So that burnt rubber smell - solved (2013 BRZ)
 

Gentlemen:

So I bought a Certified Pre-Owned 2013 BRZ with 10k miles.
Because it's already broken in, I've driven it hard since day one. And in the two weeks I've owned it - I've noticed a burning rubber smell coming from the engine bay.

After reading a few threads online that were full of theories and guesses - from engine oil, engine treatments, break-in smells, etc. I decided it was time to look for myself. I tried checking the automatic cover for leaks, none.

The smell was especially strong around the serpentine belt and matched what I had been smelling. I ran my fingers along the belt covers on the alternator and AC unit. Black rubber dust coated the inside of the covers. Hmmm.

I pulled the covers off to confirm they weren't rubbing the belt, they weren't. I then ran a flashlight beam along the belt-way. Nothing touching or rubbing BUT... the catalytic convertor... pretty darn close to the belt... like a few inches.

Cats run pretty hot.

So my conclusion, when the cats are at their hottest, they cook the drive belt.
Also contributing to the burning rubber smell is the rubber dust off the belt.
(My old E36M3 used to cook the drivers rear tire as the muffler sat within an inch of the tire.)

Just letting you guys know and keep an eye on that drive belt.

Interesting, I am assuming you are talking about the cat on the oem header?

That is why there is that massive heat shield for the factory exhaust manifold.

Yep the cat on the OEM header.

On the passenger side, lift the hood up - orient yourself to the radiator, then look between the radiator and motor. You can see the O2 sensor wire going down to the cat... a few inches to the right, the main crank pulley... and the drive belt. (Also nearby are some wiring and the back of the radiator fan bracket.)

I'm going to keep an eye on the belt and cat. Figure every oil change is a good habit to inspect this area. For now, I think it's okay, but given a few years, that much heat is gonna break down the rubber and plastics.

But amazing the amount of rubber powder from the belts after 10k miles that I found under the belt cover. Run your fingers under it to confirm my findings.

If I theorize correctly, the powder falling on the cat get's vaporized pretty fast, which is what causes that burned rubber smell.

I know this thread is old, but looking forward to seeing if this is my issue too.. Just started smelling the rubber smell at around 4k miles on my '17 86. Too many miles to be cosmoline/coating burning off exhaust parts, and definitely rubber smell. Only happens when I've driven for a while, and is more present if I have been revving hard.

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Can you smell it while you are in the car when it's moving .. ??

Or, does it just smell when the car is stopped .. ??

Is the smell coming from under the hood ..??


humfrz

:burnrubber:??

Do you have an after market crank pulley or any other pulleys?

I remember seeing a thread about this burnt (rubber/plastic) smell a few years back. It seemed like a normal thing for most people on brand new 86s, mines included. Don't remember how long it lasted on my car, but I didn't bother with it.. it went away eventually.

Mines definitely didn't last 10K miles though, so yours might be a different issue. BTW, I've been running an aftermarket header with a CAT for a few years now, minus the heat shields.. no burning smell issues.

Maybe it's that green goo on engine, burning off? Or some exhaust sealant? Even more so that just 4K miles, so before that car probably was running very lightly during brake in period, so getting hot way less, thus that stuff may burn only now :)