Engine Overheating

[Tweakin'Sport]

I have a 2000 Sport 6 cyl that is overheating. I thought that it may be the thermostat but the hose coming from the top of the thermostat gets hot so I believe that means the thermo is fine. Also, the truck overheats on the highway just as quickly as when I drive in the city so I am assuming that the fan is still running well. If the thermo and fan are fine, what could possibly cause the overheating? Am I incorrect to assume the thermo and/or fan is fine based upon the above facts? Thanks in advance for any replies.

Mike

 

[Creatve]

is your coolant low? any signs of leaks?

 

[Tweakin'Sport]

As far as I can tell there are no coolant leaks and my overflow has coolant at the apporpriate level so I am assuming that there is enough coolant in the system. The coolant has a brownish tint in the overflow so could a radiator flush possibly solve the problem?

 

[Creatve]

well i would check to see if theres coolant in the radiator at the radiator cap just to be sure. if the engine is hot, wait till it cools down a bit before opening the radiator cap or put some cloth over the cap and slowly turn it open until you hear it releasing pressure and coolant may spew out. stop turning let it finish releasing pressure then take it off.

also take note how the radiator looks inside, hopefully it isnt too bad since u said you saw some brown stuff in your coolant

 

[Tweakin'Sport]

I opened the radiator cap and the coolant was at the top and the engine was cold at the time. Also, the fluid looked clean and green from what I could tell, a lot different from the fluid in the overflow. Since there is no leak, perhaps I need a new radiator?

 

[Creatve]

well if your radiator isnt leaking and its not rusted inside, your radiator is perfectly fine so i wouldnt replace that. something else is the problem. is the top radiator hose getting hot before your vehicle is overheating?

 

[Tweakin'Sport]

Yes, the top radiator hose does get hot before it overheats. I think that means the thermostat is opening fine.

 

[shamaal]

Quick check.

Squeeze the hose when cool. Squeeze when hot, it should
be noticeably stiffer. That's the thermostat opening and water flowing.

Be careful around moving parts

 

[nolimitssjca]

Pull the thermostat out and run it without for a short time. If it overheats you may have a waterpump prolem. If it doesn't over heat then you may have a faulty thermostat.