Overheating issue...

[CountyLineGarage]

Did you figure it out, my 95 just started doing the same thing.

Have you done anything to it coolant wise recently?

 

[1997]

nope,
working good one day, next same symptom as you, pegs guage when cold in about 5 min's, thermostat opens, cools down, repeat 2 or 3 times, then runs about normal operating temp.
verified temp guage is correct and changed thermostat, stock 195 degree.

 

[CountyLineGarage]

nope,
working good one day, next same symptom as you, pegs guage when cold in about 5 min's, thermostat opens, cools down, repeat 2 or 3 times, then runs about normal operating temp.
verified temp guage is correct and changed thermostat, stock 195 degree.

Honestly, I’m not 100% sure what was causing my issue. I ended up needing head gaskets and a bunch of other stuff and it ended up fixing it for a while. Now it will get up to temp and drop down after driving for a short time. Not sure if it’s just the way these gauges read or what.

 

[L31MaxExpress]

Honestly, I’m not 100% sure what was causing my issue. I ended up needing head gaskets and a bunch of other stuff and it ended up fixing it for a while. Now it will get up to temp and drop down after driving for a short time. Not sure if it’s just the way these gauges read or what.

My van has always shown halfway between fhe large 1/4 hash and 210 on the gauge briefly before the thermostat opens, then settles down at the 1/4 mark. 170°F thermostat and generally it runs 176-182°F at the PCM verified by IR on the thermostat housing. With a stock 195°F I could see that spike being 210°F before it opens.

 

[Jeepwalker]

Your problem might have been a bad headgasket from the beginning. That can cause overheating ...and overpressurization of the cooling system. Have you been hearing a 'gurgling' noise in your heater core at all before you did the HG?

Also, its real important to get a 'good' thermostat. The quality of mainstream low-buck T-stats has gone down. That's not one part to cheapen out on.

Glad you got your rig back on the road.