Burning Smell after long uphill hiway grade.

I have a 5th gen TRD-offroad with 23K miles and on a recent trip (I did 7hrs that day) driving back from Colorado going West on I-70, I smelled a bad burning small (burnt rubber/oil smell) coming from the car when I stopped at a rest stop. Not sure where it was coming from....

I was trying to maintain 80MPH (the posted speed limit) and was averaging 3-4.5 RPMs. I hit 4500 a few times before backing off the throttle because it sounds like the engine is going to explode at that RPM.... I would say at least 3K RPM for the 4runner to maintain speed up this steep grade.

The elevation was around 5K-7500 ft ASL. Very steep grades and high elevation.

Anyways, what would cause this smell and is it someone I should be worried about. I've done regular maintenance and changed oil/filter every 5K miles.

*I have not smelled this again and it was a one-time deal so far. I never really every get above 3K let alone 4K RPMs during my regular driving as the roads are pretty flat around home.

 

Was your transmission shifting up and down a lot? It could be transmission fluid that is the odor.

Another reason could be your brakes. Were you riding the brakes or using them frequently on this drive?

 

This stretch was mostly all uphill for a LOOONG way and I stopped at the rest stop going uphill... so I don't think it would have been my brakes. I think I had cruise control on and yes, it was prob. shifting more than I liked to maintain speed. This hill really shows the sluggishness of the 4runner, it's a beast of a uphill drive.

 

Probably would be worth investing in a tool to monitor your trans temp if you're going to drive that stretch of I-70 regularly.

 

Yeah I think I will. I only make that drive about once a year but would be nice to see what my temps are.

 

You want to try and hold a gear instead of having the transmission shifting up and down frequently. THat can cause damage. Keep it out of overdrive.

 

I had the same thing occur once on a trip through Arizona high country in June. Cruising at 65-70 up grades, AC blasting, 100+ degree temps etc.

After that unusual smell went away (similar to burning clutch) I was never able to replicate it again.

 

There really is no reason to beat on your vehicle just to maintain the posted speed limit. You don't have to go 80 just because that is the speed limit. But it sounds like your break in is now complete. On long, steep up hills I usually throw the trans into 4S mode and just maintain an rpm I am comfortable with, but that is no where near 80mph.

 

I noticed on my 5th gen that I got at least 1 MPG better if I did 75 instead of the posted 80 and it seemed like the car wasn't working nearly as hard to maintain the speed, so I usually chose to do 75 even though 80 is more fun.

My current 4th gen V8 does 80 no problem.

 

I have the same smell only on my way home. Which just so happens to be up hill also. Residential so I'm only going 25 - 30 but I notice the smell when I park also.

It goes away quickly just never bothered to dig too much into it.