87 runs hot.

[greenbeer]

I have an 87 Ranger 2.9L with about 70,000 original miles. Since about 50,000, the temp gauge always reads on the "O" of normal when at operating temp. It never gets any warmer than that. What could cause this?

 

[Jester1994]

The first obvious check would be the thermostat, could be bad, or open. When did you last change your fluid?

 

[greenbeer]

Oh ya, forgot to mention. New: radiator, thermostat, water pump, and coolant. all new within the last year. That should help I hope.

 

[RockRanger]

maybe your sending unit is bad and is sending a hot signal to the guage. maybe try a new radiator cap if you didnt replace that as well. Is your fan shroud in good condition. Does the fan clutch work properly? Does it always run that high or just when idleing or on the highway?

 

[greenbeer]

New cap and fan clutch. It always runs at that temp. It seems to be the normal operating temp.

 

[RockRanger]

I am going to go with the guess of a funcky sending unit. Thats all i can think of.

 

[GTPETE]

yup or else just get an aftermarket gage

 

[410Fortune]

did this happen since all the new parts? or did you replace all the parts because of this issue?
Head gasket would be next, after you purge the system for air, possibly test the thermostat.

Does itheat up to the O and sit there right when you start driving the truck in the AM or does it still climb, go up and down?

 

[greenbeer]

Wow. This is an old thread. I fixed it a while ago, turned out to be a bad water pump (original). The blades on the the pump rusted away causing a low flow rate. Before this, I had never heard of that happening.