Overheating
 

2002 Chevy S-10 Blazer 4x4 4.3L

I'm new to the forum and I have read many posts on here discussing overheating issues and I'm not finding the answer I'm looking for.

So here's what happened. My truck overheated two weeks ago. It got up to 250(between the 3/4 mark and 260 on temp gage). I cranked the cabin heat up and it stayed at 210 degrees all the way home. I immediately replaced the thermostat. It went back to normal running temp between 190 and 210. I took it for a trip to Texas from Oklahoma a week later and began to run the A/C. The temp rose to just before the 3/4 mark on the gage. It seemed to hover between a little over 210 to the 3/4 mark(Approx. 80 degrees outside). I don't remember it ever getting up that high before.

Today, I have changed the thermostat(again), fan clutch, and water pump just to cover all bases. It still hovers around 210 with no a/c. And it bounces between a little over 210 to just before the 3/4 mark on the gage with max a/c on.

I guess my question is "Is this too hot?". If so, what else should I do. I am at a loss.

(P.S: I noticed when I took the fan out there was a stamp on it that said "FRONT". This was facing the motor. Common sense tells me it should be turned around. When I installed the new fan clutch I turned it around so that the "FRONT" stamp was facing me. Was this the correct thing to do or did my logic fail me?)

That sounds a bit high. What kind of coolant are you running and what kind of condition is it in?

Your logic is correct with the orientation of the fan blade. "FRONT" must face the front of the vehicle, not the engine. If it's not installed correctly, it will create an air dam and restrict or prevent air from passing through the radiator.

Don't rely on the instrument panel temperature gauge. They are not known for their accuracy. Use an infra red thermometer at the thermostat housing, or use a scan tool.

Captain, how accurate is the temperature from the OBD? I run Torque on my android head unit and use that to monitor temperature among other things. Brucebonebrake you could use something like that to monitor the temp if you have a smart phone. All you need is a bluetooth OBD adapter and torque.

The ECT sensor reading on the scan tool is the most accurate way, provided it's calibrated correctly ;) Best way to know if it's accurate, is with a stone cold engine, (10 hours without starting it) key ON, engine OFF, compare Engine Coolant Temperature sensor, (ECT), Inlet Air Temperature sensor, (IAT), Transmission Fluid Temperature sensor, (TFT), and ambient temperature. They should all be within 2 or 3 degrees of each other. Another way is with an infra red thermometer directed at the ECT sensor. I like comparison better because you're checking temperature 4 different ways. If all 4 agree, chances are pretty good that's the correct temperature ;)