How would I go about (or whom should I contact) getting a letter from the factory to explain the dangers of overfilling the oil. I need something to show the dealer who overfilled my C6 by 1 quart.
Thanks in advance. David

 

Try to find it in existing information on the net or in a publication, cuz' I doubt you will get it any other way.

 

Thanks, Cat

 

Dealer should be able to access this info thru GM computer. Reason I know: My oil change (done last week) receipt showed SEVEN quarts of Mobil1. I checked dipstick when I got home and it was above high end. Called dealer who had me bring it right in today. Ends up it was "only" 1/2 quart over which they drained. He showed me a printout from GM that stated non-z51 C6 = 5.5 quarts, z-51 = 6.5 quarts.
Good luck.

 

This is the first I have heard about 6.5 quarts for the Z51. Where does it explain that? What's different with the Z51 engine? Nothing that I know of.

?

 

I don't know if you'll be able to find someone to give you what you're looking for. The owners manual specifically states that if you are going to race your car, you should overfill the oil level by 1 quart. I don't know the reasoning for this but the engineers put that there for a reason. I realize that this does not apply to your situation, but I don't think it will hurt your car if it's overfilled for a short period of time. I do agree that they should not have done this and should fix it if you have not done so already. If you will continue having oil changes done for you, you should tell them beforehand to use 5.5qt of Mobil1 and if they don't do as you ask, you'll make them do it again untill it's right.

 

Probably the additional oil cooler on the Z51
M

 

Show the dealer page 5-15 of the owner's manual.

Notice: Do not add too much oil. If your engine has
so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, your engine could be damaged.

 

Furthermore, there is no harm done to your engine with the overfill. The extra quart is required to prevent oil starvation under high rpm/high G turns in a track situation. 4 or 5 thousand rpm during a long sweeping turn could/will pump all the oil up into the heads and the G forces prevent it from draining back to the pan fast enough. The engine is designed to handle the extra quart but does not require it for normal street use. This is why the new Z06 will have a dry sump.

 

I've changed the oil on my Z51 several times, and 5.5 quarts fill it up to the highest mark on the dipstick...whatever that means.

 

Thanks for the replies. The dealer fixed it yesterday. Drained all the oil, and then refilled it until it reached the proper mark on the "inaccurate" dipstick. I was sure to pick at him about this.

 

Went for an oil change at Kelly Chevrolet in South Florida and got four different opinions from mechanics and the service writer on how much oil to put in. The service manager didn't know...He had to look it up. What's surpising is they are a big Vette store.

 

The z51 and the c6 have the SAME engine oil requirments
Both motors have the extra engine oil cools
The z51 has a extra power steering cooler and a tranny cooler that the base does not have !