Sword

Hey guys hope the wizards here can help me out, 96 xj jeep, 4.0 l. I have had a overheating problem, I did a flush and it seemed to have gone away for a little. But I notice my jeep started getting hotter and hotter esp at idle/stops. I reached a critical overheat yesterday while stuck in traffic, it got into/past the red, and got weaker and rapidly my jeep died.

Had to restart and pull over where its currently. When it stopped I saw a bunch of my fluid had boiled out of the cap as well as some white smoke coming from what I think is the engine block.

I bought a new thermostat and also a fan clutch. Anything else? I am worried it is a head gasket, but I have had the smoke before and ended up driving for months after doing the flush.

* Did flush helped only temporarily
*White smoke likely from engine block
*Coolant reservoir is dirty but radiator cap fluid was clean
*I had heat for a little, but near the end tried my heater again and NO heat
*Heats up INCREDIBLY fast yesterday, went from cold to redline in under 2 minutes.
*Also my fan seems to run intermittently, even after going past 210

Thanks if you can help at all.

Sword

Well I slapped a new thermostat in, and I had lost over 2 gallons that I had to replace. I drove the 30miles home and it didnt go above 210, but still not sure that is all there is too it. I still got my new fan clutch, should I change it? (I tried the 'test' of seeing how fast it stops, and it stops right away when power off) Get a new radiator? Can I service my own radiator to clean it up?

BlueRidgeMark

I would do a pressure test to make sure you haven't blown your head gasket or cracked your head, before you put any money into it.

Jakers

^what he said. Also look for a pinhole leak in the rad. I replaced EVERYTHING with the cooling system. Upgraded to ZJ fan clutch as well and was still having overheating issues. Turns out I had a pinhole leak in the rad, not big enough to even need to top off fluid or see any dripping but enough to cause issues. Bought a new rad at napa for $110 and my issues seems to be fixed.

CurrySoSpicy

BlueRidgeMark

Where can I get some of that attetion for my cooling system? I don't think it has any....

CurrySoSpicy

That's my half drunken spelling. lol

Edit: meme fixed! Hoorah!

Sword

Well, so tell me if this is normal guys, I changed the thermostat, full flush, new cap. I routinely run at 210, and stuck in traffic today it was a little higher (almost 1 o'clock) It didn't go higher, but I was surprised it was hanging around here given the stuff I've swapped. Do older jeeps just run this hot? Also, I tried the fan clutch by moving it after running - and it stops in a second or two, which is about right, correct?

BlueRidgeMark

210 is perfectly normal; they are designed to run there.

As to the fan clutch, there's really no reliable test for them. Yes, lots of people say "do this" or "do that", but in the end, it's really almost impossible to say, unless they are either completely free-wheeling, or are frozen solid. Anything in between might be okay, or not okay at all.

That's why most of the old timers just recommend replacing it.

Sword

Is there any way that the fan clutch would be 'half bad' and contributing to my heat? For the record, later today it was cold and raining and I was still at 215ish. Other than fan clutch what else could it be? My jeep never used to run this hot.

TwistedWrench

You mentioned the e-fan was spotty, worth looking into. I say this to everyone, VERIFY TEMPS WITH AN IR GUN. Don't just trust the gauge.

You said you were two gallons low. That's pretty much empty. After refilling, there can still be air trapped that needs to burp out. Also, you may have damaged you water pump. Running it dry, especially at temp, can tear up a water pump pretty quick.

End of the day, as long as she's under 220 you're perfectly in range. She might've been running cooler before due to an incorrect thermostat.

Bryan98XJ

I would look into seeing if the water pump is properly working and make sure the head isnt cracked and the head gasket isnt blown.

Sword

Don't think its a blown head gasket, nothing in the oil. How can I check the water pump and the eletric fan? Also, what about a old clutch fan? (Never replaced mine, had it for 10years)

EZEARL

I'd start out by replacing the fan clutch only for now. Many here including myself have resolved the high coolant temp issue with just a new clutch.

BlueRidgeMark

Agreed! Burp it and put in a new fan clutch, and see where you are. And what Twisted said, too. Verify the temps! Gauges lie! They aren't quite as bad as politicians, but they do lie.

The e-fan can be tested by disconnecting it and running 12v to it. You'll at least know if it's working reliably. Next step is whether it comes on when it's supposed to.

As for checking the water pump... not really. You can get a mechanic's stethoscope (which is a very good thing to have) and listen for bad bearings, but the bearing might be fine yet the fins could be eroded away. No way to check for that except by symptoms, or by pulling it. That's not hard to do, by the way, and they aren't expensive.