Burning Smell in Cabin?

[tomg]

This could be oil blow but from lack of a catch can or Air Oil Separator. Under normal conditions, the crankcase gases exhaust into the airbox. These gases tend to have higher levels of oil mist under boost. This mist gets burned in the combustion chamber , possibly causing these smells. Just a theory..

going to check if that's where my smell is from next time I get it. thanks!!

Sponsored

 

[25_taco_stinks]

Has anyone succeeded in getting Toyota to acknowledge and repair this issue? My truck does it and Toyota is still not acknowledging the problem even after many dealer visits, inspection by a Toyota Field Technical Specialist, written request to Toyota corporate seeking repair, and lemon law arbitration.

 

[Groves8]

Has anyone succeeded in getting Toyota to acknowledge and repair this issue? My truck does it and Toyota is still not acknowledging the problem even after many dealer visits, inspection by a Toyota Field Technical Specialist, written request to Toyota corporate seeking repair, and lemon law arbitration.

I have never got them to find it, as I assumed would happen. I still have it happen after a long drive, hopefully someone eventually finds it.

 

[25_taco_stinks]

I finally got Toyota to acknowledge and repair this issue in May 2026. The first time I brought my truck in for this was in July 2025.

The problem with my truck was an exhaust leak from a weld joint on the upstream side of the catalytic converter, less than 18 inches from the cabin vent intake. To diagnose the leak I removed the upstream oxygen sensor and injected smoke with an automotive smoke tester through the upstream oxygen sensor bung. The leak was immediately obvious. See attached video.

My local dealership and the Toyota FTS rep characterized the exhaust smell I was getting in the cabin as normal and acceptable. It was only after I smoke tested the exhaust myself and presented the video to a different dealership that I was able to get this repaired.

 

[Rocko]

I finally got Toyota to acknowledge and repair this issue in May 2026. The first time I brought my truck in for this was in July 2025.

The problem with my truck was an exhaust leak from a weld joint on the upstream side of the catalytic converter, less than 18 inches from the cabin vent intake. To diagnose the leak I removed the upstream oxygen sensor and injected smoke with an automotive smoke tester through the upstream oxygen sensor bung. The leak was immediately obvious. See attached video.

My local dealership and the Toyota FTS rep characterized the exhaust smell I was getting in the cabin as normal and acceptable. It was only after I smoke tested the exhaust myself and presented the video to a different dealership that I was able to get this repaired.

Oh wow, that is it. Nice find. I wonder if leaking exhaust into the cabin would concern Toyota. Probably not.

 

[Kjc]

I finally got Toyota to acknowledge and repair this issue in May 2026. The first time I brought my truck in for this was in July 2025.

The problem with my truck was an exhaust leak from a weld joint on the upstream side of the catalytic converter, less than 18 inches from the cabin vent intake. To diagnose the leak I removed the upstream oxygen sensor and injected smoke with an automotive smoke tester through the upstream oxygen sensor bung. The leak was immediately obvious. See attached video.

My local dealership and the Toyota FTS rep characterized the exhaust smell I was getting in the cabin as normal and acceptable. It was only after I smoke tested the exhaust myself and presented the video to a different dealership that I was able to get this repaired.

Thank you for this video... Im thinking have have the same issue... It's not all the time but if I'm going up a large hill fast or it's a really cold morning I will get this exhaust smell... Mines a 2024 so I'm trying to get everything taken care of before I'm out of warranty

 

[25_taco_stinks]

Thank you for this video... Im thinking have have the same issue... It's not all the time but if I'm going up a large hill fast or it's a really cold morning I will get this exhaust smell... Mines a 2024 so I'm trying to get everything taken care of before I'm out of warranty

Sounds like the conditions when I noticed it most: cold start, climbing a hill, coming to a stop on a freeway offramp. Always with HVAC on fresh air, no heat or AC.

 

[Kjc]

Sounds like the conditions when I noticed it most: cold start, climbing a hill, coming to a stop on a freeway offramp. Always with HVAC on fresh air, no heat or AC.

I'm taking mine in soon but if I run into the same issue how much did you pay for the exhaust smoke machine? Or maybe take it to a muffler shop and have them test for leaks would be easier/cheaper... Only at 13k miles but have noticed since about 5k

Outside air only no A/C on.... Just hvac... I've changed my cabin filter already a few months back

 

[25_taco_stinks]

I'm taking mine in soon but if I run into the same issue how much did you pay for the exhaust smoke machine? Or maybe take it to a muffler shop and have them test for leaks would be easier/cheaper... Only at 13k miles but have noticed since about 5k

Outside air only no A/C on.... Just hvac... I've changed my cabin filter already a few months back

I paid about 50 bucks for the smoke tester on Amazon. Any auto shop should be able to do this test for you in an hour or less.

 

[BLtheP]

Been fighting this issue as well since I bought the truck new. I'm around 11,500 miles now. Definitely the most irritating thing about my truck.

I don't really use recirculate at all, I pretty much always switch it to fresh air mode when I start the truck because I like fresh air much better and as far as cooling load goes, even in 100 degree temps the AC cools very well. As such, I get whiffs of whatever this smell is occasionally. Haven't figured out why.

I notice this smell sometimes when I'm on the highway at higher speeds (like 80 mph this morning in 4th gear, 3800 rpm or so) and then almost always without fail, I roll up to my parking spot at work and back in. It's like as soon as I start to back up, something about reversing pulls in whatever that burning smell is. It is quite unpleasant.

I'd like to do the smoke test shown earlier in the thread, but what is the fix if that is the issue? Another cat, turbo, or gasket between them? With this seemingly happening to a lot of trucks, will this issue persist? Maybe it's just a small vocal minority, but most trucks aren't going to smell this on recirculate, which is the default. I'm curious what the root cause is.

 

[25_taco_stinks]

Been fighting this issue as well since I bought the truck new. I'm around 11,500 miles now. Definitely the most irritating thing about my truck.

I don't really use recirculate at all, I pretty much always switch it to fresh air mode when I start the truck because I like fresh air much better and as far as cooling load goes, even in 100 degree temps the AC cools very well. As such, I get whiffs of whatever this smell is occasionally. Haven't figured out why.

I notice this smell sometimes when I'm on the highway at higher speeds (like 80 mph this morning in 4th gear, 3800 rpm or so) and then almost always without fail, I roll up to my parking spot at work and back in. It's like as soon as I start to back up, something about reversing pulls in whatever that burning smell is. It is quite unpleasant.

I'd like to do the smoke test shown earlier in the thread, but what is the fix if that is the issue? Another cat, turbo, or gasket between them? With this seemingly happening to a lot of trucks, will this issue persist? Maybe it's just a small vocal minority, but most trucks aren't going to smell this on recirculate, which is the default. I'm curious what the root cause is.

The root cause is a bad weld on the upstream side of the catalyst causing an exhaust leak. The fix is to replace the catalytic converter, which is what Toyota eventually did for my truck.

 

[Tacohunter2024]

For what it's worth, I had a burning/oil burning smell for about 20k and the dealer couldn't figure it out. Eventually got the right technician, it was the gasket for the oil cooler. Apparently when that leaks, it collects on the skid plate and blows on the exhaust when you're on the highway...but doesn't really leave spots on the driveway. No issues since it was replaced at 57k.

 

[BLtheP]

The root cause is a bad weld on the upstream side of the catalyst causing an exhaust leak. The fix is to replace the catalytic converter, which is what Toyota eventually did for my truck.

Good to know, thanks. Guess I will be inspecting mine soon.

 

[GSPHerder]

Yesterday in the trucks small one car garage the smell was burning my eyes and nose. That was after a 1 hour run pulling a trailer.

Sponsored