Exhaust smell in cabin
 

Just purchased a 2017 Grand Sport convertible. There is, what I think, an exhaust smell in the cabin. Has anyone had this? I could use your help. Thanks

What trim level is yours?

I only ask because sometimes the "new car" smell is pretty potent, but seems to be less "chemical/petroleum" the "higher" you go, and more "leather-like."

2lt

Second owner...?

Check your clamps. If that doesn't do it, take it to the dealer.

Yes 2nd owner

Were there any mods to the exhaust system, extensive warranty work, or accidents?

I picked up my 2017 GS 2LT on 2/1/17. It's stored in a garage with the windows up. To this day, when you get in there is still an adhesive/chemical smell. During delivery, when the sales guy gave an extensive ~3 hour orientation, I thought I was getting gassed. The smell is lessening over time. I guess I should leave the windows open more but I hate to let dust and dirt in.

Let just say the recirculation vs. outside air function on this car is the worst ever!! Not sure why but I have found absolutely no way to cut off or reduce outside smells at will .... ever in this car....

You might want to find out what happened to the first owner.... :(

Rick, could have been TUNED by the first owner; does it have that perfume smell when you're sitting at idle? Dale

The owner found out that he was losing his vision. Sold it with only 2,300 miles on it

I’m going to the dealership on Tuesday. Will have them check it out

Thanks everyone

Might be from a recent oil change. These cars seem to channel a burnt oil smell thru the AC system.

:iagree: One possible way that can happen is a "mechanics helper" working the oil change bay doing few dry sumps. It is also IMO why some other dry sump issues occur such as overfill or not using Mobil 1.

99+% of the cars/trucks getting oil change service only require dexos approved oil. That is what is often in the oil change bay and with good mechanics hard to find a newbie may be working the oil change bay.

The easy thing for the person working the service bay to do is pump oil from the 55 gallon drum in the bay. The alternative for a Vette, is for them to go to the parts department, sign out for and carry 10 quarts of Mobil 1 back to the bay.

If they take the easy way out and pump from the drum they just pull the trigger on the fill gun. On a wet sump they can just pull the level fully and get max flow. There is essentially a bottomless pit under the oil fill neck! Do that in a dry sump and oil will quickly spill out the oil fill hole! There are baffles in the dry sump tank and oil must be introduced slowly. (I do my own oil changes and pour the oil slowly. To be sure there are no spills I put a large rag around the filler neck.)

The dry sump tank is next to the engine firewall. The filler cap is on the back side of the tank. If oil spills, it is relatively easy to clean the front and sides of the tank. The back not so easy as there is little room. On the firewall, behind the tank is the cover for the cabin air filter. It is a "flimsy" plastic cover not having a great seal. As the engine oil heats, it heats the tank and will increase the vapor from the spilled oil. The vapor can go past the cabin air filter cover seal and enter the car.

A number of reports of the smell occurring after an oil change and going away in a few weeks. I suspect after the spilled oil has all evaporated. There are other possible areas for an oil spill but I have done all my own oil changes in my 2014 Z51 and Grand Sport have never smelled oil. There has not been any oil spilled!

Just Sayn'. Could check the tank behind the oil fill neck.

Are you really sure it's exhaust fumes? One sure way to tell would be to put a carbon monoxide detector in the car. It should go crazy from fresh exhaust fumes, but not from most other things.

Put it in the car for a while before you start the engine. If being in the car with the engine not running doesn't set it off, then start the engine, and drive for a while like you normally do. If you get an alarm, put the windows down immediately.

You don't say if the smell is with the top up or down, at least I didn't see such. Also, you might, like I did, find it interesting that one of the questions on the Owner Survey GM sent me for my '18 I got in September was what I thought of the SMELL of the interior. I've never ever seen such before on a factory survey. The point is... there may be more, or have been more going on with odor than we "unwashed" are aware of.

Did you ever find out what was causing the exhaust smell? I'm experiencing similar on my 2016 Convertible.

Yes, The seal between the engine and the tranny has a seal that while it does not leak, there is a smell from it. Apparently has something to do with the adhesive that was used at the factory. The dealer put in a new seal with different adhesive and the smell went away.

There isn't a recall, but the is a TSB on this very problem. Sorry I don't have the TSB number anymore but you dealer should be able to help.

By tightening the nuts on the oil cooler system, were you able to get the smell to stop? I have 2016 Z51 and have had oil smell in cabin since first filter change mainly when I stop I pick it up in the cabin. I am TQ ing filter to 18 foot pounds now.

Second question did you take the car in for service to have issue corrected. If so did the smell go away and what service did they actually perform.

Best Regards Walter Minnicks
Walter,

after snuggling up those bolts, I have not seen any additional leaking and the smell has completely abated. I’m confident that was the issue. I still took it to the dealer about a week later since I had already made the appointment to have them look at it and make sure there was no other issue I was missing (ie common gasket failures,etc). They said it all looked good and we are going to coming ie to monitor it. But so far, no other issues. Do you happen to see any oil on the undercarriage?

Joe
It has been a few week weeks, I did tighten oil cooler bolts they were 1/4 turn loose and tightening, checked mating surfaces with blue light no oil noted. Tightened bolts on cooler added 1/2 turn to all those. One thing I did not there was a light oil staining on bell housing lower left side corner cleaned all surfaces of the cooler with brake clean and drove 10 miles, came back and still had slight smell from under car drivers door.

Was reading a posting and notice some people mentioning loose oil pressure send unit. I sprayed the back of the engine down with brake clean let dry for awhile drove 10 miles very little oil smell then. Ordered new valve cover gaskets for replacement and will remove other top hardware to access oil sensor for slight leakage from. Will keep you updated.
Thanks for the update. Let me know if you find anything interesting when you do the swap. I haven’t had mine back on a lift since I tightened everything, but I haven’t had any of the smell back either. I’ll check it out real close when I change the oil next.

Joe 3/8/2020

FYI
Okay here goes, did tighten the bolts on the dry sump oil cooler mounting flange(2) bolts to the block, and also the finned oil cooler unit bolts this seemed to stop smell coming from that area (good). Went to order new gasket and on Ebay found many companies offer the metal gasket, which makes me think this must be a common issue, going to wait for a little warmer weather to replace gasket to complete that task.

Second, I was still getting a little oil smell after securing cooler flange bolts, I worked in the aircraft biz for 36 years, and one night recently a thought came to me to check all the vent lines to and from oil sump can and other engine connections. Doing this this proved valuable info,one line the right line from the top of the sump can was totally block internally. How I found this out, I applied 100 psi I air to all the sump lines, I found the right side line/adapter there was a very high pitch whistle at the plastic intake manifold adapter point. After applying air several times what ever was in there went away and so far has my oil smell issue. Did pull 90 degree bend on air intake and checked for blockage a both points which was found clear. I have had a issue with this for 3 years now, I did the work because I do not like the dealership really working on my car, beside that my corvette has been one hell of an excellent car.

The car was brought to the dealer numerous times. I started doing some hunting around and found a TSB that addressed the problem. There was no leaking anywhere, just a smell when you came to a stoplight . They had to crack the seal between the engine and transmission and replace that seal with some different adhesive. Problem gone and did not come back. I'm that I didn't keep the TSB, but this was a couple of years ago. I do remember that they had the same problems with other Chevys and Cadillacs so someone in your dealership should be aware of this problem.