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Hello there, I have an 87’ mj 2.5L, having a serious problem with overheating. For the first two weeks i had it it was constantly overheating, then in one afternoon i put a new rad in, new thermostat, new filters, and an oil change. Immediately it solved the overheating issue. Been about a month now of smooth and perfect temp running, until it sat for a week then started overheating again. Before it was the radiator overheating, now it seems to be smoking out of the back of the engine block. I’m thinking it has something to do with the thermostat, if anyone has any ideas or solutions or want more information, please let me know!!! Thanks

I feel like my Jeep won't get up to temp. I posted elsewhere and was told it was nothing to be concerned about.. So per an IR thermometer at the t-stat housing, the coolant will get up to 170-175 degrees after 20-30 mins of mixed driving. -The heat works great and both heater hoses are hot. -The upper radiator hose gets warm-hot. -The radiator is reading 100-130 degrees via IR thermometer. The radiator cap does not get hot. It was 43 degrees out when I did this drive. 88 Comanche with open cooling system, 4.0l. Flushed the (already pretty clean and under 2yr old) cooling system 2 times, once with VC9 and the other dish detergent, with no heater core in the loop. Then replaced heater core, and put in a new 195 degree Stant thermostat. Coolant is roughly a 50-50 mix and all new. I did all this and now it won't get up to temp. Before this the Jeep always ran perfectly at 205/210 and never had an overheating issue. Any ideas?

Hello again, So I finally got around to changing my thermostat. Now I can not seem to get the housing sealed or when putting the housing on the thermostat is coming out of place. this was my second attempt, after my first attempt I bought a new housing thinking the old one may have been warped etc. However, after getting installed last night it is still leaking badly out the side. First time I only used a Gasket (felpro), second time I used the same gasket and Permatex #2. Any advice, tips or possible things I could be doing wrong? Thanks in Advance.

So my water pump bearings are going bad, so since I am changing that I was going to replace the thermostat. After reviewing threads I know to get a 195 thermostat, and as suggested in a Old thread looking for a OEM but I have not been able to fine one. The ones I have found at local parts store, none have the hole/needle. Can/should I drill a hole? Any suggestions on finding a OEM? Thanks, Whiz

I hate having to deal with crappy paper/cork gaskets, but I have yet to find a decent rubber replacement gasket for either the T-stat housing or the timing cover. I have a feeling that there might not be one for the t-stat, but i was hopeful for the timing cover. Anybody have a p# or link? EDIT: I remember a while back my brother had brought a roll of some kind of specialty gasket maker. It was some seriously bada** stuff. After some serious digging on google i determined this is what it was/is. PTFE FLANGE JOINT SEALANT http://www.gasket-tools.com/sealants-ptfe-joint-seal.asp Its cut-able, compressable, easily molded and shaped with your hands, resistant to both exteme ends of the temperature spectrum (-400 - 600 :eek: ), extreme liquid and gas pressures, its non toxic, and will not degrade.

Hi! Been a while since I've been on the forums. I've been busy putting my rebuilt motor back in the MJ and putting some break-in miles on it. I have some questions about cooling though. What is considered a "normal" temp range?? 210-220? Lower? Higher? Here's why I'm asking... I had a local shop who sells remanufactured engines re build my 4.0 (long block). I finally got it back in and its been running a bit warm. I'll go drive it for a while (15-20miles) and when I sit and idle for a while, the temp would jump up to about 225-230 and the aux fan would come on. It would take a while to cool down back to about 210 then it would creep back up and just keep cycling like that until I started driving again. When driving at highway speed it would stay well above 210 unless it was raining...then it would drop well below 210. I've got a little less than 1000 miles on it at this point so I've been trying to fix the cooling issues. I started with the easy stuff, doing a chemical flush on the system. This seemed to help but it was still having issues. The coolant that originally came out looked like chocolate milk. I flushed it enough to get to a nice clear green when I drain it now. After doing that, I went to replace the thermostat. Only to find out that I hadn't installed one when I put the front of the motor together :doh: . I got a stock 195degree. That didn't help at all. It now warms up quicker...which is the job of the thermostat. But after it warms up, it doesn't start to cool down until the aux fan comes on. So I started reading forums..... Thats when I decided, it would probably be a good idea to get a new radiator since the original one had that chocolate milk running through it for so long and is probably corroded past the point of no return. And, I might as well get a new fan clutch, since the one I have is as old as the truck (92). So I bought an all aluminum 3 core radiator (and boy is it shiny! :brows: ) along with a brand new zj fan clutch. After an afternoon of squeezing and praying it would all fit, I filled it up and cranked it up. Seemed to work ok. At a cold start, temps get up quick, then I can see when the thermostat opens and the temp gauge drops about 10 degrees really quickly. I go for a drive, it gets to 210 and sticks there while I'm driving. If I stop though, the temp starts to slowly creep up. It takes a while, but eventually, the aux fan comes on to cool it down. When that happens it goes down quickly, then the fan goes off and it slowly creeps back up again. With the new radiator, it holds temp MUCH better while driving, and takes a while to heat up when idling and cools quickly once the fan comes on. Am I missing something? Or is this normal and I'm just being paranoid? Any advice would be helpful. --Additional Info 92 4.0 HO. stock, rebuilt recently. All new sensors including temp. Running "break-in" oil with zinc additive. (to be changed out soon for normal)