96 SLT 5.9 Mag


I have replaced the thermostat, flushed the radiator, viscous fan, and it has a new water pump as well.

During the winter, I could not get it anywhere near the 195 that it is required to make. I actually drained quite a bit of coolant off to at least make it half way up to 200. I can gas it hard, and really build heat to 200, but when I drive normally, it cools off. I did test the thermostat to make sure it opens gradually as it makes 195 in a pot. I am missing the dirt flaps on the left and right of the condensor and radiator, is this enough ram air to keep it from getting to temp?

I am afraid that my engine is building carbon, as well, the cat is going to get plugged

 

Think I would be inclined to plug in with a scanner, and see what temp the PCM thinks the engine is getting up to. On yours, there are two sensors, one for the PCM, and one for the gauge. My bet is, the gauge is lying to you.

 

I'll scan it, but when I was running it in winter, and it was barely making the 130 mark, i was getting no heat from the heater core for the cab. I also, stuck a thermometer in the radiator, in March, and was getting no heat in the radiator either. I think it was like 110.


But let me see about that scan

 

Coolant flows from right to left(standing in front) so you where measuring the cooled side. There have been others that have had the same issue and it was the t stat was not in tight and coolant was bypassing it.

 

I've only seen this 1 time. Twas on a '72 olds 350. Same problem, wasn't getting up to temp. The dude i was workin' for found out after much consternation n trips to the parts cannon that the block was clogged up in the water jackets. Only part of the block were being cooled n not enough heat was being transferred by the coolant that was still circulating. Try draining the block n then go for a full flush until the water blows out clear n refill with water n try again.