ok i took it for a drive the other day drive around for about a half hour turned it off and it started bubbling up then the coolant just poured out came back to it hours later filled it up just to get home it did the same thing i just replaced the thermostat and my water pump is only 5 months old after replacing the thermostat i started it and the coolant got hot after about a minute of running and then just poured out of the overflow and top of radiator i have no idea whats wrong with it and im really just about to sell it even though i dont want to please help

 

What temp thermostat did you get? Thats my first guess. Year of your ride? There are some issues with some year models and making sure you get all the air out of the cooling system. Also, you didnt accidentally "glue" the tstat closed or put it in upside down did you? Thats all I can think of right now since Im at work, but Im sure that there are some others here that can come up with more. Also, try searching "overheating" in the search tab at the top. May be suprised what you can learn from others mistakes...LOL!

 

Dayum, that's one long sentence. LOL. Besides replacing the t-stat (twice????) and the water pump 5 mos ago, have u done anymore cooling system maintenance? Is coolant actually coming out the top of the rad or just the overflow bottle?

 

Could be a few things. You flush your entire system?

 

well, first i would flush the whole system, then refill it. if not. i guess its your a/c compressor or a cracked head big guy

 

If it overheats that much and quik, it must be an big usse!

- Check the cylinder head gaskit. If you see true the oil cap some creamy coffe color "mud" and have bubbels on the did stick or oel in the coolent, it is an good indication.

- Flush your system and radiator

- Check the fans and the fan clutch. electrical fan has to junp in if coolent reaches 218F or AC is on. Start the engine with AC off and see if the E-fan runs, then swich the AC on and see if the fan starts runing. if not--> there is an problem. Check the mechanicl fan clutch. With your engine not runing, your mechanical fan should be so easy to rotate.

- If all of this seams to be ok, change the waterpump and thermostat.

 

Radiator and radiator CAP are suspect.

Be sure both fans (efan and fan clutch) are working

Be sure serpentine belt is tight and powering your water pump properly

 

One thing I've always done is loop the heater hoses and take out the thermostat. This will at least tell you if u have a blockage in one of the head jackets.

 

leak down test? someone else can elaborate, but I think this will tell you if you have a leak in your cyl head gasket, and more so. Just one more way to help narrow down where the problem is.

 

Off the top of my head I would say either air in the system, a clog somewhere, or that water pump is defective.

 

Interesting, how does this tell if a jacket is clogged? Not going to hijack, but I'm having a problem with overheating and no heat. T stat is out as of right now, head just came back from machine shop, all good, still overheating though.

 

You my friend should remove your water pump and check the 'fins' I would bet if its not a new pump then your fins are rusted off -

But to answer your ? it is simple really. Looping and removing t-stat is just a starting point of trying to narrow down the problem. If there are still overheating issues after you have removed t-stat and looped the heater core hoses, then the only applicable solution is a blockage or improper workings elsewhere. You have essentially eliminated items (h-core and t-stat) to help narrow down your problem, period. Removing and looping is not going to produce the genie that tells your where the problem. By removing and looping this leaves the rad, internal cooling jackets, and water pump to be diagnosed. I am assuming you have already checked the hoses, if not I apologize for assuming. Give'em a good squeeze, if they squeeze very easily and are spongy then your hoses are collapsing when hot fluid is going through - replace em. If they crack and break you need new ones anyways. If you have never replaced them, then what are you waiting for...to overheat.

If the rad is new (I think the OP said his was) and water pump looks good internally...then the only other thing is a blockage - inside the motor - ta-daa water jackets. Again this just helped me narrow down my problem....which turned out to be the water pump fins had completely rusted off internally...it was basically a big 'washer' spinning and not ever pumping any fluid.

Also FYI - there is a coolant drain plug on the motor....not a freeze plug but a drain. If I remember right it is on the dr. side of the motor. I flushed and flushed my system when I was having problems. A fellow xj friend informed me about that plug and when I took it off thick chunky shet drained out that never flushed out on the earlier flushings. Don't forget that plug when you flush. And CLR is your friend, just don't let it sit for too long, it will oxidize the alum. Youtube jeep clr flush...did wonders for my heater core.

 

Could it be a colapsing bottom radiator hose?

 

If its not a head gasket its is prob a radiator cap. It holds pressure, if it doesn hold pressure, it will spew out the top and the overflow. And just like a pressure cooker that isent working, the coolant will boil at a much much lower temp. relplace the rad cap, and report back. A simple, and often overlooked fix.