Did you talk to me on another board about this? I recall going roundy-rounds with someone else about it recently - with an XJ.

It's vaguely possible you've got another fluke (the three vehicles I've had this happen with were all owned by me - 1980 Honda Accord 1.8L, 1985 Chevvy Cavalier 2.8L, and 1988 Jeep Cherokee 4.0L,) but do make sure you exhaust all other options before you decide to do this. As mentioned above, AMC walked a pretty fine line with the 242ci six when they did the cooling system. It's not inconceivable that there's another one out there that doesn't like having a thermostat (even in subzero weather, Beck heats up just fine! Go figure...) but don't take it as a solution until you've exhausted everything else.

I even tried running a restrictor plate in Beck - and I ended up tossing the plate in the bin (he'd still overheat with that in place. Not as quickly as with a thermostat, but I was exhausting all options.)

 

The thermostat is there for a purpose. Put it back in and leave it alone. Everyone will be happier.

 

Did you try replacing your radiator cap?

 

i would bet that there are other issues that you have yet to discover. i would get a new rad, replace hoses, and flush the system. i know a dude who thought this was a good idea and he bought a new motor not long after.

 

first off, I don't have a radiator cap, I have a resivour. ok, it has a new radiator, new water pump, flushed the system, and still had problems. I took out the t-stat and it runs between 200-210. So my problem is fixed. Sorry if I come off rude, but it runs better like this, and I will run it till I notice issues. I did move the radiator forward about 2 or 3 inches and eliminated the a/c condenser. It will allow it to be a little farther away from the hot enigine. It stays cool and in normal operating temp.

 

explains everything. switch over to the radiator cap system instead of closed and i bet with the thermostat in you will run between 200-210. I myself would never run my jeep without a t stat. wait until your stuck in traffic on a 100 plus degree day and your jeep starts to get hot and your radiator blows up or your resovoir. ask me how i know?

 

An air pocket in that earlier style cooling system is very common and can be a PITA to get rid of sometimes. Does the thermostat you had installed have a air escape at the one edge(maybe has a BB inside)? And was it installed at 12 o'clock?

Also, by moving the radiator 2-3 inches forward you effectively made the clutch fan less effective. It's a puller type fan to pull the air through the radiator. Less airflow means higher temps. I'm also betting your not using a fan shroud.

Were not trying to give you a hard time here, but the "fix" you did by eliminating the thermostat is a band-aid at best. Were just trying to assist you in fixing or finding the problem and fixing it ciorrectly. After all thats why the forum is here and why you created the thread asking for input.

Run it as is but keep looking for the actual problem and attempt to remedy it.

Best of luck.

 

You actually do have a 'radiator cap' - it's just not on the radiator. The black cap on the "football" tank is constructed with a pressure valve - just like older radiator caps (it's just a pressure release/control valve, and not a pressure release/control valve coupled with a vacuum return valve like modern radiator caps.)

@98XJSETH - Bear in mind that there is nothing intrinsically wrong with the earlier "closed" cooling system. My RENIX XJ's are not the first vehicle I've owned with that type of cooling system (and the other ones I'd had were actually newer, oddly enough.) I've spent plenty of time talking with the Jeep wrenches at the local, and the only problem they've seen with it is that the OEM radiators tend to start to clog up somewhere around 150-180Kmiles. Replace the radiator with a quality aftermarket unit (CSF or Modine, usually, but Performance radiator isn't bad either) and go on your merry way. Keep the thing flushed out just like you would with any other cooling system - every two years, and then new coolant mix (old coolant can be taken to a local radiator shop for disposal. Also, check with your local water company for "drain rules" - out here, for instance, small quantities of coolant can actually be poured down the drain and the water company can handle it. But, I usually take a full drain to the radiator shop for recycling.)

Most people who report good results with the conversion usually needed a new radiator anyhow - and what's the first thing that gets changed?

I've had five RENIX XJs so far, and one was converted when I bought it. Oddly enough, it was the one that ran the hottest out of the five (210-215*F at op temp,) and I was seriously considering switching it back. The other four I've been able to keep down around 195-205*F, and I'm experimenting with my 88 (I've pulled it down to ~190*F with no engine trouble, an actual decrease in tailpipe emissions, and a little more room between "operating temperature" and "boiling out at STP". I just don't like running that hot.

OBD doesn't like the temperature being pulled down, OBD-I may throw a code on you (and OBD-II sure as Hell will.) But, RENIX doesn't really care.

 

i had a bad cylinder in mine so i took the rod and piston out and filled it with concrete..... dont rig it. youll be glad you fix it right sometime.



listen technically like everyones allready said its not the smart thing to do. the best thing to do is to figure out whats really wrong with the cooling system. mine did same...i put in new tsat and it ran g=hotter, bought anotherine and it ran fine....had this jeep i got now, it ended up just neeeding a fresh coolant flush. mine was brown and clear. now it runs 220 no matter how hard i push it on those slow creepy trails.

 

ok, well I am junking the jeep today, so we all will sleep better tonight. lol, thanks for the input, now I am looking for something else to drive. I have had too many headaches with this jeep and can't no longer afford to keep fixing it. I will count my loss and learn from my mistakes!! thanks

 

Thats one way to handle it...

 

Living in Phoenix Arizona w/summer time temps over 110-115 & road temps over 150 degrees 3 months out of the year.. Heck We start our jeeps up for the first time in the morning & our engine temp is allready at 100

New radiator not that expensive Hesco 3 core all metal $150 (got to know were to buy it for this $)

Go with a good after market water pump not from your local part store (Hesco)

replace radiator hose's BRX silicone (make sure the bottom hose is not colapsing)

Have the RIGHT coolant mixture all ways use distilled water to delute

Install tranny cooler takes stress off radiator

Make sure the gauge is reading correct your sensor is near the 6 cyl can give you false readings

 

With a factory-type thermostat, mine runs just shy of 210 with a/c on or off--probably around 200 with a 195 t-stat.

 

Junking or selling?

 

I bought my wife a 94 with the 6 in it..fairly nice jeep..paint sux..interior needs replaced but motor runs like a raped ape...tranny is great and transfer works perfectly...my only issue is that during the warmer months..ambient temp above 85..it tends to run over 225 degrees..approaching the too late to stop line on the gauge...i flushed it..have molested 3 different therm stats..installed a 2200 cfm electric fan...took the therm stat out..but she wants to run warm..would I be better for the wear if i were to find and install a 2-core? I put my mini cam into both ends of the radiator and it looks very clean..btw...the pump isant leaking or squealing so i see no need to replace it..it has been replaced within the last couple of years anyway...