98 Wrangler running hot HELP!!

[justjeeping]

My 98 wrangler started running 210 -220 then seemed to shoot to red in seconds! We have replaced thermostat (fail safe 195), fan clutch, radiator cap (18 ) and within the last year waterpump and new radiator. Do I have the right size thermostat and cap? We have "burped" radiator. What else could it be??

 

[mud4feet]

OK...not a mechanic here, just trying to think logically.........
Water recirculates to disapate the heat from combustion.....fairly new radiator, fan clutch, radiator cap, water pump, and thermostat.........there has to be some sort of restriction or bad pump to cause it to shoot up suddenly like that. I'm guessing a bad thermostat (they are made by man!!). Just a thought and a pretty cheap test. Good luck!

 

[joejeepny]

OK...not a mechanic here, just trying to think logically.........
Water recirculates to disapate the heat from combustion.....fairly new radiator, fan clutch, radiator cap, water pump, and thermostat.........there has to be some sort of restriction or bad pump to cause it to shoot up suddenly like that. I'm guessing a bad thermostat (they are made by man!!). Just a thought and a pretty cheap test. Good luck!

Or the temperature sending unit or gauge is intermittently shorting out due to the extra heat from the summer. The radiator will normally burp into the overflow as the temperature increases and suck it back when it cools, thats why the tank is their and the cap has a pressure release. If it didnt do that the radiator or hose would explode during normal use in the summer months. Air pockets in the system expand under heat. Liquid does not. So make sure everything is filled correctly on level ground. If there is air in the system and the truck is on an angle the air wont burp fluid will.

 

[mud4feet]

Or the temperature sending unit or gauge is intermittently shorting out.............

Well, yes, I did forget about that. Stinkin' electronics. Not sure how to check the actual temperature, other than the smells they emit.......something else to check - the gauge.

 

[Boffman98Jeep]

Have to keep head gasket in mind also. Seen many go in my 15 years of automotive experience.

 

[Saddle Tramp]

I have to 2nd the head gasket possibility. This is from the "been there done that" file.

 

[fubar62172]

3rd for head gasket. This is coming from one who's in the process of putting one back together

 

[cuba_pete]

My 98 wrangler started running 210 -220 then seemed to shoot to red in seconds! We have replaced thermostat (fail safe 195), fan clutch, radiator cap (18 ) and within the last year waterpump and new radiator. Do I have the right size thermostat and cap? We have "burped" radiator. What else could it be??

Watch your hoses when it's hot...they are probably collapsing. Classic for your symptoms.