Cadillac Deville 94 overheat on command center 4.9

[oilboy123]

Anybody know why the command center would show an overheat condition? Can the computer slow the car down in a overheat condition? I replaced the radiator and water pump, as well as the thermostat and serpentine belt/tensioner. The rad was bad and the pump was leaking at the gasket and when removed the bearing was rough. She was driving down the freeway and at one point was doing 17MPH and it was overheating. The radiator fan was working before.

I test drove it and it seemed OK before.

My Niece said that she read the engine was overheating and the car was slowing down. It also has a severe problem with hesitation and not being able to get out of it's own way. I assume that has nothing to do with it showing an overheat condition. After the overheat I checked for coolant on the ground and the rad and overflow bottle were full.

I am wondering if a temp sensor that feeds the command center is defective?

 

[The_Jeff]

Is this the northstar? They have a low/no coolant failsafe where it runs on fewer cylinders. I bet a water level sensor is funky.

 

[Chris142]

The 4.9L is not a Northstar. I don't believe that it has a way to detune it's self if it's overheating. I'd guess that it was on the verge of seizure and the low power was from detonation or vapor lock if it was that hot.

I may be wrong though.

 

[oilboy123]

Not a Northstar.

I should have made it clear that I replaced the radiator, thermostat, and water pump before this incident. It was full of coolant after I checked it for the supposed overheat. I am thinking the computer on the dash is giving a false overheat indication?

I idled it today and watched with a scan tool as the temps came up and the cooling fan kicked in every time.

I am thinking it never overheated but that a sensor was telling the computer it's overheating.