Corvett4Ever

I parked my C7 in my new garage two days before and it was sitting there last two day and today I noticed black color oil marks on the floor. seems like it is coming from the rear end of the car. somewhere in between two rear wheels. I dont know exactly when this has started as my car was previously parked in a car port where the floor was very dirty and icy so hard to find any oil marks, but two days before I moved my car to this new garage and then noticed this oil marks in the floor.

I got my car around 3 months before and it has only 1200 miles on it. I didnt drove it much last few months because of the heavy snow conditions. Basically car was sitting in the car port almost all the time.

Is this something serious ? Should I immediately bring the car to the dealer ? The roads are very bad with the last snow storm and I was planing to wait till the roads get clear a bit.

here are some pictures

any idea ?

ArcticC7

Take a white Kleenex or paper towel and rub the spot to see what color the oil is. Also put a paper towel under the car in that spot overnight and see what you catch. Either way you are going to need to see Mr. Goodwrench make an appointment and ask for a rental car.

ZL-1

This is a condition that happened last winter to owners who drove their 2014 C7s in very cold weather. The differential axle seals were losing their resilience when very cold. One forum member who drove his C7 daily through the winter visited his dealer in Wheeling IL repeatedly last winter. They replaced the seals several times, then the differential, but that seal design just couldn't cope with the cold. Other cold weather C7 owners reported it too. Strangely usually the left side. It comes from up high enough that it doesn't seep enough oil to get really low, just an annoyance. Once the fluid level gets a bit lower the seepage diminishes. As of last spring GM was validation testing a new seal design to correct the issue, I'm guessing it might be in production by now. The situation went away last spring when it got warm but winter is here again. Not sure if there is a service bulletin or PI on this. One engineer mentioned that the seal was used on other GM models with no is issues but for some reason they can leak on C7s.



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kevingilmore

yep, my car and it still leaks when its below 20F, although i now park in
a heated garage at work, so it leaks less. There is still no fix, gm is stalling
for what really is a safety issue.

Yes left side only. Dealer trick is to put the rear end up on blocks about
6 inches and overfill the differential. Now i only have to fill the thing up
twice during the winter.

Get under the car and run your finger over the top of the leaf spring on both
sides. The half shafts spray the oil all over the place, which might be another
safety hazard because the oil gets on the mufflers.

kind of amazing that GM never actually tested these cars in low temperatures.
With the all season tires, its a great winter car otherwise.

GOLD72

Some of you might remember that the C5 generation had a number of left side diff seal leak problems. My 01Z had to have that seal replaced two or three times in my 50k miles of ownership. It had nothing to do with cold weather performance since I live in the greater Houston area. Never have had a problem with the 06Z in 49k miles or the ZR1 in over 25k miles. The 07 vert has over 35k miles with no leaks.

Vetteman Jack

I remember that as my '00 coupe had the leaking differential seals three times in 37K miles before they got it fixed.

OP - good luck getting this fixed. No way should the seal be leaking just because it is cold outside. Hopefully GM comes up with a solution. And yes, I would get the car to the dealer for a repair.

And to the one poster about testing the car in cold weather, I seriously doubt that GM did not do any testing of the C7 in colder climates. Not every car sold gets to spend its entire life in 80* temps. The C5 had similar problems with the rear differential seals and it was certainly tested in cold weather.

Corvett4Ever

So this is differential oil ?
Is it ok to drive the car when this is happening ? Dealership is like 3 miles away. Not sure I should drive.

Thanks.

Larry/car

Will not hurt a thing. Probably when component reaches operating temperatures the leak stops as seals expand. Put a drip pan under the leak and wait for warmer weather, then get it fixed.

Kracka

Put down down oil absorb stuff and don't worry about it until the weather clears so you can make it safely to the dealership, it won't hurt anything to just let it sit there

kevingilmore

its differential oil if the top of the leaf spring is wet.
i guess it could also be the actuator oil if you have a LSD.

thats more fluid than mine leaks.

once you get it to the dealer, prepare for agrivation, as there is
no fix. Changing the seals does nothing but waste time.

i have put about 10k miles on mine since the differential and seals
were replaced.

Corvett4Ever

Thanks for replying everyone!!

So you guys saying that I should wait till the cold temperature goes back to normal to drive the car? means should I wait till end of the winter to drive it to the dealership ?

eboggs_jkvl

They're saying that the seals suck when it gets too cold and oil leaks. When it warms up, you can drive it to the dealer. The leak is high on the case and you'll have plenty of oil for the rear to function.

Another plan is move down here and you won't have the leak at all!

Elmer

Corvett4Ever

Thanks eboggs_jkvl. Anyway moving to FL is not a bad idea so that I can drive it year around. It is a pain that you cannot drive your corvette around 4-5 months here in east coast. I mean you can drive but it is not soo fun

Corvett4Ever

Thanks everyone for your replies !!

op z

We had some very cold weather in KS yesterday and today I noticed a small leak as well in the same area. Mine is a 2014 vin 21817. Way to go GM.

Marcus Nakamura

Could this cause a burnt oil smell when I come to a stop at a stop light?

Gr8ful

There is a " Diff fluid level" light if the level gets to low. If it is the diff you will be OK until at least the light comes on.

Calif Vetteman

Had to have that done in my 03. That was the only time I used my extended warranty.

noel48

Last winter my C7 leaked on the right side,this year it was the left side.

bluvette2000

Some but probably not all of these leaks in the C5 were due to overfill and leakage from the vent on the upper left side. If over filled this was made worse by jacking up the front end or parking on an up slope. Also made worse by continuing to refill. Recently after jacking up the front of my C7 I noticed a few drops of dif fluid from exactly the same location. No repetition in last few months with car parked level. BTW I live in So Cal.

This was exactly the case with my C5. Not sure if some of these leaks may be of a similar nature in the C7, but it should be considered. A lot of C5 seals were replaced unnecessarily!