Thermostat and Autozone and a Question

[bermeced]

1077176

Well -- my 1980 cj7 was overheating when I stood in traffic. My temp usually stayed around 180, but recently started climbing to over 200 if I stoof for very long in traffic. I decided to go to Autozone to get a gasket -- I decided to take the thermostat out all together. When I got to Autozone to get the gasket, the clerk told me that it would be very bad to run the jeep without a thermostat, so I purchased one from him. I put the new thermostat in and within 10 minutes the temp was well above 200 degrees. I got back home and took it out again -- now the jeep temp hovers around 140 to 160 degrees. My question -- is it "very bad" to run the jeep without a thermostat. I did not think that it was. [addsig]

 

[K_K_PSI_GUY]

1077177

The okay gas mileage will go to the gutter. The computer will have to try to adjust and your Jeep May run rough or different. Go back to autozone and get a lower Temp. Thermostat. I beleive it is 170. That is probably the type of thermostat you had on before. It is better for you to get the thermostat back on there.-Al[addsig]

 

[bermeced]

1077192

Well -- i just put a 160 thermostat in the jeep. Again, it overheated within 5 minutes. Again, when I take it out, everything seems fine. Very puzzling. There are no leaks in the system, there is a new radiator, new water oump, new belts, new hoses -- I cannot figure it out. Let's say that the water pump was a defective one -- would not the jeep still overheat whether the thermostat was in or out, or does taking the thermostat out somehow make the water pump seem ok. I had no serious overheating problems -- just when standing in traffic -- until today, after I put a new water pump in and while I was at it decided to change the thermostat. Does anyone have any ideas??? And finally -- can I use the jeep without a therrmostat, will it damage anything. There seems to be conflicting opinions on this thermostat or no thermostat question.[addsig]

 

[XJNick]

1077196

Have you replaced the fan clutch? The coolant can move faster without a thermostat, so that could help make up for poor air flow caused by a bad fan. Also, maybe there is air stuck in the system. Does your heater work?

I'll agree with those who say you should keep the thermostat in there. It was there for several reasons. In addition to the ones mentioned by K K PSI GUY, the heater will not work good come winter since the engine will be running too cold

edited by: XJNick, Jul 20, 2003 - 10:08 AM[addsig]

 

[bermeced]

1077200

There is no fan clutch. And a friend of mine has a cj5 of the same year and that has no fan clutch, In any case -- I just took a long ride in the jeep and the temp hovered around 160 to 170 -- never climbed any higher. However, I do agree that something must be wrong -- it is puzzling that it runs fine without a thermostat, but that everytime I put a thermostat in the temp zooms to over 200 in less than 5 minutes. ??????
I am not too concerned about the heater -- I live in Florida. I do have a question -- if there is air in the system, how do I check and solve that problem. In any case -- still, my biggest concern is -- does running the jeep with no thermostat harm the engine in any way???[addsig]

 

[K_K_PSI_GUY]

1077204

I don't want to offend you but are you sure you are putting in the thermostat in correctly? That is very strange. Thermostat is suppose to open up at 160 if it is rated at that temp. No fan Clutch? Does your temp. go past 200 degrees? does it "overheat", or is it just a different temperature than usual? -Al[addsig]

 

[bermeced]

1077207

Yes -- the thermostat is in properly. And yes, the whole situation is odd and puzzling. No -- the jeep does not have a fan clutch, and my friend, who has two jeeps -- cj5 and cj7, 1979 and 1980 -- says nether of his jeeps have a fan cluch either, and that none of his previous jeeps had one either -- that it is not unsual that these jeeps have no fan clutch. But, he also has no idea what could be wrong with my jeep. This is just driving me crazy????[addsig]

 

[jay89]

1077280

Some of the t-stats have weep holes that have to be in the correct position. It could be just a matter of repositioning the stat. Are you bleeding the system after you put it in. If you have air in the system it could overheat too. :-? [addsig]

 

[bermeced]

1077318

I don't know how to bleed the system. What should I do to make sure that there is no air in the system? Thanks.[addsig]

 

[Jeepr89]

1077406

Let the jeep warm up with out the radiator cap on and fill slowly and watch and wait till all the bubbles come out, this is how I let the air out of the system.
[addsig]

 

[K_K_PSI_GUY]

1077414

I know how fustrating this can be. My POS Grand Am would overheat on me all the time. It turned out to be the plasstic resevoir that was not functioning properly.

Okay, does your temp go into the "red zone" ? does it overheat according to the gauge? Does the Jeep feel and or sound like it is actually overheating? I've heard of Jeeps having bad gauges, so don't trust it too much. -Al[addsig]

 

[bermeced]

I give up. I have tried everything, and the jeep still overheats.

 

[PASmokeater]

Check all of the hoses.....I used to have an old boat (with twin 318 Chryslers) and had a problem with one constantly over haeting to the point of melting impellers. After two seasons of trying to figure it out, I finally found the problem.

Look to see if the INSIDE of the hose is collapsing. The boat's would collapse on the inside, but to the eye, the outside would look normal.

You can run it up to temp, and lightly touch the hoses. Feel for heat, and then a cool spot right beyond a hot spot...that will be your break down spot.

Does any of this make sense to anyone ?





Rob 8)

 

[pfz111]

Two years ago I had the same problem with my cj5. It took me over a week to solve it, but this is what I did. First, start all over with the thermostat. Get a new one (they are only around 4 bucks) and get a 180 degree one. Autozone will probably tell you it takes a 195 degree, but there are three available, 160, 180, 195. I have tried all three, and the 180 works the best. Next, drill a 3/32 hole in the thermostat, just above the ring of the thermostat and position the thermostat with the hole in the 12 o,clock position ( make sure to hole is on the top). Next, put sealant on the gasket and place it over the thermostat. Then put sealant on the housing and bolt it all back together. Then, slowly fill the radiator until you get to almost the top. Then start the engine and let it warm up, and when the upper hose starts to get warm, continually squeeze it for a while. Then put the radiator cap back on. AND THEN, take a long ride. Your jeep should really get no higher than 180 and it will fluctuate between 160 and 180. Let us know how it all works out for you.

 

[OneBlackTruck]

Berm...

I had the same problem about 3 months ago with my 83 CJ7, 258. I was so P.O.ed that i replaced everything but the radiator to no avail. I even put the new t'stat in a pot of water on the stove with a thermometer to see if it opened at the right temp, and it did. After posting on another board, I got the answer. It needs to be bleeded.

Go to Napa, and buy a "radiator flush kit" (about $5). Basically it is a plastic T that goes into the heater hose. I will explain below.

1. Check the diameter of the heater hose.
2. Go to Napa and buy the correct size "T" and two hose clamps.
3. Drain your coolant enough so it doesn't spill everywhere.
4. Cut the heater hose that comes from the water pump to the heater core ( cut it somewhere in the middle of the hose).
5. Insert the "T" with the clamps.
6. Remove one end of the upper radiator hose and fill the radiator from here until it just starts to run out, and then reattach the hose. Oh yeah, dont forget to close the draincock at the bottom of the radiator(dont ask me how i know)...
7. Remove the "threaded cap" from the "T", and insert a funnel and fill the heater hose with coolant until it is full. Then screw cap back on.
8. After filling, keep the radiator cap off and start the jeep. You should run it for 10-15 minutes while giving it gas every 10 seconds or so.
You should be able to see bubbles come to the top of the radiator cap opening, there probably wont be very many.
9. After doing that take it around the block and see how it is, but after it cools, be sure to check the coolant level as more coolant could be required.

As the for the "T", aka "flush kit", it is nothing more than a plastic T fitting that has garden hose threads so that you can hook up a garden hose in order to flush the system.

I spent a month screwing with this problem until someone shared this information with me. I was skeptical at first, but it hasnt overheated once since then! Sorry to be longwinded, but hope this helps you.

 

[bermeced]

Thanx everyone for all the advice. My jeep finally is running great -- no overheating. I just finished (it is now 3 in the morning) because I have become obsessed with fixing this problem. Because I could not get to any store so late at night, and because I had a thermostat at home already, I opted to use the "drill a hole" and "squeeze the hose" method recommended here -- and IT REALLY works. Again -- thanx to everyone for their suggestions.

 

[Turbogus]

drill a 3/32 hole in the thermostat, just above the ring of the thermostat and position the thermostat with the hole in the 12 o,clock position ( make sure to hole is on the top).

:coolpics: ...would be a welcome addition here, if you have.

 

[mud4feet]

:coolpics: ...would be a welcome addition here, if you have.

pfz111.....Last Activity: 07-25-2003 06:25 PM ..........I think you're out of luck.

 

[superj]

its just a little hole drilled in the part of hte thermostat that doesn't move when it heats up and that hole it on top when you put the thermostat in the housing. alot of newer thermostats come with the hole in them from the factory now also though.

it is letting the bubbles pass through the system so your not getting a air trapped behind the thermostat that isn't hot enough to open the thermostat. that air keeps it from opening and makes your jeep over heat.

 

[jfrabat]

I'll start by saying that I did not read all the posts, so this may have been piinted out already...

Now, to answer your questions:

1. Yes, it is bad to run the Jeep without thermostat. You can do it if there is no other choice (like if it sticks in the closed position in the middle of nowhere), but it is NOT recommended. The reason is that the engine wears faster when cold, and you would be adding more wear to your engine if you do. The engine is designed to run at about 190*, so it operates best when in that general zone. For this same reason, I do not recommend running a 160* thermostat. If your engine runs of a computer, it's even worse, as the computer will operate in start-up mode, and will not calibrate the fuel to reach the correct mixture.

2. If you are overheating ONLY when standing still, the problem is not INSIDE the engine but rather an airflow problem. This means that not enough air is moving through the radiator, and you have to find the cause.

Hope this helps...

Felipe