thebishman

So I'm at 4200 miles and starting about 500 miles ago when coming to a stop at a red light etc, I can smell a distinct 'hot oil' odor inside the cabin. This does not occur at all when the car is moving.

This is with the HVAC set on 'Auto' or with manual control, but using outside, not recirculated, air.

There is no oil being 'burned' that I can see as the exhaust tips are 'normal'; my oil level is stable; there is no oil spilt on the drivetrain components anywhere; (I checked this past weekend when I changed the engine oil), and lastly when stopped with the engine running and I open the hood, there is no obvious smell of 'hot oil' to be smelled anywhere within the engine compartment.

Anyone know of any TSBs regarding this, or is there a definitive answer?

There have been a few other owners mention this issue in passing, but its pissing me off enough that I thought a dedicated thread was in order.

I think this weekend I'll remove the S/C cover to inspect that area as well as the intake 'snorkel' as I've seen mention of the possibility of 'standing' oil in both places, although I can't see how an oil odor could migrate from these areas into the interior.

Any thoughts/comments appreciated.

Bish

C7/Z06 Man

Using a catch can?

408sbc

https://www.corvetteforum.com/forums...oil-smell.html

https://www.corvetteforum.com/forums...oil-smell.html

https://www.corvetteforum.com/forums...oil-smell.html

C7/Z06 Man

No oil smell from day one and I have run this car hard at the drag strip more than once. No catch can either. Also followed GMs break in procedure. OH, and for a heavy "steel" rotored car (CC rotors 22 lbs less rotating weight) its not slow.

Jpjr2016

I've got a hot gas smell in the cabin. Usually after lunch.


Sorry, could not resist.

thebishman

Thanks for the links, and I know that you and I had mentioned it in another thread. Just trying to see if there are more answers.

If there is oil inside the S/C housing and the intake tract I'm not seeing how that air/smell is making its way inside the cabin via the HVAC system. It absolutely does not do this when set to Recirc; only when fresh air is selected.

Bish

lgodom

Have you tried coming to a stop and quickly opening your hood to see if the smell is present?

408sbc

Here is my theory: First, all Z06's have this issue to some degree. The people who are not reporting it either have one of the luckier Z06's that is not ingesting the higher amount of oil into the SC plenum via the PCV system....or do not have the acute sense of smell that picks it up.....or a combination of both. Second, what I think is happening is that the aggressive aero at the rear of the car is causing the oiled-air laden exhaust from the induction to wrap around the car and make it to the fresh air intake which is below the drivers side windshield wiper. I do not think it is oil laden air from the engine compartment because there is a hood seal that separates the engine compartment from the cabin fresh air intake. This isn't an issue of "burning oil".....this is an issue of the intake air for the engine being drug through a chamber covered in oil (pooling in spots in most cases) giving the air an oily bath before entering the combustion process. This theory "fits" with the oil smell almost immediately going away when the car starts to move again, hence exhaust once again trailing the car and the cabin intake once again pulling in fresh air. It also explains why you won't smell it with the air conditioning off and the cabin recirc on since you are no longer pulling in air from the outside via the exterior vent. Bet I'm right.

Mr. Gizmo

Run red lights and don't stop, you shouldn't smell the hot oil odor inside the cabin. ---- couldn't resist.

do the basics first if you have not done so -- crawl under the car to see if any oil is dripping on the exhaust, or have you checked the engine bay if you had a recent oil change, and oil was spilled somewhere in the engine compartment.

davepl

Honestly probably as simple as a leaky gasket somewhere (per Mr. Gizmo).

If oil in the intake path is common, I'll repeat my theory that oil in the intake air causes detonation which causes timing retard which causes the engine to run hot which makes it pull timing, run hotter, rinse and repeat. I can't help but wonder if some of the people with "really bad" cases of trackitis aren't experiencing major blowby setting off this cascade.

lgodom

Dave, that's my point too. A gasket or seal can leak fumes without leaking fluid. I've experienced this on two cars. One was the rear intake gasket and the other was never found. No signs of oil ever appeared. Just a wiff of burned oil coming in through the vents. Just because there's a seal between the hood and the cowl doesn't guarantee that the scent of oil wouldn't enter the cabin through the vents. The reason the smell isn't there until slowing down or stopping is there is enough airflow through the engine compartment to carry away the fumes.

davepl

On my M3 I had an oil smell, but it was sort of a burnt oil smell. About once every six months I'd ever get a little 'puff' out the cowl, then nothing for a long time. The dealer could never find it.

Then, when they had to tear the motor down for a rod bearing recall, it magically went away. So similar to your story, except I was lucky enough that it went away on its own, sort of.

lgodom

It went away because they replaced the leaking gasket. This won't be an easy problem to trace as you mentioned.

Mad Dog 24

Your theory makes some sense. As with our car those with cans installed posted less to no smell of oil. Does that fit your theory? I also think the new car smell in the Vettes has a similar smell as oil vapors. The adhesives may be petroleum based.

3 Z06ZR1

But yours sounds like BS. No can no smell and lets see you prove your comments?

CONMAX

I have noticed the oil smell since my car was new. At first, I thought it may have been do to the dealer overfilling the sump during the 500 mi oil change.

I always notice this after a freeway drive and then slowing to a stop. I believe that this is simply because of less air speed over the car and through the venting system.

The installation of a catch can has eliminated the oil under the SC cover, but not the oil smell. This smell is similar to fresh oil like a spill or from the oil tank.

It is interesting that not all owners have reported this issue. Dealers can only find references to overfilling and will replace filters and clean things up, but it does not help.

If enough of us report this, eventually GM will do something about it. With all of the other reported issues, I am sure they have a long list, but this one may have a simpler fix that the overheating.

I have an A8 Z07 just as an FYI for those keeping track of the reports.

badhabit_wb

I wonder if it's just autos that have the smell or m7's too? Just a thought. If you remove the sc cover please post pics of the inside. Good luck finding the problem.

408sbc

The issue has be identified by both A8 and M7 owners.

badhabit_wb

Thanks.

thebishman

Yesterday I pulled into the garage, left the car running and quickly got out to inspect, aka smell around the whole engine bay. Couldn't smell anything at all.

I never noticed this at all until I did an oil change about 500 miles ago. The oil level is perfect.
There is no oil on the undercarriage of the car; I checked.
I did not spill oil when refilling the car.

Bish