XJ running very warm. Please help!!

[lbsnowryder]

Have you burrbed the system good? I pulled mine up on ramps and let it run with the cap off until the T-stat opened. Filling everytime it dropped I repeated for about 30 minutes. Be aware this will make a mess and your neighbors might not like it.
If it still overheats the radiator is the last thing to purchase and unfortunatly the most expensive. I droped the money for the 3-row as well. It did the trick and now i wonder if all the other stuff was needed at all.

Keep us updated. I had help so now i'm willing to offer mine.

 

[Blaine B.]

Dunno, I could try that. You had the front end up on the ramps, right? Makes sense......air will be at the highest point which is the cap area, lol.

I dunno, I got the radiator from AutoZone. Put it in last July. Like I said it was fine all last summer/fall/winter until about late March of this year.

Just went wheeling today. Temp fluctuated.....would go below 210, then would go above - about half way between 210 and 225. I was flooring it up a sandy hill and it was still below 225.

Although the entire way home on the highway it was still sitting half way between 210 and 225! I thought on the highway it's supposed to go down.

BTW, I have a pushbumper and 4 lights infront of my grille. I had the same amount of lights last year though, so I don't think that's the problem. I also have sprayed out the new radiator to make sure the fins were clean a few weeks ago.

Here's a pic of my front end. Like I said, there were no problems with everything that is there last year.....thanks for replying!

(PS mine's the black XJ on the left)

 

[Blaine B.]

Oh by the way, one day I had the entire bumper off including push bumper and lights (got a new bumper, had to paint it)

The temp was still higher.....so I guess that right there proves the guard/lights aren't to blame. Plus I was on the highway a few weeks ago and it stayed below 210 for an entire 2 hours. Thanks again. Seems to fluctuate alot, which is confusing.

 

[Blaine B.]

I noticed something else.

Temp will fluctuate......below 210, above 210, etc.

But if I floor it for a short while - like maybe two minutes later, the engine temp will start to climb - just shy of redzone.

Anybody have any idea why?

 

[RaccoonJoe]

Is the aux fan working properly?? I noticed that mine wasn't turning on like it should.....Now I just flip on the defroster when the temps start to rise.

The only other thing I can think of is possibly another bad sensor. Have you tried sticking an aftermarket temp gauge/infared heat gun to it??

 

[fubar XJ]

Go with a three core rad and high flow water pump.

 

[Blaine B.]

Aux fan is working. It almost runs all of the time now. I was getting into mid-redzone just driving around town. It is about 89-90 degrees today (Farenheit)

I have not tried using a temp gauge yet. I will perhaps be able to use a contact thermometer - but I'd have to buy a lazer thermometer if I wanted to use one of those.

I understand that a three core radiator and a high flow water pump would keep my rig the coolest - but, the setup I am running now worked last summer. So rather than try and cover up a problem, I'd rather find the cause. Although things aren't looking good since just about everything has been replaced/looked into already.

 

[Ecomike]

Over the years when ever I had a slowly rising SOMETIMES temperature problem like yours it was always a very tiny antifreeze leak, a not quite tight enough hose clamp, or very tiny, self sealing radiator hole that SOMETIMES leaked just enough to slowly let the system loose some pressure causing the system temperature to climb. They were very difficult to find as the leaks evaporated and never dripped. And it took weeks to notice (measure) the coolant looses.

Is your system open? If so I would try a few different radiator caps, I have seen a lot of bad radiator caps on the store shelves lately.

If you have the closed system, check the seal surface on the plastic bottle and try a new cap, maybe even a new bottle it the cap seal area is not flat and smooth.

 

[Blaine B.]

I have the closed system. I did try another cap.

We also pressure tested the system. It held pressure, minus the stupid gasket on the tester nozzle.

If my system was leaking pressure - wouldn't the amount of coolant in the overflow bottle increase? Perhaps not, I'm not sure......it would if the pressure leak was the radiator cap, but besides that, I'm not sure.

I'll be able to use the contact thermometer tomorrow. I'll test it when it's registering warmer than usual and see if I can't get it back into the redzone and then read it again!

Thanks!

 

[Ecomike]

A friend of mine calls them Morphiedite (sp?) systems, as they do not follow logic and they do not follow the normal physical laws of physics or the universe.

If the leak is leaking only tiny amounts of liquid at a not quite tight enough hose clamp, or a spot deep inside the radiator core (not visible), the bottle volume would not change, but the pressure and temperature would. Also radiator and system pressure tests are nomally done at ambient conditions, not while driving, and not while the engine is running. They are typically a static test so they could miss a hot operating, intermitent, sometimes self sealing leak. Keep in mind that one of the ingredients in antifreeze is designed to dry and seal very tiny pin hole leaks as it leaks out of the very tiny pin hole.

Can you run the pressure test on the system itself, and run it while running the engine? If so I would try that, then stick it in drive with the A/C running and the parking brake on while idling and watch to see if the pressure drops a little everytime the temperature spikes or eases up some suddenly.

Perhaps the sealing surface on the bottle, that the cap seals on is not sealing perfectly (I doubt this one as would expect to see the liquid volume in the bottle increase as you pointed out, but offer it as possibility).

Be sure and use the temperature tester to look for hot spots and temperature gradients in the engine and the radiator.

I have the closed system. I did try another cap.

We also pressure tested the system. It held pressure, minus the stupid gasket on the tester nozzle.

If my system was leaking pressure - wouldn't the amount of coolant in the overflow bottle increase? Perhaps not, I'm not sure......it would if the pressure leak was the radiator cap, but besides that, I'm not sure.

I'll be able to use the contact thermometer tomorrow. I'll test it when it's registering warmer than usual and see if I can't get it back into the redzone and then read it again!

Thanks!

 

[Blaine B.]

Hm, it's possible the AutoZone crap radiator could have a tiny hole, like you said (something unseen)

I'll let you know the temp results. I never even used a contact thermometer before. From the looks of it (google images), it looks like something the nurse in elementary school used in people's mouths lol.

 

[Ecomike]

Hm, it's possible the AutoZone crap radiator could have a tiny hole, like you said (something unseen)

I'll let you know the temp results. I never even used a contact thermometer before. From the looks of it (google images), it looks like something the nurse in elementary school used in people's mouths lol.

I have both kinds, contact and infrared, I am hooked on the IR ones. I got a mini IR one from Harbour Freight (HF) for $20 on sale back in march. They had a sidewalk sale here this past weekend and were selling them (the mini IR) for $13.95.

What I like about the HF mini IR unit is they can get into tight spots, are easy to aim and read, and they are extremly acurate. The price is incredible.

I can aim it at spots as small as 1/8" and get temperature data on the head temperature 1/8" from the exhaust manifold with out even touching it (OUCH!)

 

[Blaine B.]

There's a local harbor freight but I've never been there! Will have to go. Never hear much about them though. It's right next to Hooters

 

[Ecomike]

There's a local harbor freight but I've never been there! Will have to go. Never hear much about them though. It's right next to Hooters

Even more reason to go, but I must warn you, it is habit forming!:shiver:

HF that is!

They have got lots of very inexpensive (relatively speaking) mechanics tools and gadgets!

 

[Blaine B.]

Yes yes, I hear the cheap stuff breaks tho.

I shop at AutoZone for important components in my vehicle too, so I'm one to talk lol.

 

[Ecomike]

Yes yes, I hear the cheap stuff breaks tho.

I shop at AutoZone for important components in my vehicle too, so I'm one to talk lol.

Two schools of thought on cheap stuff. If I am buying a tool that will get used once or twice, or once a year, once every ten years, or once before it gets lost :tears: due to lack of use, then cheap is good for most items like tools.

If it is a tool that will get heavy dialy use, then it becomes a maybe issue depending on the cost difference, actual individual tool qulaity and servicability.

I have great luck, less than 1% failure, returns, with most every part I have ever bought from Autozone for at least 15 years.

 

[Blaine B.]

True, I've never had any problems with autozone (so far) besides their thermostats and brake pads.

 

[Blaine B.]

Well, using the contact thermometer today-

As the engine read above 210, the thermometer actually read around 180 or so as we probed various hoses, as well as the thermostat housing.

Now understand this is the temperature of the metal, not actually the coolant....so.....I'd assume it's a close reading, but perhps add another 10 degrees or so?

It was also suggested to me that my Dexron III smelled burnt. I did drain the pan twice, but it was suggested that I get the system completely flushed (one of those machines that drains the old and fills the new until it's completely full with new Dexron III).

Something about maybe the trans fluid is getting really hot due to its nastyness and is actually heating my coolant as it flows through the radiator and such. I do have an aux cooler as well. Since I do seem to have problems with the temp on the highway and such when there's increasd speed and such.

It appears my gauge is off though as well. By maybe 20-30 degrees?

Thanks!

 

[outlander]

Did you ever think about getting yourself a cheap temp gauge and installing it in the cab so you can compare the stock gauge to the new gauge?This is what I did....the stock gauge(on the closed system) is in the head.I installed my aftermarket gauge probe into one of the block drain bungs.I have noticed about a 5-10* degree difference in the two....I tend to trust what the new gauge says over the stocker.

I also highly recommend an open conversion like the one I outlined here:
http://www.naxja.org/forum/showthread.php?t=920779&highlight=poor+mans+cooling+conversion


Before I did this conversion I always ran hot.I replaced all the cooling parts Like you did and still ran hot.Did the conversion and all is good....there are a few beleivers in the closed system,I am not one of them.My problem was the surge tank.Couldn't really tell because the leak was small.....

The good thing about this way of doing the conversion is it allows you to keep your new(closed system) radiator that you bout recently and only costs about $40.00 total,so why not give it a shot???

 

[TMXONR]

I just installed a gauge cluster so I can see what my temp is at. I am using the Wells temp sensor from AutoZone. I drove the Jeep today to check everything out. My gauge is reading from between the 210 line and the line after it which I calculated to be 235. I stoped at Sonic on the way home today and left the engine running with the AC on and the gauge went to the 235 line and stayed there, on the way home it looked like it went down about 5 degrees. When I got home the hood and the piece with the JEEP emblem on it was cooler than it was when I was having hose and resivor problems. Could it be the Autozone sensor. How much is the sensor from the Dealer, I don't remember seeing it posted.

Oh yea, 1987, closed system, 4.0
Here is a pic of my bumper set up, today I had the cover on the winch. I am going to run with out the cover on Sunday to see if that makes a difference.