Smell of something burning at 90+

[Sirtimothy92]

In my 92 MTX everytime i go over 90 or 80 under hard acceleration I start to get a strong smell of something burning almost right away any ideas guys? I was gonna get one of those laser thermometers and hit every hub or Axel and see if anything is hot hot. I hop out to try to sniff it out when this happens but the smell is gone by the time im off the freeway and pullled over. Also what do you guys torque your lugs at ive always done 100 lbs with all my vehicles.

 

[zoomlater]

is it coming through your vents or from outside the car
you can touch your wheels to see if they are hot, dragging brakes

 

[Sirtimothy92]

Id say its coming through my vents. Ya I touched wheels and they felt normal. Here's the thing though the car coasts fine in neutral but it does seem like it slows down while in gear faster than it should. I might be trippin though. Like I swear I smell it more when im on the throttle. Can axles lose their grease causing them to get hot and smell?

 

[yaycandy]

Wheel bearings heating up maybe but doubtful after a minute of thought.
In my short life so far ive learned not to overlook anything. So its possible.

Tires at max speed ratings heat up but probably not enough to smell burning instantly.
Increased air flow through car at those speeds also.
Got me stumped.

Edit: I actually had this happen on my 15 sho from rear wheel being over tightened. I guess rotor rubbing on back pad. So another possibility.

 

[RonPorter]

If it's coming through the vents, it's most likely not from the rear wheels. Something out of the engine compartment could find its way to the cowl air intake.

100 on the lugs is good.

 

[Sirtimothy92]

Its just strange that its not necessarily the speed but the speed while in gear. Because right when I put it in neutral the smell goes away. Im gonna check my trans fluid and make sure im good on that just in case. Once i get that thermometer I can start looking at temps. Would you guys advise putting the car on stands and getting up to speed to see if anything happens? Good idea or no?

 

[SHOrod]

IWould you guys advise putting the car on stands and getting up to speed to see if anything happens? Good idea or no?

If this only happens with speeds above 80 mph, this is most definitely NOT a good idea. You'll damage more than what you're trying to fix for sure. However, if you have access to a front wheel drive chassis dynamometer that might help find the source in a relatively safe and convenient manner.

-Rod

 

[Jbeck]

what kind of smell is it? Is it an electrical burning smell, rubber burning smell, paper burning smell, ect ect....that could help track down the source. See if you can describe what kind of material it smells like burning. I would say right off hand to check the rear bank exhaust mainfold for anything resting on it or something like that because its close to the cowl vent to pick up vapors and under acceleration it might not be touching or close to manifold....maybe something is shifting under acceleration....I knew a guy that burned through his main harness because under hard acceleration it would shift and rest on the rear bank manifold....burned all the way through it and the car was never that same after it was repaired.....just another perspective.

 

[BaySHO Performance]

Brakes dragging? Unlikely. Engage first at a stop, get the car moving slowly, then put it in neutral and let it coast to a stop again. It shouldn't come to a stop with a ****.

I just had this problem on a client car. Burnt oil smell in cabin, but only going uphill. Run your finger along the bottom of the camshaft sensor to see if it's wet with oil. If so, replace the seal. You might also consider replacing the camshaft sensor: they don't like getting oily.The reason you only smell it at speed is the airflow redirects the oil onto the cat, where it burns.

Another possibility is a power steering leak, either from the pressure hose or the rack itself if the end seal has failed.

 

[RonPorter]

As the above comments mentioned, I'm suspecting an oil drip on the exhaust, and the increased airflow at speed brings it up to the intake vents.

 

[NoSlo]

As the above comments mentioned, I'm suspecting an oil drip on the exhaust, and the increased airflow at speed brings it up to the intake vents.

Yup, stupid car - valve cover, oil sensor, pan, cam or crank seal leak? It all ends up burning on the cats.

Probable cause is excessive blow-by, more than the EGR/vacuum can scavenge, causing leaks around the front seals.

 

[PaulTAutoX]

IIRC the lug nut spec is 94 ft lbs. While being a little high is better than too low, and torque wrenches may not be accurate, I wouldn't go over 100.

the other suggestions are good. One idea is to look at the under-hood pad for being indented. A broken motor mount will allow the engine to rise up under heavy loads and press there, and the torque being applied to drive to a constant high speed might be lifting the engine. That movement might be allowing something else to move and lean against something hot as suggested above.

 

[BaySHO Performance]

Spec is 80-110 ft. lb. for the lug nuts. I set them bang in the middle at 95.

 

[RonPorter]

We've always done 100, and that's usually the standard for tech at a track event.

 

[Sirtimothy92]

Sorry its been awhile since i replied but who wants to know the cause of the burning smell???

 

[Toolman]

Sorry its been awhile since i replied but who wants to know the cause of the burning smell???

Inquiring minds want to know.

 

[SHOMON]

Sorry its been awhile since i replied but who wants to know the cause of the burning smell???

Well Sir..?????

 

[RonPorter]

Sorry its been awhile since i replied but who wants to know the cause of the burning smell???

You stopped eating beans?

 

[Sirtimothy92]

So it happened to be my rear passenger strut rubbing on the tire. The very bottom of the strut "seat" has been slightly rubbing on the inside edge of my tire. I scooped off a handful of my new Pirellis all ground up from the inside of the wheel well. It rubbed a nice groove on the inside edge right where the tread starts. I believe this was caused by a loose/ stripped pinch bolt.

 

[zoomlater]

So it happened to be my rear passenger strut rubbing on the tire. The very bottom of the strut "seat" has been slightly rubbing on the inside edge of my tire. I scooped off a handful of my new Pirellis all ground up from the inside of the wheel well. It rubbed a nice groove on the inside edge right where the tread starts. I believe this was caused by a loose/ stripped pinch bolt.

What size of tire are you using?