Burning clutch/brake smell

[a t l a s]

Took my new (2k miles) 4Runner into the mountains this past weekend and was trying to take it relatively easy since the motor is still in the break-in period, but there were times where I had to apply a bit more skinny pedal.

I stopped for gas after some amount of winding highway, and walked past the front of the truck noticing a burnt clutch (I know we don't have a clutch but that's what it smelled like) or a burnt brake smell coming from the engine bay. It was especially strong when I popped the hood.

I searched here on the forum and all I could find are reports of a burning brake/rubber smell coming from the rear which is speculated to be the exhaust hangars. However I am certain that this smell was coming from the engine bay, or at the very least somewhere on the front of the truck. I did not notice the smell again for the rest of the trip up or back home, but I wasn't actively checking either.

Any ideas as to what this could have been?

 

[LandCruiser]

Did you engine brake or ride your brakes going downhill?

Sounds like you overheated the brakes.

 

[a t l a s]

Did you engine brake or ride your brakes going downhill?

Sounds like you overheated the brakes.

I suppose overheating brakes was a possibility, but I just looked at a map and realized that I hadn't even hit the mountains and winding roads yet when I noticed the smell. I stopped for gas in Placerville going east on I50, which up to that point is a relatively tame/mundane stretch of highway.

If it is indeed overheating brakes, that is somewhat concerning.

 

[Big_Cuss]

The brakes actually take awhile to bed in, too. You'll notice when brand new the discs have a machined surface to them, and it takes awhile for the pads to polish them, and for the pads to perfectly wear to fit all the surface irregularities, too.

You probably just smelled the brakes getting a tad overheated on the surface from bedding in.

 

[LandCruiser]

I suppose overheating brakes was a possibility, but I just looked at a map and realized that I hadn't even hit the mountains and winding roads yet when I noticed the smell. I stopped for gas in Placerville going east on I50, which up to that point is a relatively tame/mundane stretch of highway.

If it is indeed overheating brakes, that is somewhat concerning.

Winding mountain roads are enough to cook the brakes on a 4500 pound off road vehicle.

 

[Teamoatmealpie]

http://www.toyota-4runner.org/5th-gen-t4rs/151090-burning-rubber-smell.html

http://www.toyota-4runner.org/5th-gen-t4rs/232801-rear-has-burning-smell.html

That mystery has been around for awhile as you saw on the previous threads. I'd guess its the same thing. Mine stunk from the rear but I'd also at times thought it was from under the hood too.

 

[mynameistory]

I too have noticed this smell, exactly as you described. Mine wasn't on a new vehicle (bought used with 15K) and it wasn't the brakes. I was driving with family+dogs+ gear through Sonoma in June. It was about 105º outside, cruise control set to 65, air conditioning at full blast to keep the dogs in back cool.

We pulled over for a bathroom break and the engine smelled like it was cooking a clutch. It hasn't smelled that way again yet, but maybe I haven't worked it that hot/hard again since. Even on that trip, taking it up and over passes and through more hot desert weather, never smelled it again. Engine temp never went over 3/8 on the hot/cool scale.

 

[Tuc4R]

I've noticed mine will smell sometime also. It's in the rear though, but does smell like hot brakes. I looked this last weekend, and found nothing. :bash:

 

[MTN4RNR]

No smoke, no fire, no problems. Just consider it "breaking in smell". I wouldn't lose sleep over it. Took a little bit of time for mine to break in and lose that "hot" smell. Not a concerning hot, just a "well that smells hot"...hot...

 

[Brown2mu]

Had the same smell come from the front end. I had just got done doing some construction off roading trying out the 4 wheel features. I attributed it to mud being around the brakes and burning up 16 TEP 37k on clock


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[A10MileHusker]

I had the same exact smell in my 2017 when I first bought it. The first couple times of "heavy" use with winding and incline roads I would notice it more. I just attributed it to, as [MENTION=129593]MTN4RNR[/MENTION] said, its just a breaking in smell. It will go away. Nothing to worry about.

 

[a_double]

Thread revival.

I have a 2020 with <2k miles.

I get the burning smell on short uphills on surface street speeds. Maybe. 50-55 mph max.

 

[a_double]

I came across this:

Attention Required! | Cloudflare

what do you all think?

 

[Smitty19TRD]

Meh, I say don't worry about it. I and some smells for a bit. Also had them on my last two new vehicles.

 

[itr1275]

I have a 2020 with ~500 miles and it stinks occasionally too. It's normal for new cars to have some sort of coating bits here and there. It gets burned off eventually. Kinda smells like burnt plastic.

In your case you have 2K miles and I would expect it to be done burning off whatever it was. So it could have been the brakes, you where in the hills. Perhaps you were tossing into the turns a bit much and they got hot.

Brake material is similar to clutch material and has a sweet smell to it.

Rubber exhaust hangers shouldn't burn.

 

[rightyouareken]

I have a 2020 with ~500 miles and it stinks occasionally too. It's normal for new cars to have some sort of coating bits here and there. It gets burned off eventually. Kinda smells like burnt plastic.

In your case you have 2K miles and I would expect it to be done burning off whatever it was. So it could have been the brakes, you where in the hills. Perhaps you were tossing into the turns a bit much and they got hot.

Brake material is similar to clutch material and has a sweet smell to it.

Rubber exhaust hangers shouldn't burn.

I agree. I recently did a bit of steep uphill offroad wheeling with my new 2020 (~1600 miles) and noticed the same thing when I stopped to check my line on a few occasions. My theory at the time was the transmission fluid was probably getting pretty hot creeping along over the rocky climb even though I was in 4lo. Probably built up quite a bit of heat in the torque converter...probably hotter than it's been since new. My guess was that was just burning off some residual oil/coating from manufacturing. I wasn't and am not concerned. New cars do tend to smell when they get hot.

I also wonder if because 4Runners are built in Japan and have to sail across the Pacific (a trip that takes 3+ weeks in a salty/humid environment) Toyota might proactively spray the undersides with some type of light rust prevention coating that burns off in the first few hundred/thousand miles.

 

[themaestro]

My 2010 with 126k miles still gets that smell when I drive it hard. I always assumed it was the catalytic converter :noidea:

 

[Pirateghost]

I also wonder if because 4Runners are built in Japan and have to sail across the Pacific (a trip that takes 3+ weeks in a salty/humid environment) Toyota might proactively spray the undersides with some type of light rust prevention coating that burns off in the first few hundred/thousand miles.

They aren't lashed to the deck of some sailing ship. These are driven down into sealed holds of massive ships with probably zero ventilation to prevent the problem you are mentioning.

 

[itr1275]

My 2010 with 126k miles still gets that smell.

Yeah my 2011 did the same thing, usually after I had a fat burrito for lunch.