I have a 2000 3.4 SR5 4wd and I was heading out today and as I was merging onto the freeway I floored it and it smelled like something was burning in my engine. I've noticed this before but it seemed like the smell had gotten stronger. I had changed my oil 2,000 miles ago and it was Amsoil so I don't think its that. I checked all of my fluids and they seemed fine. If someone could give me an idea to what that smell is, I will appreciate it.
Oh by the way, I have 58,800 miles on the runner so maybe I am due for an ATF change?

 

What did it smell like? Paper, wood, plastic, rubber, oil, etc...?

Smells that I can think of are oil, ATF, antifreeze, brakes, and tires.

Steve

 

Any leaks?

Plastic bag on the exhaust?

 

I've gotten the same thing in my '91 4Runner when I floor it. I haven't been able to track down what it is, but I'm positive that it's because of being floored, because I only get the smell after I've floored it, or even after going up a steep hill/grade. Usually after running at higher RPMs for an extended period of time, and flooring it are the only times that I get the smell. So your guess is as good as mine, I changed my ATF about 3 months ago (1500 miles or so) and didn't change anything (except it shifts a lot nicer now )

-Braden

 

hmmm, is it possible that it is the Amsoil? , because like Patrick D, I just switched to Amsoil on my last oil change (which was 2 weeks ago) and I smell something burnt also when I floor it. I checked for leaksn and there were none. But here is the kicker, I just had a Transmission flush done 3 days ago and also converted to Amsoil Universal ATF, now the smell is no longer there when I floor it (or accelerating uphill)

 

There are no leaks on my runner and I can't quit place the source of the burning smell though I did recognize that it was a burning smell so maybe I just need to think on what it smelled like.
Also it is similiar to the problems that were discribed, it happens at high RPM's and when I am traveling up a hill. I will probably switch over to Amsoil ATF soon and hopefully that will fix it.
Any other opinions would be great.

 

Ok, it smells like burning electronics.

 

The smell you guys are smelling is the smell of hot metal, i have the same problem on my 93 4Runner, execpt mine is a little more often because i have 35 inch tires and 4.88 gearing. it smells like burning electronics, but it is just your engine, no harm is done i have checked it out a million times, and torn my engine apart to look for wareing but ther is none. almost all 4Runners that i have been it have that same smell when engine is running at high temps.