2001 TJ SE Overheating

[Chitoddy]

At the beginning of the summer (early June) my 2001 TJ SE overheated driving on the city streets after like 15 min. Took it in and they replaced the radiator. It's been fine since including some hour or so jaunts on the interstate - until today.

Today I was driving from Chicago to Indianapolis and about 2.5 hours in the AC went from blowing cold to moist warm humid air. I looked down and the temp was in the red but not all the way to the right. Pulled off when I could and ran the heat for a bit and then turned it off and let it cool down a few. Decided to make an effort to drive the rest of the way on country roads at 55 with A/C off and temp stayed at what I consider normal temp (just under the 210 mark) and I was able to make it to destination.

This morning I had an oil change before leaving and had all the fluids checked. Double checked when I pulled off and the coolant tub is definitely above full.

Any idea what could be causing this? They showed me the air filter at the oil change and it looked good to me - a lot of white still. I think it was changed when I took it in for the radiator but don't know for sure. Should I get it rechecked?

I saw in another thread that someone suggested checking the coolant in the radiator, especially if the radiator was replaced recently. should I do this? Is that looking (after it cools down fully) in the silver cap that I know you're not supposed to open when hot? How do I tell if its full or needs more? I'm not very mechanically inclined so I would have assumed that if the coolant tub was full the radiator would have what it needed?

Any insights would be appreciated. Did having the A/C off for the rest of the drive make the difference some how?

Tomorrow I need to try to get back to Chicago and if need be then get it in for service; even if it means taking the long slow way home.

Thank in advance.

 

[Chitoddy]

Update: Drove home from Indy to Chicago today. Left early to beat some of the heat. Drove the reverse I did on Friday. 55mph back roads for an hour - no overheat. Got on the interstate was good for about 2 hours until i was just outside of Chicago and noticed the temp started pushing up slowly. Was just hovering past the 210 for a bit then when I was about 5 miles from home it shot up to 260+ again. Also noticed the car started driving more sluggishly as I approached the city. As soon as I pulled off and slowed down the temp dropped back to around 210 and stayed there until I got home on city streets. Very weird. I will note that by the time I was getting to the city the outside temp was 20 degrees hotter than when I left.

 

[pagrey]

It's possible you've got a leak somewhere in the system. You might pressure test it and go from there, at least that's where I'd start if I couldn't see anything obviously leaking in the engine compartment. You don't smell coolant with the heater running do you?

 

[Chitoddy]

It's possible you've got a leak somewhere in the system. You might pressure test it and go from there, at least that's where I'd start if I couldn't see anything obviously leaking in the engine compartment. You don't smell coolant with the heater running do you?

Not that I've noticed - but I was running the heat with the windows all off and not really paying attention. It'd smell sweet?

 

[pagrey]

Ya, sweet and like coolant. I ask because you mentioned hot and humid but the A/C was probably just struggling. I'd replace the radiator cap first, cheap and good insurance even if yours is fairly new. It can cause this, especially a high overflow tank. Your system sounds like it's just at the tipping point and there are allot of things that can go wrong to cause it. Leaks is a good place to start, after the cap.

 

[Chitoddy]

Ya, sweet and like coolant. I ask because you mentioned hot and humid but the A/C was probably just struggling. I'd replace the radiator cap first, cheap and good insurance even if yours is fairly new. It can cause this, especially a high overflow tank. Your system sounds like it's just at the tipping point and there are allot of things that can go wrong to cause it. Leaks is a good place to start, after the cap.

Thanks for the feedback - I can look into that. My concern is having to drive 2 hours to find out if it overheats again if I just change the cap? Seeing as I'm not adept to test for leaks myself I guess I'm going to have to take it back in to the shop and just go over what's been happening.

 

[pagrey]

After the Jeep completely cools off remove the main silver radiator cap. If the level is low in the radiator the cap is almost certainly bad and your problem. If the radiator is full then replace the cap and gamble or take it to the shop and let them have at it. Pressure testing isn't bad, most auto parts stores will rent the tester but I can understand not wanting to jump in both feet first.

 

[Chitoddy]

After the Jeep completely cools off remove the main silver radiator cap. If the level is low in the radiator the cap is almost certainly bad and your problem. If the radiator is full then replace the cap and gamble or take it to the shop and let them have at it. Pressure testing isn't bad, most auto parts stores will rent the tester but I can understand not wanting to jump in both feet first.

Thanks for the step through. If it is in fact low - do I need to also fill it? And define low - should it be to near the top?

 

[pagrey]

Yep. If it is operating normally when the engine cools it should draw coolant from the overflow back into the radiator if there was any missing. If the radiator is low that means that either the cap is busted or there is a big enough leak in the cooling system it isn't able to pull coolant back from the overflow.

 

[Chitoddy]

Yep. If it is operating normally when the engine cools it should draw coolant from the overflow back into the radiator if there was any missing. If the radiator is low that means that either the cap is busted or there is a big enough leak in the cooling system it isn't able to pull coolant back from the overflow.

 

[pagrey]

That's full for sure, is that the same color as the overflow? I'd think it'd be green or gold if it's been changed recently. Maybe somebody else will chime in but that's some pretty deep red there if it was just changed out.

 

[pagrey]

Oh, and in the picture the cap is f**ked. That little bottom part is supposed to be tight up with a spring and yours is busted.

If this part isn't pulled tight against the rubber gasket with a spring it wont work and might cause some of your issues.

 

[Chitoddy]

Oh, and in the picture the cap is f**ked. That little bottom part is supposed to be tight up with a spring and yours is busted.

That's full for sure, is that the same color as the overflow? I'd think it'd be green or gold if it's been changed recently. Maybe somebody else will chime in but that's some pretty deep red there if it was just changed out.

Now I could swear that yesterday when I pulled over after it first overheated on the way to Indy that the overflow was fairly full and looking very greenish in the daylight. But I just went back down and took a picture (i'm in a dark garage) and illuminated it with a light and this is what it looks like:

 

[Chitoddy]

Follow up - took it to a local mechanic and they report thermostat housing needing replacement.

 

[Jerry Bransford]

Follow up - took it to a local mechanic and they report thermostat housing needing replacement.

View attachment 274195

Make sure they know its temperature rating has to be 195 degrees and don't let them install a "fail-safe" model. Fail-safe thermostats like to fail in the open position because they tried too hard to make them not fail in the closed position.

 

[pagrey]

Once you replace the cap and you or they fix that housing if it needs to be done keep a close eye on it. Once it starts holding pressure again things everywhere tend to start leaking. Sounds like you're making progress.

 

[Chitoddy]

Well, had the thermostat housing changed, coolant flushed, etc 2 weeks ago. Was headed on a couple hour trip to Michigan that weekend and 30 minutes on the interstate it overheated again. As soon as I got on non-interstate and drove 40 to 50 mph it dipped down to a manageable temp. I do note that now my temp gauge seems to be showing the average temp around 160 instead of closer to 210 like in the past before any overheating issues. I took it to a place at the end of last week for another opinion. They came at me with that the engine block was likely rusted and there was nothing they could do. Not sure what to do next? The pic below is one they took last week at the second opinion. Is all this rust likely in fact from the engine and I'm a f*cked at this point and would need a new engine? Or are there other things I can try? I assume the radiator I got in June could be f*cked at a minimum? Thoughts on how to proceed next? I'm moving to Denver in a month so right now with the stresses of that I think I can get by with the couple local miles I drive a day and then tow it to Denver and deal with it once I get settled there....

 

[pagrey]

Rust is normal if the coolant has been in there too long. It is nothing to worry about on its own. 160 is wrong, you probably need to replace the thermostat again, it should be at 210 when it is warm. I'm afraid to ask, did you replace the radiator cap?

 

[Chitoddy]

Rust is normal if the coolant has been in there too long. It is nothing to worry about on its own. 160 is wrong, you probably need to replace the thermostat again, it should be at 210 when it is warm. I'm afraid to ask, did you replace the radiator cap?

But if they just did a coolant flush and put new coolant in (assuming they actually did) - should it look this rusty again already 2 weeks later? They should have replaced the cap - but I guess I need to double check it.

 

[pagrey]

They might not have taken time to carefully flush it, who knows? You have some stuff obviously not working right and it's questionable what the shop is really doing if it's running now at 160. I've had a bad thermostat out of the box so it could just be that but if they tested it after fixing it they should have noticed it wasn't working like it should.