Overheating, blown radiator, other issues?

[ProjectTrinity]

I have also had an issue similar too with my supercharged 3.4. The previous owner said the headgaskets went out and the truck overheated so he had the headgaskets replaced along with the timing belt, water pump, and radiator. The truck still was overheating so he swapped out the radiator for a champion radiator and drilled out the t-stat.

In this setup he said it doesn't overheat. Since I have had it, city driving is fine and the temps stay super low but at highway speeds going uphill, the gauge will read 3/4's almost to red. It was strange to me because the scanguage reads 190 when the temp gauge is at 3/4.

I am hoping it's a faulty water temp sender for the temp gauge and I can just install a 170 degree thermostat. What would cause the temps to rise at highway speeds with a new radiator and fluids?

 

[ED2001T4R]

Thank you all, guys. I am leaning toward a water pump issue, because it has been about 16 years since it was installed!
Just curious, and forgive my ignorance, but with the truck having been examined by two separate dealers, wouldn't a water pump issue be readily obvious, or does it need to be dismantled to see if it has failed?
Being a bit cynical, I am surprised two separate dealers didn't try to sell me an expensive water pump job, after all. I may have mistakenly told them the water pump was relatively new (which I thought at the time - long story!).

 

[gamefreakgc]

I have also had an issue similar too with my supercharged 3.4. The previous owner said the headgaskets went out and the truck overheated so he had the headgaskets replaced along with the timing belt, water pump, and radiator. The truck still was overheating so he swapped out the radiator for a champion radiator and drilled out the t-stat.

In this setup he said it doesn't overheat. Since I have had it, city driving is fine and the temps stay super low but at highway speeds going uphill, the gauge will read 3/4's almost to red. It was strange to me because the scanguage reads 190 when the temp gauge is at 3/4.

I am hoping it's a faulty water temp sender for the temp gauge and I can just install a 170 degree thermostat. What would cause the temps to rise at highway speeds with a new radiator and fluids?

Yeah, you're on to something there. Either the Engine Coolant Temperature Sender unit is bad, or the Engine Coolant Temperature Sensor is bad. If it's the sensor that's bad your engine is going to overheat again. If it's the sender, it's completely harmless and the dash gauge will be off. Replace the sender but if it still does it I would change out the ECT sensor next just to be safe.

 

[ProjectTrinity]

Yeah, you're on to something there. Either the Engine Coolant Temperature Sender unit is bad, or the Engine Coolant Temperature Sensor is bad. If it's the sensor that's bad your engine is going to overheat again. If it's the sender, it's completely harmless and the dash gauge will be off. Replace the sender but if it still does it I would change out the ECT sensor next just to be safe.

Late response but mine ended up being the headgaskets being flipped. So the right HG was on the left side and left HG on right side, blocking a coolant port. Was an expensive fix but still less than a new engine at least. The shop who did the first job must have been blind. So now everything works fine and the engine stays 180-190 for the most part.

 

[gamefreakgc]

Late response but mine ended up being the headgaskets being flipped. So the right HG was on the left side and left HG on right side, blocking a coolant port. Was an expensive fix but still less than a new engine at least. The shop who did the first job must have been blind. So now everything works fine and the engine stays 180-190 for the most part.

Wow, good catch! The accidental switch usually ends in a blown engine.

 

[ProjectTrinity]

Wow, good catch! The accidental switch usually ends in a blown engine.

I was really hoping it wasn't that lol. I also had a cracked head so had to get that fixed as well.

 

[devbo]

I need to know what ended up happening with your car, OP?

 

[desertegal7]

if your temp is ok but you feel the engine is hotter than its supposed to be then replace the oil pump as well