djlarroc

Not sure how to search this, so I'll just ask. When I'm on the freeway, and under acceleration, there is a burning smell. I know it's not my engine. I can only think it's something w/my transmission. Also, yst going to and from the trail we noticed smoke inside the cab around the back seat. Any ideas? I'm thinking of doing a tranny flush and filter but don't know what else.

nasonguy

Burning smell?

Like what's burning, burning oil? Burning Paper?

Check your exhaust systems, my bros car has a leaky muffler and when he gets on it it starts smelling like burnt *butt* hair in his car...

mud-dog27

ive cooked my AW4 3 times and never smelt any burning(you will see the smoke once you slow down as its burning off the exhaust) but you will feel it start slipping if its getting above 235*F which is getting up there.....if your cats clogged it can get real hot and start burning and stinking

djlarroc

I don't know how to describe it. Don't think I've smelled burnt butt hair haha.

But it only happens when I'm under semi hard acceleration, like going up a hill or passing a car. When I'm coasting on the freeway, the smell goes away. I just got a new cat and muffler and the smell was before that. I could literally see a little smoke in the cab. Maybe it's burning tranny oil somehow. I don't know. And don't know how to check it.

Long Island XJ

Do you have any oil leaks? might be dripping on x pipe and burning off.

Did you weld up new x system or use clamps? might have small leak.

Also what is the condition of the floors in your Jeep? sounds like you might have some holes causing smoke to travel in your cabin.

Have you recently added Tranny fluid? might have added to much causing fluid to leak out over flow vent.

check your floors and x pipe for any stains, also pull your tranny dip stick, whats the color? red good, brownish bad.

mud-dog27

if your transmission is spitting out fluid an easy way to check is to look at your hatch.....does it have oil on it? if so you have a decent leak....again speaking from experience

how old are the O2 sensors cause if they are hooped even with a new cat they could be telling the system to pour in too much fuel which gets to the cat and again can causes it to get real hot and long island asked is the exhaust system welded or clamped and have you checked for leaks

if your not seeing any ATF or loosing any i dont think its transmission

Abovetimberline

have you checked your rear main seal?I had this happen to me and it would leak on to the exhaust and look like it was about to blow-up,when I would go uphill the oil would collect in the bellhousing and when I would stop or go down hill it was bad,it would also smoke at other times,I found out it would not smoke if I let the oil level drop and leave it there,seeings I was deer hunting in wyoming at the time,i just watched the oil pressure.
If your trany got so hot it smoked,I think you would have other signs.

djlarroc

I just did my rear main a few weeks ago. I have no oil leaks. When I did the rear main, while moving the pan around, we knocked a tranny line loose. It was put back in pretty good, so it could be that, but I'm pretty sure it was smoking like that before I did the rear main. I have no carpet. I bedlined my floors, but they all looked solid when I sprayed them.

I do seem to remember my oil brownish. Reason I think a tranny service is in order regardless and hoping that solves the problem. But otherwise, I don't know what to look for.

djlarroc

Still tryin to fix this. Thinking of going to a shop and having a drain and fill and filter change. Anyone know how much that should cost? Or a link to where I can learn how to do solo?

Thanks

Turbo X_J

If the trans fluid is brown/black, it means simply that the trans is toast. Does the transmission slip? Try accelerating hard up an incline does it feel like you pushed on a clutch pedal & the engine just revs or does it pull hard?
BTW a trans flush is the quickest way to finish off a marginal transmission. After any number of miles the clutches will wear and the friction material will build up inside the trans. The power (pulsing) flushing style machines will loosen this material up and jam up everything from the valve body to the trans cooler.

ETA: Reread your post and saw this: "I have no carpet. I bedlined my floors, but they all looked solid when I sprayed them." Are the heat shields in place on the exhaust? Is the floor over the exhaust hot?

djlarroc

The floor over the exhaust is super hot. I have some rubber mats but it's still pretty hot back there. I can only smell the burning when I'm accelerating on the hwy. Driving through town is none to minimal. The tranny shifts fine. No slipping. I was not going to do a power flush, just drain and refill and replace the filter. Although now I'm thinking of just draining and refilling to get clean fluid in there and maybe do the filter next year.

iateeple

check your fluid, dark/brownish fluid does NOT neccessarily imply bad tranny IF the fluid has not been changed for an extended period of time AND it does not smell strongly of a burned oder AND it does not have metal flakes in it. If it looks decent and the level is correct(checked in neutral at idle after driving at least 20 miles) i would start looking elsewhere, what is the possibility that it is an electrical something buring INSIDE and not something getting in from outside? Just a thought for ya :-)

mike albo

Did check around your valve cover,what about oil filter adapter did you change the o-rings?

chereveco

I just changed my AW4, for a used imported from US down to Costa Rica, just finished installation a week ago, used mopar ATF Dexron IV, ( + 4 ), direct from the dealer, also installed a new filter. Before my original trans got burned the heat coming from underneath the jeep was like from hell, if i just stoped at a traffic light you can feel the hot air coming from under the car.

With the "new" trans. Once again the floor under the front seats gets real hot, I have instaled some heat difusors ( the one that is used under roofs to prevent building up inside some kind of foam with aluminum on one side ), plus i installed an aluminum heat deflector over the catalytic, and finally got some special racing heat insulator wrapped on the curved pipe in front of the passenger seat. Today drove de car after all of that for an hour and a half climbing a very light hill and the car started to build heat again until I had to turn the A/C on, crazy on the cold air of december.

I need a really good advice on how to cool down everything from the floor to the trans.

Mine is a 102.000 mile 4.0 2001 cherokee sport

Thanks on any advice

Regards,

chereveco
From Costa Rica,
ndejongh@hotmail.com

Nehlstay

Does it smell sweet? If so, it probably is your tranny.

However, I had the same burning smell after moderate acceleration or while/after accending a hill. It turned out to be my oil filter adapter leaking. The position of the oil filter allows for the oil to drip on one of the hottest parts of the exhuast (right before the cat) during acceleration or when going up hill.

hope this helps.