btowhey

Something odd is happening with my '99 Cherokee Sport. It runs perfect, and has plenty of power and the temp seems okay and everything, but when I get up to 65-70 mph, a pretty heavy smoke starts to come out the back.It is mostly a white smoke and as soon as i drop down to 55-60 mph it stops again. All oil pressure and levels seem fine, so all i can figure is a possible EXTREMELY small leak in the head gasket, any suggestions on what could cause it?

Turbo X_J

Compression test?

Lowrange2

I bet 2 bucks your transmission is getting hot and puking fluid out on the exhaust.

What size tires are you running? What gears?

I'd imagine that it doesn't do it until you've been driving for a while. Am I wrong?

btowhey

thanks for the input guys! they are Hankook Dynapro Mt tires and its an auto tranny with just stock gears. The entire jeep is stock except for the tires, could this cause the transmission to overheat? and if so is there a way to cool it down?

Lowrange2

The size of tire is what's important. If the Jeep is stock I'd assume they're 235/75R15s at most.

Perhaps that's not the issue but I suppose that it still could be.

Check the fluid level for starters and climb under the Jeep. I'd imagine there's going to be fluid splattered all over the under side. See if the fluid seems more like transmission fluid or engine oil.

Does it seem like it's smoking out of the tailpipe or from under the Jeep?

btowhey

man you are good! they are Lt215/75r15's and yes there is some splatter under the jeep and it SEEMS like oil, but im no expert. as for wether or not its the tail pipe or just out of the back i dont know since im the one driving, but it does seem to be across the entire width of the jeep when it smokes, so maybe it is coming out from under. be straight with me, is this a big problem? or a smaller fix if it is the tranny,

Lowrange2

Get a white paper towel and wipe some of the fluid off with it. Transmission fluid should be red and thinner than oil. It smells different too. (Tastes a little different as well.)

If it's the transmission puking fluid it most likely just needs a new front seal and figure out why it's getting hot. Maybe add an aux transmission cooler? Either way, it needs to be addressed or you'll be replacing the entire transmission.

I see no reason why a stock Jeep would run the transmission hot though. I assume the OEM cooler is still in place?

Where do you live? How many miles are on the Jeep?

Try driving the Jeep in 3rd instead of "D" and see if it still does it.

btowhey

well with that info, it is definitely oil, there are about 198,xxx miles on the jeep, i live near atlanta Ga.and i will run the can in 3rd as soon as i get a chance.

Lowrange2

Well, burnt transmission fluid can be brown or black like oil... Either way, there's quite a few friendly Jeepers that I'm aware of in your area. Start a thread in the NAXJA SEC forum or here in the South East Forum and I'm sure someone closer may be willing to help.

If all else fails I'll buy it from you.

Got a picture of it?

btowhey

hey man, thanks a lot! you've been a great help. I was actually thinking of selling it soon! I just miss a small quick car (used to have a 92 nissan 300zx). and yeah! its in great condition cosmetically except a small dent on the back hatch.
http://i1076.photobucket.com/albums/...whey/jeep.jpeg