rponfick

Just returned from my dealer for my first "free" oil change. I stupidly paid for the first one (for a total of $218.46), months ago, and then was told I had four remaining for the first two years (now, I guess I need to get three in next year as car is one year old).

Anyway, in looking at the numbers on the receipt I signed (which I assume is what they charge GM), the amount for oil was shown as $4.56 a quart for a total of $31.92, which comes out to 7 quarts. Since I have the Z51 dry sump I understood the oil volume is about 9.5 quarts. Sticker on door indicates Mobil 1, 5/30 was used.

Surely there is not 2 quarts remaining in the system if you just do a regular draining? Can anyone shed light on this?

The other charges on the receipt were (I think) .6 hr. for labor at $29.46, and $6.02 for a filter, for a grand total of $67.40.

(In reviewing my first paid bill, which was for something called a flush, showed 10 quarts at $7.95 per quart, and $9.03 for the filter).

I'm confused. Ralph

rcooper

Change dealers, those guys don't have a clue.

hdrider1

Did you check the oil level in the dry sump per the procedure in the owners manual to make sure it was full after the oil change?

If they drained only the sump, but not the oil pan, then there could be 1.5 or so qts of old oil left in the pan, explaining why they only used 7 qts for the change.

The 9 qts on your 1st paid bill looks about right, but how did the total balloon to $218.49?

It would probably be worth at least a call to the dealer to inquire why only 7 qts were used -- you may get lucky and get a straight answer.

This is another example of why I learned to change my own oil on my dry sump.

rponfick

I did check the oil level when I got home, after letting it set for the suggested 5 min. wait. The dipstick showed the oil up about 1/2 way on the hatched area. Not sure if one quart is required to fill system (like in "regular" cars) if level is down the bottom of hatched area. I can't imagine a dealer not pulling both drain plugs, since they are close together.

The other charges that inflated first billing were engine flush for 1 hour at $77.00, and a BG105 oil flush thingy, for $39.95. Why the filter was more, I have no idea. And the oil was the Mobil true synthetic, verses the Dexos blend.

I may go back and talk to the dealer.

Ralph

bob guzzy

The most that should go in your car is 9 quarts, check your oil level as per the manual.

The hot oil level should be somewhere near the bottom of the hash marks, take the car for a ride to warm it up, shut it down and wait 10 min then check the oil.

Anymore than 9 qts. in your car can lead to oil ingestion.

KenHorse

Maybe it varies a bit car-to-car but I've found 9.5 quarts is perfect for mine

juststan

there is a new tsb for oil change on z51 only. it is on here some where

Glen e

It certainly varies on how you drive the car, a car driven aggressivly is going to burp more than a grocery getter. Whatever it takes, mid stick is the answer, not max full. You figure out what that is in quarts. Many dont drain fully, either.

rponfick

Another question I haven't raised is how quickly does oil temp rise. With a Z51, and the separate oil tank, how exposed is it to engine temperature. When I dropped off the car the oil temp was about 190. It took 1 1/2 hours for the oil change. When I drove off after the change, within a couple of miles (when I first looked at the gauge), I noticed the oil temp was again about 190 degrees. In the past, the oil temp has taken awhile to increase to reach engine temp., only after at least 15 miles.

You may see where I am going with this.

Ralph

mksz51

The "flush" they noted on the first bill - that's what they did to your wallet. Seriously - everyone needs to learn how to do this yourself OR find a trusted mechanic. I am gladly NOT using any of the "free" oil changes just to keep my car AWAY from the dealership. Have done the same thing with two Toyota vehicles (although I actually trust their service more and an oil change on a Toyota is certainly more "conventional" than a dry sump). In my opinion, for everything that Bowling Green "IS" most Chevrolet dealers are "NOT".

KenHorse

Yea, you're thinking they didn't change a great quantity of the oil?

Remember, the block is still warm, the heads are still warm and the coolant is still warm. That' going to contribute to the oil warming up faster than at a cold start...

C2367

It's not free, you paid for it in the price of the car.

yancruiser

I have a 2 month old C7 Z51 and I chose to proactively change my oil at 585 miles. I still plan to claim the Free GM Oil changes on schedule to have them look over other things, but I changed my oil early during break-in to both avoid as well as to inspect for trouble. Didn't find any, but the official amount of oil for Z51 seems to be 9.8 quarts. The picture is what came out along with whatever was stuck in the car and the filter. I put in 2 x 5 Quart jugs of Mobil 1 5W-30 Synthetic and I have around a half a quart left in the jug as my dip stick hits the high dot when warm.

Tom/99

To bad the free oil changes can't be used on other cars. I will never let the dealer change the oil in my car. You have no idea of how much, of what type of oil they really use.

JerryU

You may be correct on the pricing being what they could charge GM. Since they used Mobile 1, $4.56 would probably be the wholesale price and $6.02 for the filter the same. When I changed my own oil, since I could not find the correct AC filter at Walmart where I bought my oil (~$5 quart in 5 quart jugs but ~$7.50 quart in quart bottles, which is similar to AutoZone etc.) so bought the filter from the Chevy dealer and paid about $7.50. I was told that was a 33% discount since I said I wasn’t using the free service and could I get a discount (best they would do and not the typical mechanics discount of 50%!) If that is the charge to GM (surprised they showed that to you) sounds like GM allows only 0.6 hours for an oil and filter change in a Z51.
Guess they can’t charge for the time to fully drain, change filter, get the new oil hot and then the 5 to 10 minutes before checking I assume top off! One reason I changed my own oil since a technician on commission can’t make any money at that rate and I can’t see all of them looking at their watch and checking per the manual!
Note the Owner’s Manual for a 2007 Z06 says if you wait too long to check the hot oil level, the dry sump may show no oil on the dip stick since some drains back (assume thru the scavenge pump) to the pan! That is the reason for the "wait 5 mintues" (for it to drain from the baffels in the tank) and "no more than 10 minutes" (so a measurable amount doesn't drain back.)
Have no explanation for using only 7 quarts-GM must allow 10 for a Z51!?

yancruiser

I would definitely check and ask the dealer what grade you are actually getting. I believe the standard for Corvette is the non-Synthetic Mobil 1 5W-30. Tom/99, I am 67% agreement with you to not let the dealer change the oil, but we would also get service notifications as we bring the car in and a chance to talk to the service rep about other issues or concerns. I am planning to treat the free oil as an extra flush before I upgrade the oil to my liking.

Old buckeye

Just curious - you indicated the bill was for $218.46 with $79.95 for oil and $9.03 for the filter, so was wondering if they actually charged you $129.93 for labor and tax? I have read on this forum that some dealers will not even honor the free oil changes which seems odd.

FPS Hungary

I don't think "free" maintenance is worth anything when the people doing the maintenance didn't graduate elementary school.

Glen e

Quite a bad generalization.....

C7Joy

In my experience I think you're right. I changed my own and put in 9.5 and found it was too much. I drew about 1/2 quart out to drop my oil level about midway in the hash marks on the dipstick. I have checked it a couple times since the change, at temperature per manual, and it stays right where I set it.