95 Cherokee... overheats on highway

[RC51Ric]

95 Cherokee Sport 2 door 4.0 HO 2wd auto 100% stock 130k mi. Runs fine in all aspects, new coolent, oil is fine, no leaks, new thermostats.... but ever since i bought the thing a year ago, when on the highway in anything over 80 degree weather going over 70mph with the AC on, it will overheat... Or when towing a trailer on the highway if its anything warm outside it will light up that overheat light real quick, and the only way to keep it cool is to turn the heater on high. In a few weeks here i have to haul a 5x8 enclosed trailer from florida to maine with it, and this problem has to be solved by then. Ive been browsing thru the forum and i read something about the factory in rad tranny cooler causing the problem? At low speeds and at idle it never has any overheating issues no matter what you are doing. Contact me @ [email protected]

[Po Pilot]

Waterpump.

[RC51Ric]

the water still circulates... i thought water pumps worked or didnt...

[flurpo]

Originally Posted by RC51Ric

95 Cherokee Sport 2 door 4.0 HO 2wd auto 100% stock 130k mi. Runs fine in all aspects, new coolent, oil is fine, no leaks, new thermostats.... but ever since i bought the thing a year ago, when on the highway in anything over 80 degree weather going over 70mph with the AC on, it will overheat... Or when towing a trailer on the highway if its anything warm outside it will light up that overheat light real quick, and the only way to keep it cool is to turn the heater on high. In a few weeks here i have to haul a 5x8 enclosed trailer from florida to maine with it, and this problem has to be solved by then. Ive been browsing thru the forum and i read something about the factory in rad tranny cooler causing the problem? At low speeds and at idle it never has any overheating issues no matter what you are doing. Contact me @ [email protected]

RC,
Amen Bro,,,I have a 90 Laredo with the same issue. I put a new engine in and a new set of radiators. I had the problem before and I've still got it...I stopped even trying to use AC a year ago-now I have to keep the heater on to keep the engine from overheating on the highway. If anyone has a fix please let us know. Best,

[email protected]

[RC51Ric]

Im going to try the aux tranny cooler first, and if that helps alot ill also get a 3row rad and that should fix it

[MagicRat]

The radiator has insufficient capacity, likely due to age and rust/dirt blockage. My Cherokee used to do the same thing. A new 2 core radi fixed it right up.

[Po Pilot]

Originally Posted by MagicRat

The radiator has insufficient capacity, likely due to age and rust/dirt blockage. My Cherokee used to do the same thing. A new 2 core radi fixed it right up.

Forgot to think of that! I also changed out my radiator. I recommend a 3-core CSF from http://www.dpgoffroad.com/ $150!!! Great quality and cools better then anything on the market!

[xjtom]

Try Flushing out the cooling system, and a trans cooler should help

[b1gfella]

I agree about the radiator...they seem to be way undersized for what Jeeps are expected to do. Remember to change the radiator cap too...often overlooked but they wear out and cause issues like every other cooling system part.

[spooleffect]

Make sure you have a proper 50/50 mix. The largest radiator in the world won't do anything if you have too much anti-freeze/coolant because it doesn't transfer any heat, the water does that. New parts can't fix everything.

I have stock everything on my cooling system and have absolutly no overheating problems what so ever. 170,000 miles and counting on radiator as well.

Also about the towing, make sure its not more than the GVTW that your cherokee is rated for. Jeeps were not meant to tow very much, especially with the stock cooling system.

[RC51Ric]

Cooling is new, and correct mixture. It never overheats unless its on the highway over 70mph with AC or towing in hot weather. Probably the 1 core rad, ill get a 3row and tranny cooler and give that a shot... Why would they put 1 core rad with a 200hp 4.0L inline six? I thought dodge knew better then that...

[spooleffect]

Dodge had nothing to do with it. Jeep is barely linked to Chrysler at all.

Jeep just made a bad engineering decision with the radiator. It did the job but barely.

[bikechuck]

same problem w/my 94 stumped me for a yead. Radiator clean and flush cured it for less than $100. Take it to a radiator shop.

[twll]

Your overflow valve is probably clogged up.I went over everthing else before I discovered it when it broke off.There was still enough left on to refit the hose to it.Most of it is plastic.If it breaks off at the neck you can put a small steel fitting in it & use J B WELD to glue it back.That saved me from a new radiator $$$ .

[Js808]

If you haven't flushed the cooling system, do so. The transmission cooler is run through the radiator, so if your engine is running hot...your transmission is also running hot causing damage to both. If you are going to haul anything consistantly (once a week or more) you need to install an auxillary tranny cooler for sure. This will cool your tranny and engine because the heat the transmission introduced to the radiator is gone...thus cooling them both. Check to see what temp. thermostat you're running also. Don't remove it completely, but try running a 165 degree thermostat. That will help you on the highway. After you have exhausted all known rememdies, have the radiator boiled (it may be clogged at the bottom and not flowing efficiently) or replace it. You can buy a standard radiator for $130 all day long.