Overheating issue

[rockkrawler01]

I have a 1990 Xj. Recently I have changed out the radiator, and the thermostat. But I still seem to be having this overheating issue. My overflow bottle seems to boil over everytime I stop driving. I park and walk around and there is alot of antifreeze on the ground.
My temperature gauge never acceeded 210. Been staying pretty low since i changed out the radiator. But I still seem to be boiling over in the overflow tank.
What else could be my issue?

 

[iamsparticus]

Stuck thermostat is my best guess, or you dont have enough anti freeze and too much water. Did you have the air vaccumed out after the install? If not the air bubbles can cause this, when it gets hot use a heavy rag to let air and steam out of the radiator to burp it if it dosent go away you might want to just replace the thermostat

 

[Bart]

You have two things still to check. First, your clutch fan. If you're still having problems after that, then maybe your overflow bottle isn't sealing or has sprung a leak. I'd replace that.

 

[DOSS]

I would say since you have overheated a number of times anyhow just replace the thermostat.. they are cheap. Then Make sure your fan is actually spinning at speed and not slipping on its thermal clutch (I would just weld it up if it was me). Renix sucks to get air bubbles out of so air bubbles are a good option.. you have a sealed system and I can't remember off the top of my head how to burp that system....

Edit: Bart must Type Faster than me..

 

[rockkrawler01]

When I changed the radiator, I took out the new thermostat that I had put in there. and saw that it is open. Its not a top fill radiator, so all the air bubble would have came from the overflow tank. Ran it for a while to try and get them all out. But I believe I do have some little cracks in the overflow bottle and the cap which dont hold 100% pressure.

 

[DOSS]

When I changed the radiator, I took out the new thermostat that I had put in there. and saw that it is open. Its not a top fill radiator, so all the air bubble would have came from the overflow tank. Ran it for a while to try and get them all out. But I believe I do have some little cracks in the overflow bottle and the cap which dont hold 100% pressure.

if it won't hold pressure on a sealed system that can be a huge issue.. JB weld is your friend

 

[rockkrawler01]

makes perfect sense.. I dont know why I couldnt put 2 and 2 together..

 

[JoeT]

Check out www.madxj.com, I did a writeup there on a cheap way to convert a closed system to a open system, it's under the engine section.

 

[Will3161]

replace your overflow bottle and cap, (VERY important on the closed system: lack of pressure caused it to boil over sooner than it would other wise; that is probably why you don't seem to get to high a temperature, but you get boil over) and there is a plug on the top of your engine, near the back, that is used to bleed all the air out. If I remember correctly, you remove the plug, fill with coolant/water mix till it comes out of the plug, then replace the plug. Also, there is a mod where you drill a small hole in your thermostat to aid in bleeding the system. all in all, converting to an open system is better. the main idea with the open system is that, while it still relies on pressurization to keep from boiling over, it is MUCH easier to get all the air out.

 

[ricsrx]

my problem on my 89 xj was the bottle and cap, once it was replaced..problem solved.

 

[rockkrawler01]

thanks. I did replace it last night. So far so good..

 

[ricsrx]

I had my xj long enough to put over 200K miles on it... it was the most reliable vehicle i have ever owned

I replaced every thing on it 3 times......