running hot

[1Bad4558]

I have a 95 gmc truck that is running hot and I can't figure it out. I've replaced all hoses radiator thermostat and fan clutch. It only runs hot going down the highway at interstate speed. The only thing I can think of is that there is a blockage in the motor somewhere. I've already flushed the system but it still doing it. I know this doesnt involve a g body car but any insight on what it could be would be helpful.

 

[wonderboy24]

does it take awhile to get hot? my son had the same prob with his truck,we did the same thing replaced radiator thermostat and all hoses cluck fan and still did it,it ended up being his catalytic converters were plugged. we cut the exhaust and found they were plugged.

 

[1Bad4558]

I have no converters on the truck. When I ran exhaust a few years ago I dome away with them.

 

[1Bad4558]

I have no converters on the truck. When I ran exhaust a few years ago I dome away with them.

 

[wonderboy24]

you said you flushed the system? hows your belts?

 

[seawolf18]

Water pump? Get all the air out of the system? Is the gauge giving you an accurate reading?

 

[LS1GN]

Do you know for sure it is overheating? gauge could be bad
stuck caliper?
timing?

 

[1Bad4558]

The belts are good and yes I flushed the system. I made sure all the air was out when I refilled with coolant.

 

[1Bad4558]

I also replaced the water pump. Forgot to mention that in the first post. I hooked up a mechanical guage to check and make sure it was reading right and it was doing same thing.

 

[chevy2480]

Get it hot and see if rad feel consistant as across it and up and down. If big difference is felt radiator is clogged. Regardless if flushed could still be plugged up. Been there done that.