My bro's 94 3.0 is running hot according to the guage. It almost hits the red when idling, and drops a little on the highway. He has replaced the radiator, and the thermostat (twice). He has gone thru a qt. of oil in 1500 miles but the tailpipe is clean, so I'm not sure if that is the headgasket or not. Unfortunatley,the waterpump was not replaced when the radiator was done. Thoughts? Anyway to test a waterpump?

 

air in the system? could be water pump, but its not very likely. Water pumps generally work, or dont (ie rusted off fins, or the whole pump fails)

Take the thermostat completely out, and reinstall everything. Run the truck, and watch down the radiator to make sure you are getting flow. That will tell you if your pump is working or not. It will also tell you if its the thermostat, or if its air in the system (will bleed much faster with no thermostat). I know you have replaced the thermo twice, but sometimes you just never know.

 

squeze the upper radiator hose while the engine is running, if the motor id hot the hose will be too... put a rag over it. hold it for a couple seconds. once released, slowly, you should feel a surge of water come through the hose.

that test dosent cover the bearing/ seal ware tho..

ttyl

 

yeah try and bleed any air out of the system. i would also check and replace the radiator cap

 

are you losing any coolant? if your water pump is going out then it will leak out of the weep holes

 

I would guess that the problem is a bad fan clutch. A fan clutch pulls air at idle because there would not be any air flowing through the radiator when the vehicle is stopped.