Cooling System Background:
I had the dealer flush the dexcool about 5000 miles ago. The dealer said there was some funky stuff in the radiator, and that I had made a good call getting it flushed. Sometimes I hear gurgling from the heater core. No wet passenger floor surprises so far, and the heat still works.
The Symptoms:
Driving through low-speed or no speed, city traffic, the water temperature quickly gets into the 230-235 degree range. When I get to highway speeds, the vehicle instantly goes back to normal operating temperature of about 190 degrees.
In my past S10 Blazers, an 86, and a 93, when things got hot, the fan clutch would firm up and you'd hear the familiar loud fan whooshing sound.
Not-so-scientific testing:
My roommate has a 97 blazer. I got both vehicles up to operating temperature... and mine beyond that to 230 degrees driving around the block a few times. His fan has a bit more resistance than than mine does when trying to turn the fan.
I'm fairly convinced the fan clutch is most likely the problem. What other elements in the cooling system could cause a consistent behavior like this?
Regards,
Lane Jennison