Truck is s10 01 with 4.3 when I shut the truck off the truck temperature gauge will creep up to as high as 2:40 but as soon as I start the vehicle it creeps back down to 198 I have a cheap send tech can OBD2 scanner twos and I check the freeze frames on it and it tells me that the coolant temperature is at the right spot 198 degrees but my temperature gauge says I'm overheating and it takes forever for my truck to cool down any recommendations already did the thermostat and flush the whole system

 

maybe a bad temp sensor or gauge?

 

The truck was overheating before I put a thermostat in it. It got so hot I had to wait three hours before I could put my hands on things and the old thermo was still hot to touch. Do you think the sensor is fouled from the heat?

 

Temp sensor data seems legit according to scanner I'm reviewing live data currently

 

Truck temp running stays between 198 -205 which is a shave above normal

 

It's residual heat, normal, the engin continues to heat after shut off because the water pump has stopped circulating the water and the water continue to assorbe heat from the engine remember it takes time for thing to cool down. When you start it back up water pump circulates the water through the radiator and the engin cools down. Now if the engine does not cool down after start up than you might have a problem .

 

My truck climbs to 250 in seven or so minutes is that normal?

 

When I stop to get gas and fill the tank when I restart the truck the temp has risen buy 2 or 3 line off of 210 as soon as I restart It begins to drop in the summer, like today , it's 95 degrees and I shut her off remained hot for along time in the winter when temps are in the low 30 high 20 she will cool down very fast. The thermostats controls the temp of the engine stock stat for 4.3l is 190 degrees don't be tempted to put in a cooler one as it will throw the computer off and gas mileage will suffer so will performance. A over heat only happens when the engine Is running. As long as the temp comes down after restart and stays down to normal you should be ok . Also the stock temp gauge in the s10 is not the best they can be off but they are a real gauge they react to variation in temp. Most cars today that have what looks like a temp gauge is just a fancy idiot light it will react only when the car is boiling over. The radiator cap in the 4.3l stock is a 15 lb. cap for every 1 lb increase in pressure you go 2 degrees higher in boiling point so you can go up to 240 degrees before the cap open to relieve the pressure . Make sure you don't have an after market cap as those go to 16 lb get a stock cap from gm. Make sure the cooling system she been burped properly ( got all the air out of the system) one way to tell squeeze the upper radiator hose it should be very frim when the engine is hot if it's soft could be air or a bad rad cap.

 

Thank you I'll UT new thermostat in I didn't know about this