Cherokee Nation

When I change my I remove the plug and go in and take a nap after two plus hrs all the old oil is out,I'm never in a hurry like the dealers or oil change places.

mkitt27

When I had my C6Z heads done last month I also had them change oil. Private shop. He was quite surprised how black and nasty the oil was. My selling dealer claims, even w/ paperwork, its was done just over a year ago and 3000 miles. My shop doesn't buy it. Maybe the dealer messed up by accident, or not... either way not pleased and less trustful than before.

Patsgarage

This.
I had a Grand Prix that I changed the oil every 3k on, the oil coming out looked almost as clean as the new oil going in. Oil should be changed while it is hot, this allows most of the contaminants to remain suspended in the oil when it is drained.
Diesel engines are a different story, I have to get used to the fact that the new oil in my Colorado is black before I back it out of the shop after an oil change.

jashmore1234

NY09C6

Some places simply let the oil drain for 2-3 min and close it back up. This is not enough to fully drain the system. Oil changes need to be done fast to keep them profitable, on top of that the pay of the tech is tied to their service volume. Customer satisfaction is highly tied to the amount of time the customer has to wait.

Rocky48

Am changing oil on my 1998 C5 today. Am 70 and never trusted anyone to change my oil
on any car. have heard the horror stories.

Rocky48

If new clean oil was put in, it should be clean an hour later. Do my own, but my C5 1998 was in
for Trans leak ( No Happy ) at dealership. Oil change quote was $105.87 plus tax. Included new oil plug.
Plug seals are built into the plug.

Welker1

Oil should look close to as it does freshly going in for at least the first few hundred miles, when mine is changed at 20% it is still fairly translucent. IMO, if it is black after just a few miles it is due to one of three things: Oil was not changed (which I doubt is the case at a dealership), the oil filter wasn't changed or the oil hadn't been changed previously for an extremely long period.

Rich Farr

I very much appreciate the comments. My conclusion is that the old oil was not fully drained and quickly mixed with the new oil. My Cadillac CTS and Corvette oil changes were the same afternoon. My son took the Cadillac in and drove about 10 miles before we had a chance to compare the oil from both cars by wiping clean dipsticks onto paper towels. The synthetic from the CTS barely showed any color at all. The Corvette was a medium brown. When I have checked the oil immediately after a change with the Corvette it always looked like the oil in the CTS.

I am 66 and used to do all my own auto repair. As I am still working and have a business to run, I no longer do my own auto maintenance. Until yesterday I never concerned myself about the cost of oil changes as the bills were always reasonable.

mhatton222

I change my own one per year with Mobil 1 synthetic and Mobil 1 filter. (costs me about $35.00) It comes out of the Mobil 1 bottle looking like honey. After a year it is black but after 1/2 mile??

Also depends on what oil your dealer is using. I watched an oil change video on Youtube for a Jeep Wrangler (my DD) and the guy used Royal Purple oil and it came out of the bottle black as night. I would not use Royal Purple myself after that video for sure.

Bruze

IIRC, Harley Davidson branded oil was also pretty black right out of the bottle. It did seem a bit odd, but I started using synthetics after they became popular for no reason other than they are superior lubricants.

dr_gallup

Curious if you have a GS coupe with M6 trans? If so then you have a dry sump engine with 10.5 quarts of oil and a large air-to-oil cooler. If they did not get the oil cooler drained then that would be a fair amount of old oil still in the system. Also the large quantity of oil would account for some of the high cost.

Bruze

In post #7 he said it's a base.

windyC6

On our regular car/truck I call oil starting to get dirty when I start having to look a little harder to read the dip stick through it. When you can't read it anymore it's dirty enough to be changed but may have a few more miles on it. I change the vette oil every 2 years (bout 5-7-K total miles) whether it needs it or not and you can still read the stick pretty well........

Jstan2014

Don-Vette

If you had the oil changed and oil still looks dirty, your engine is probably filled with sludge from poor maintenance. IMO