Overheated?

I went out to vegas from LA this weekend to watch some desert racing and I had some problems with my car over heating. Once on the way out and once on the way back, I had smoke rolling out from under the car, typically right after a long climb.

The first time I pulled over, we traced the fluid up to right around the oil filter. It even looked like there was oil (it was dark) pooled in the lip on the front of the oil filter. The temp guage never got over about 225-230 (like the first line past 210), but I thought that maybe some engine oil got out there somehow. The fluid looked darker, not like AT fluid.

The second time, I noticed there was AT fluid up on the intake manifold by the TB were the trans cable connects and the other fluid looked more like AT fluid, though still darker and not really red anymore.

So at this point I'm thinking it was just the Tranny overheating (I don't have the factory cooler that comes with the tow/upcountry package.

What do you guys think?

99 4.0 AT 4x4 55K miles

The trip to vegas is through the mountains and it was about 120* the whole way this weekend... so I wouldn't be surprised if the tranny got hot, thinking about adding a cooler now.

Marcus

wouldn't be a bad idea and it sounds like you are on the right track

I will assume the atf up on the engine was from the trans dipstick tube?? How else could it get there.... If it was atf and from the tube then it was trans overheating. Usually when that happens the trans will push atf out of somewhere. Sometimes it will push the front seal out of the trans. Sounds like that was not the case this time. First of all, if it did get that hot then it definitely burned the fluid. Time to do two or three changes in a row (driving it some in between) to try to get out as much of the burned stuff possible, replacing the filter once...or take it to a trusted shop that has the machine to replace the fluid in it's entirety. Secondly, install a medium sized cooler taking sufficient time to totally properly attach and route the cooler rubber hoses to and from the line to the cooler in the radiator. Is not usually advised to eliminate the oem in-rad cooler because it really helps to keep trans temps good when cold ambient. Good Luck.

Tranny Fluid

My '90 did this on a trip up to Lake Isabella and after talking to my tranny guy I was informed there is an overflow hole in the front of the tranny, fluid leaks out, hits the exhaust crossover and walla SMOKE CITY!!

I guess it is failry normal and it went away after I installed a tranny cooler.

There is a cable that goes from my tranny to the throttle body. The fuid was directly underneath where the housing for this cable ends and so I can't imagine it came from anywhere but this cable.

I'll pick up a cooler and a temp guage and make sure that I leave the OEM radiator in the loop... thanks for the tip.

Marcus

What size coolers are recommended? How thick of a cooler can you fit in front of the radiator?

Marcus

I installed the Mopar Aux trans cooler on my 88 XJ. It has a surface area of 48 sq in. I found the aux cooler from the dealer costs more but it make up by the fact it a simple install. No lines to cut just disconnect and reconnect lines.

I think they changed the design but the factory aux cooler should have bracket for attachement to the chassis. Most aftermarket uses wire ties to attach the cooler to your AC condensor. I like the factory cooler, no rubbing problem and 5 years from now any mechanic working on the XJ will know what it is vs trying to figure out what the hodge podge of hoses goes to.

If your 99 like my 88 you will have to remove the front bumper. This will be the perfect time to install front tow hooks if you want them. The only additional work you will have to do is attach the tow hook brackets.

Don't get too large-

Have seen guys use coolers that cover the whole radiator practically!! That is such major overkill for this application is stupid. The thickness of the cooler is not what changes, but the width/height. Go to a good auto parts store and dig around in their assortment and see the range of sizes. Get something two steps from their largest or so. Have seen those through-the-radiator attachment mounts do just fine for many miles so don't necessarily run from that method. However, other mounting arrangements such as OEM designs are always the best, but way complicated and time consuming most times to construct.

If using the through-the-rad mounting connectors and your Jeep has A/C i do not like running those mounts through more than one rad. This would necessitate removal of the engine radiator so as to only route them though the A/C condensor. I also like to put a slight flair on the end of the cut trans line so as to help make sure the rubber hose (double clamped) to it stays there. When they blow off is a real mess.