Help!! Still trying to diagnose this burning smell!!

[fightman80]

As some of you might know... I've been trying to diagnose a burning smell that I'm getting while driving on the highway. I've checked my brakes, and fluids today... and can't find anything that would cause this smell.

The only thing I can see, is my rack is leaking fluid, is it possible that it's leaking on something and burning off???

Also, I want to check the front diff fluid.... can anyone direct me to a thread that shows you how to do it?? I've been searching Google and this site for over an hour...

 

[Devens]

I'm still very green on mechanical workings of my 4Runner(96 limited 4WD 3.4), but I have a similar issue and believe it to be related to loose bolts holding down the driver side valve cover. I noticed if I stay under 2k RPM I don't smell the burning nearly at all.

 

[jfeltT4R]

I know you said you've checked your brakes, but did you happen to check and make sure the e-brake isn't stuck. I had burning smell and it ended up being a stuck e-brake. I also had another burning smell that took me forever to figure out but it was a very small and slow head gasket leak. Hope this helps. You've got a super nice truck there.

 

[clemson4r]

Have you looked at leaking valve cover gaskets? Does it smell once you're stopped?

Max

 

[fightman80]

I can't see it being my valve covers... as I've had those leaking before... and it didn't smell like this. As for the e-brake... it's not engaged.

Any other suggestions? How about that how to on the front diff??

 

[jfeltT4R]

I can't see it being my valve covers... as I've had those leaking before... and it didn't smell like this. As for the e-brake... it's not engaged.

Any other suggestions? How about that how to on the front diff??

Not sure about the front diff, I've never had any issues on mine. When I took mine to the stealers to see what was up they told me it was a stuck e-brake. I called bs because I never use it. But the mechanic took me back and showed me. It was stuck right up, out of no where. After re-lubing I haven't had any problems since. I guess the trick is, if you don't use it, it may end up getting sticky. This may not be your problem at all but I suppose it's worth a try to engage and disengage the brake a few times and see what happens. Oh and the brake burning smell is the only burning smell I've ever experienced while actually driving.

 

[PNW yota]

I've had a burning smell that I eventually tracked down to my front diff on my solid axle jeep. Turned out water had gotten inside, it had the classic chocolate milk look. But I only smelled the burn when driving with 4wd engaged, which is was clued me in.

Just drop your skids if you have them, and look for the fill hole on the front it's pretty hard to miss. Can't recall the socket size but I have a very limited set and one of them fit. Fluid level should be just below the fill hole when cold and not chocolate milk colored

 

[LittleCaesar]

I've had a burning smell that I eventually tracked down to my front diff on my solid axle jeep. Turned out water had gotten inside, it had the classic chocolate milk look. But I only smelled the burn when driving with 4wd engaged, which is was clued me in.

Just drop your skids if you have them, and look for the fill hole on the front it's pretty hard to miss. Can't recall the socket size but I have a very limited set and one of them fit. Fluid level should be just below the fill hole when cold and not chocolate milk colored

I'd try this first, since your buried the front end into a big snow drift the other week. The fill hole is on the front, the drain hole is on the bottom right I believe if you are looking at the 4runner from the front.

When you changed the valve cover gaskets did you change the cam plugs and take the half moons out and reseal them?

You would have to be throwing around a large amount of atf fluid from the rack to have it burning on the exhaust.

 

[amalik]

As some of you might know... I've been trying to diagnose a burning smell that I'm getting while driving on the highway. I've checked my brakes, and fluids today... and can't find anything that would cause this smell.

The only thing I can see, is my rack is leaking fluid, is it possible that it's leaking on something and burning off???

Also, I want to check the front diff fluid.... can anyone direct me to a thread that shows you how to do it?? I've been searching Google and this site for over an hour...

You can find how to check your Front Differential fluid in this link:

Changing Your Front, Rear, Tranny & Transfer Case Fluids - ToyotaWiki

 

[fightman80]

Not sure about the front diff, I've never had any issues on mine. When I took mine to the stealers to see what was up they told me it was a stuck e-brake. I called bs because I never use it. But the mechanic took me back and showed me. It was stuck right up, out of no where. After re-lubing I haven't had any problems since. I guess the trick is, if you don't use it, it may end up getting sticky. This may not be your problem at all but I suppose it's worth a try to engage and disengage the brake a few times and see what happens. Oh and the brake burning smell is the only burning smell I've ever experienced while actually driving.

I looked at my e-brake before typing my last post... all was good! Thanks for the reply man!

I've had a burning smell that I eventually tracked down to my front diff on my solid axle jeep. Turned out water had gotten inside, it had the classic chocolate milk look. But I only smelled the burn when driving with 4wd engaged, which is was clued me in.

Just drop your skids if you have them, and look for the fill hole on the front it's pretty hard to miss. Can't recall the socket size but I have a very limited set and one of them fit. Fluid level should be just below the fill hole when cold and not chocolate milk colored

I'll take a gander at it... needs some preventative maintenance anyway!

I'd try this first, since your buried the front end into a big snow drift the other week. The fill hole is on the front, the drain hole is on the bottom right I believe if you are looking at the 4runner from the front.

When you changed the valve cover gaskets did you change the cam plugs and take the half moons out and reseal them?

You would have to be throwing around a large amount of atf fluid from the rack to have it burning on the exhaust.

I believe we did... but not quite sure... it's been 2 years now...

You can find how to check your Front Differential fluid in this link:

Changing Your Front, Rear, Tranny & Transfer Case Fluids - ToyotaWiki

Thanks for the link man! I'll check it out! That being said.... looks like we found the culprit! While unpacking my truck from our recent trip, my wife found some curtains that she bought at IKEA, while we were in Vaughan for my training course. They smelled the same as the burning smell, and were packed in the truck, just above where my exhaust is shooting up (broken exhaust :/ ) Turns out my exhaust was overheating the floor of my cargo area, and making the carpet heat up something fierce.....

IT took 2 months to get the exhaust parts shipped up here from Magnaflow.... but I finally got them! Install should be on Friday!



I'm making my own cat back system using parts from my stock setup and these.... when I'm done, I'll have a full stainless system, with a Magnaflow muffler!

I'll post pics in my build thread when it's done!

 

[MAD 69]

I have had the same burning smell as well, it smells like after you change your oil and some drips on the engine but this has been going on for 4 years! Have had a number of mechanics check it out and none could find anything wrong, my truck runs great but would like to find where it's coming from, I'm hesitant to Go long trips with it...

 

[fightman80]

This smell is not the same as the one you speak of.... I have had that smell as well. The smell I speak of, is much stronger than burning oil...

 

[blizz86]

Where is the smell coming from? After repairs on my inner axle seals (rear) i had a distinct gear oil burning from leftovers in the rear shoes.. obviously its gone now.