persnickety

Driving home this morning coolant spewed from I think the sprung cap valve. The temp gauge never read higher than 220, which is a tiny bit hotter than usual, but not extreme. After the spew the temp read about 230 until I got home. I couldn't look at it too much until tonight.

Started up the jeep to let it warm up. Waited 10 minutes, temp gauge didn't budge. I figured I mistimed it and headed out. Within a minute or so the temp ran up to about 230 and I turned on the heater to cold air. I got home, turned it off and I can hear wet air leaking from somewhere. The top radiator hose is soft.

I'm assuming there's an air pocket in there. Right? So I'll try burping.
Anything else I should check for?
What made the valve go?
I need to get to and from work, 15 miles each way at highway speeds, through tuesday.

It had a dexcool mud problem when I bought it used, so I've had the radiator flushed a few times in the last 5 years trying to clear it up. The last coolant change was last spring. I've had some weird temp issues on and off, but nothing my mechanic is ever worried about.

VTJeep

Hmm. Clog in system or tstat sticking closed maybe..

djb383

Need to find a new mechanic ASAP.....tell him/her what u just told us....the leak needs to be found/fixed ASAP or u will be on foot.

persnickety

Alright. I checked out youtube for how to burp the radiator, and I basically take the cap off, top off the coolant, turn it on, let it idle, and top off the coolant until it overflows? Is that correct for a 1999?

djb383

Have u determined the fix for this problem 1st?


After that, install a new rad cap.

persnickety

No, I have no idea what caused the first problem. It'll have to wait until monday when my mechanic opens. For now i just need to be able to limp to and from work. Monday morning it'll be dropped off until things are figured out.

RTorrez1

Yeah!!! Of course he's not worried about it because he has you coming back for the same problem and maybe one day for a major repair from over heating you engine. I would find another mechanic that you can trust!

persnickety

I put in 3/4 a gallon of 50/50 mix-with-any-color coolant (what I had on hand) and ran it into town (to get more coolant) and it was alright for the most part. I'll top it off before I head to work and I'll look for another mechanic in the mean time. I picked up a new radiator cap too, I just took the one the computer told the counter guy what would fit. Is there much of a difference offered in radiator caps?

RTorrez1

If I am not mistaken the rad cap should be a 16lbs without the pressure relief handle.

djb383

If u must continue driving before correcting the problem, I'd suggest carrying a couple gals. of water with u at all times just in case.

Jesse Hallum

Ah yes, DeathCool and the mud; wild temp readings; spewing coolant and a heater that won't work properly.

Fire your mechanic immediately.

Your cooling system is clogged up with DeathCool garbage. I've seen it 1,000 times. The only cure I've ever seen that worked was replacement of the water pump, heater core, radiator, OEM thermostat and all hoses, followed by an acid flush of the block and a 50/50 mix of distilled water and G-05 coolant, along with the strict adoption of a 2-year coolant replacement schedule.

Stacy's Cherokee Sport had this same, exact problem when she bought it. The prior owner was an idiot. He not only put in DeathCool, but ignored a leak in the rear differential cover, which led to the complete destruction of the gears and axle bearings. There are people who are too stupid to live on this planet.

I replaced all of the above and paid a decent shop $1200 to completely rebuild the rear end. Several years later, it still runs like new and as long as I suck wind, it will continue to do so.

In your case, the outcome rests on the size of your wallet, I guess. Dex-Cool should never be added to an automotive cooling system, in my not-so-humble opinion.

persnickety

I burped it again before I left for work...or tried to anyway. I topped it off with coolant as it warmed up (about a 1/3 gallon of 50/50) and as it got warmer the coolant sort of steadily rose until it was slowly flowing out of the radiator cape pipe. There was a steady trickle (I caught it all in an old oil catch pan and soaked it up with cat litter and bagged it up) until the dash temp gauge read 210 and the coolant level suddenly dropped. I topped it up some more and it surged up and down a bit before slowly rising again and steadily flowing over and out. I didn't get any bubbles like I saw in the youtube videos I watched. I got to and from work with no problem. The heater was working great, temp didn't read over 210.

Is the flowing over part normal? If not, what was happening? I'll be taking it to a shop recommended by a coworker on monday, so I guess I learn one way or another then, but I'm curious now and monday is so far away haha. Any ideas?

Oh, and thanks for all responses so far. This is a great forum.

djb383

R u saying coolant is leaking out when the rad cap is on? Have u installed a new rad cap? If coolant leaks out around a good rad cap, then most likely the neck of the rad is cracked requiring rad replacement.

PocketsEmpty

If you got the death mud in your system, better get your wallet ready and start replacing everything. My XJ was also a victim of this. I had to replace the radiator, hoses and freeze plugs on the engine and also the thermostat (the water pump is kind of new). It was a lot of work, and so far it is running great and staying cool since that work was done. The last remaining victim? .. the heater core. If your heat isn't working, you can backflush the core and it may help. It made a world of difference in mine but mine still has a leak somewhere--I can smell it when I first start up with the defrost on.

Sounds like a good start for your situation would be a rad replacement altogether. It's not too hard to replace--but you can forget about the drain plug on the bottom of the radiator. It's easier just to pull the lower hose from the water pump.

Good luck

Green & Yellow

I had the same thing happen to my 93' XJ and it ended up being the heater valve. The little rubber boot that connects to it came unplugged, closing the valve. This would affect the heater inside the Jeep, not allowing the warm coolant to pass through if I am correct. I also had the same symptoms, coolant temp reached about 230-240 and spewed out my radiator cap. I learned the hard way, I bought a new radiator (didn't install it) and figured out it was something that simple, I replaced my heater valve since it had a hairline crack in it ($25 fix). If you don't know where the heater valve is it is right above and to the left a little of your oil dip stick, it has 4 larger coolant lines attached to it and the rubber boot should be on the top side. It's worth a shot in the dark, it is a no cost fix if that is your problem and it (the rubber boot) easily can come unplugged when you check the oil.