overheating while at a red light help please

[nissan1995]

when i drive my truck not even very far like a 15 min drive then stop at a stop light for 2 min my temp gauge goes up just under the HOT tick mark, but when i start to drive it goes back down to under halfway.

any questions to what it is?

[VG30E]

Water pump
fan clutch
thermostat

Is it boiling over?
You got any coolant coming out?

[nissan1995]

no it does not boil over or leak coolant

KA24E
forgot to add that

[VG30E]

My first guess is fan clutch/tstat.

Could be the coolant temp sensor though.

[nissan1995]

how could i test the (fan clutch, tstat, and coolent temp sensor) to narrow it down to one problem?

[alabama_lowlife]

well, the thermostat is like $5-10 and a water pump from the parts house is like $40. if you have an accurate thermometer you can put the thermostat in water on the stove and see at what temperature it opens. you could also see if it is opening, but only partially or something like that. a household thermometer probably doesn't go high enough for this...i haven't checked, but i doubt they do.

[JsD21HB]

could be posibly low coolant or a possible air bubble too. and household cooking thermometer should go to boilng i think our stats open at 189ish.

[SkinnyG]

You should hear the fan drawing air if the fan clutch engages. Fan clutches often fail in the stuck on position.

If the thermostat opens, you should see coolant flow in the rad with the cap off when the thermostat opens, then shut off. Thermostats often fail in the stuck open position.

Temperature sender can be checked with an ohmmeter.

Does the engine "feel" piping hot when the gauge is pegged? (feel the top rad hose).

G

[IThaJokaI]

To check your fan, spin it while the truck is off. It should have minimal rotation ability.

Mine went bad in my HB also, guy said they go out often on SOHC engines.

[nissan1995]

my fan work as u said has minimal rotation ability

i fixed the probled my heater hoses were pinched a little to i fixed it and thinking that worked