never looked dirty after an oil change. (dry sump car)

My 13 GS has 13K miles on it and when I get the car back from the dealer the oil is so clean, you can hardly see it. (Wet Sump car)

BTW: Both cars ran Mobil 1 full syn. The 13 uses their Dexos version.

 

I agree and I have another car that I use Mobil 1 on/in, and it is hard to read the dipstick the oil's so clear.

 

If the oil was not change out regularly, then it will cause the oil to go dirty on the fast side. The new oil is just doing what is supposed to do, and that is to clean the engine while protecting it.



Having said that, even with a dirty engine from someone not changing the oil when needed, the new oil should look clean for a few hundred miles, hence before it has enough time to start pulling off the old deposits. So if the motor oil is dirty right after the oil change, then they did not allow enough time for the old oil to fully drain out, or the oil that gets trapped in the oil cooler/accusump (if 12v vavled and you need to put the car into run mode to dump the oil out of it) was beyond filthy to start with.

In either case, would take the car back to dealer to have the oil changed again.


Also to note, the mobil 1 motor oil may have a long, long friction service life, but once the oil gets dirty (pulled about as much as it can from the motor), change the oil.

Also to note, the motor oil should be changed once a year as well (no matter the min mileage). The oil, also collects some other nastiest in a year from the motor as well.

 

You said, "after a GM dealer oil change", but you did not say if it was 30 miles ago, or 3,000 miles ago, and you have not added that info, even though everyone is asking.

If it has been just a couple hundred miles, or less, since they "changed" the oil, and it is near black, my bet is that it was not changed. Most of us on here have done oil changes for decades, I sure know I have. I have changed cars that had 20K on the oil. After a change, the oil was a near-clear honey color, and lasted for at least 500 miles. If your oil is dirty after just a hundred miles or so, I don't think there is any way it was changed. Very possible the job got shuffled around, and the original tech changed the filter, then someone else took over, and thought the oil, too, had been changed.

Whatever the scenario, I would be back at the dealer, like yesterday.

Do you have the oil analysis back yet?

 

I had mine changed , yes the dealer, and when I check it, it isn't as clear as my wife's car after a change but it uses 0-30 Mobil1 whereas the Vette uses 5-30 Mobil1. I have not looked at fresh Mobil1 5-30 to compare from the container, does it look a little darker??? The Camry has 16,000, the Vette 26,000.
It doesn't look dirty just darker
Thanks
NSF

 

mobile 1 oil only....

 

Trying to locate a competent Corvette repair shop in Tucson AZ.
Dealers are useless.