EOT & ECT high temp

[Tmoney511]

The other day I noticed that my truck was taking longer to reach temp from my CTS. The EOT and ECT would climb at a slow rate but would only stay 3-5 difference from each other. I didn't really think nothing of it tell I was at a stop light and looked at my CTS and noticed my EOT & ECT temps were both at 230 degrees.... Could this be the cause of a bad sensor, bad thermostat, bad water pump, or is my oil cooler just super clogged?

[rentstdi]

If you have a way to check you temperature of your radiator, check the temps on the top tank and bottom tank. Or radiator hoses. They should have 20-30 degree difference. I normally use a inferred tempurature gun for this.

If this has gradually happened I would look into the water pump for more info

If you have tried to flush your coolant system most likely you radiator is clogged but you oil cooler should be clogged also unless you already replaced it.

[Snake]

I'm leaning towards the cooling / coolant side of things. Even when my oil cooler was clogged and my EOT's were 240* or more, my ECT never went above 210*. Check your thermostat first, then the fan clutch, then the water pump.

[Tmoney511]

I flushed the whole system and even did a reverse flush of the oil cooler in June before putting a new oil cooler in it. I run CAT EC-1 coolant. Somedays I'll get a fan clutch DTC and other days I won't. Thermostat and water pump have never been replaced. I noticed the issues I stated earlier the day after my truck was completly covered in mud and my engine was black. I had to do a rescue mission on a friend who barried his GMC on 2.5 tons.

[dannyboy950]

Originally Posted by Tmoney511

I flushed the whole system and even did a reverse flush of the oil cooler in June before putting a new oil cooler in it. I run CAT EC-1 coolant. Somedays I'll get a fan clutch DTC and other days I won't. Thermostat and water pump have never been replaced. I noticed the issues I stated earlier the day after my truck was completly covered in mud and my engine was black. I had to do a rescue mission on a friend who barried his GMC on 2.5 tons.

Under that condition I would see about washing the mud out of my radiator, cac and a/c condensor

[Snake]

With 180k miles on the truck, it's very likely that your thermostat, fan clutch, and/or water pump are due for some troubleshooting (and possibly replacement).

Is there any relationship between the fan clutch DTC's and when your coolant temp spikes?

[ZMANN]

Somedays I'll get a fan clutch DTC and other days I won't.

this ,,,,,,,,,,,,,,,,,

[Tmoney511]

I washed it all for hours. I saw a little more mud in the fins of the radiator so tomorrow I'll clean again. Each time I get that DTC I have high coolant temps. I'll drive the truck and reset the DTC's and get the fan clutch DTC right away. Any of you know how to replace the fan clutch? I'll be checking the thermostat tomorrow and possible water pump.

[Int.Tech04]

easiest would probably be pulling the shroud and fan as one. most guys unbolt the fan, set it against the radiator, and then remove the clutch. reverse process for install.

just be VERY careful. the radiators are so easy to pop a hole in its rediculous. i barely tapped one with a fan clutch on a international 4300 here at work, and bam, instant pinhole. about an hour job turned into a day long radiator removal and repair. the clutch is reverse threaded i believe. i know the one was on that 4300.