My 94 xj is over heating at idle and driving. Over heated on the trails on a nice 95 degree day. Since then always wants yup over heat. Found a small leak in hose, replaced it, still over heats.

When parked on garage. Start it up. Instantly coolant stats to over flow out radiator. Every few minutes air bubbles come out but coolant level don't drop. All hoses are hot. So thinking tstat ok(but got new anyway) going to instal that a94 new water pump tonight. coolant clean. Oil clean.

If I did coolant pressure test, would the pressurw drop if bad head?

Would like to hear every ones opinion on this please

 

Almost forgot, when driving, can put heat on full blast w aux fan on can keep out around 210 220

 

Since you are going to change out the water pump and t-stat you should do a complete cooling system flush. When you pick up the t-stat did you get a 195deg. That is the recommended temp. Also check your fan clutch. The fan clutch is one of the main causes of over heating at an ideal along with the e fan not kicking on.
Keep us posted on the out come.
Good luck.

 

no got a fail safe 180 tstat. Def fresh coolant. I never reuse fluids. How do you check fan clutch. Never had to check one before, never had one fail on me and this my 12th vehicle. Me e fan works, wired secondary switch for it.

 

Bubbles in coolant usually indicate blown head gasket or cracked head on the combustion chamber side.

Bubbles + overheating together are usually bad news.

 

If the air burbs (bubbles) were from a blown head gasket, wouldn't the bubbles start right away with exhaust smoke or exhaust smell.

 

http://www.sjdiscounttools.com/lis75500.html

LISLE 75500 - COMBUSTION LEAK DETECTOR

 

not true,but bubbles going into coolant bottles never good sign have system pressure checked including cap, see what happens ...then test for exhaust in coolant...

 

Been thinking about my xj all day. Dont remember for sure, buy sony think the e fan came on by itself. I have been controlling it. But have it setup so it still operates like it should but dont remember it kicking on yesterday

 

Not necessarily. In your case they are blowing into the cooling system.

As Freegdr says, have your coolant checked for exhaust gasses or combustion gasses. It sounds like everything else is OK on your cooling system.

 

Ok fellas, thanks for all your input and opinions. I went with gut feeling and swapped out fan clutch and re bled my cooling system. Let sit in drive never went above 210. Took it for a ride, went and sat at the longest light ever made and never went above 210..... Had the heater on cold and no e fan.

So thanks again!

 

That's great if it really fixed it.

But why did it blow out coolant from a cold start, and have bubbles in the system, as you said earlier? A bad fan clutch wouldn't do that.

 

No but when over heated could of got air into the system or the over over heating could of been vapor lock. But clutch def no good stopped with a rolled up newspaper. New one shredded it. Drive it again, no problems. Going to drive it tomorrow and find out

 

Dropping