Help Please-Cooling system

My son has an 89 xj 4.0, auto, closed cooling sytem. Recently it started ovreheating on him so i took a look at it. From a cold start the recovery bottle is half full, but by the time the temp gauge reaches 210 coolant is just pouring out of the top of the recovery bottle. It doesnt seem to be resercullating at all???

the leat expenive thing would be to replace the thermostat. but if the radiator has never been replacsd, it may be clogged. that happened to my 89 a few years ago.

I'd also replace the radiator cap, it actually the cap on the pressure bottle by the firewall. You will have to go to the dealer to get the "cap" you won't find it at a parts store.

You can get a new bottle which includes the cap for $20 from quadratec.com

The plastic bottle is known to warp and crack so replacement is nothing but routine maintenance. Also when filling the bottle you have a post sticking up. The cold level of the coolant should be over the circle but not over the top of the plastic stud.

When you do replace that cap, DO NOT crank it downl you can split the rubber gasket inside and render it just as worthless as the old one.

If the radiator is stock, replace it...it's 15 years old and probably has passages as clogged up as Marlon Brando's arteries. Other thoughts on cooling: http://www.yuccaman.com/jeep/cooling.html

Yucca-Man said:

When you do replace that cap, DO NOT crank it downl you can split the rubber gasket inside and render it just as worthless as the old one.

If the radiator is stock, replace it...it's 15 years old and probably has passages as clogged up as Marlon Brando's arteries. Other thoughts on cooling: http://www.yuccaman.com/jeep/cooling.html

Click to expand...

I think old marlon's arteries got a good flushing before he was put away in long term underground storage

Another vote for replace the radiator. The original radiator on my '88 sprung a leak in late 1999. When I replaced it I could see that the passges were seriously blockd with mineral deposits, and I'm fairly careful about keeping the coolennd changed. Since the change I use only distilled water.

Also, that bottle is not a "recovery" bottle. It is part of the pressurized cooling system and, as noted by others, if it won't hold pressure the system will likely overheat. I recommend getting a new one from Quadratec to install along with the new radiator. Unless you know that the viscous fan clutch is new, you should also replace that.

Rich - that's the hazards of typing tired...I couldn't think of anyone else likely to have nasty, hardened arteries except maybe the elder senator from Massachusetts...

It already has a new bottle and cap on it that are about a month old. They are from my 90 that just got an open system installed complete.
Can someone tell me which way the water pump works, does it push coolant into the block or pull it from the block.

Digger - there's a pic of it on that link I posted earlier...I didn't dwell on whether it pulls or pushes, just that it works.

id bet the problem is your radiator. my 89 radiator was just declogged last week, which is cheaper than a rebuild or buying one new ($345cdn) at napa here. if boiling coolant is making it out of the overflow tank, than your water pump and thermostat are fine. also ive found that the system is very difficult to bleed the air from. good luck.

Things that cause XJs w/closed cooling system to overheat
AIR in the system,closed system is good for this.Burping the system can be done,and if you ask 10 different people,you'll get 10 different ways of doing it.
Bad pressure bottle,usually leaks where the small fitting is on the drivers side.
The newer type bottles have a piece of metal tubing in the fitting I guess to give it strength.
Pressure cap for the pressure bottle,notorious for leaking,also has a rubber o
ring,once it over heats,yor prolly gonna have to replace it.
Backflushing the system.This is fairly easy to do and should be the first thing
that should be done.Also check all hosees and clamps,heater control valve,
Best thing I have done is swap out the closed for the open system,bout $220.
n coulpa hrs driveway time.Did it last yr,hasn't got past 210 yet

churky89 said:

Best thing I have done is swap out the closed for the open system,bout $220.
n coulpa hrs driveway time.Did it last yr,hasn't got past 210 yet

Click to expand...

How do you convert it to a open system?

Starboard M said:

How do you convert it to a open system?

Click to expand...

These writeups were helpful when I did mine:

http://www.dirtdevils.org/briantechtippage4.htm

http://www.olypen.com/craigh/rad.htm

http://xjnation2.homestead.com/radiatorconversion.html

http://www.off-road.com/jeep/cherokee/98/12_dec/radiator/radiator.html