2002 Trailblazer Runs Hot

[MA Trailblazer]

I just picked up a new 2002 Trailblazer a few months ago, and noticed it seems to run very hot. The gauge on the dash will run dead up at 210 once it warms up, even if it is a cool day. ( 50 outside )

 

 

As today is one of the first hot days in my area, I noticed the temp gauage runs 2 lines ABOVE the 210 mark. When I hooked up my autotap to see if the gauge is correct, it shows the engine coolant temp at 217 when I am at idle with the A/C on. ( outside temp is 85 ) Once I get on the highway, autotap shows the temp will drop to 210. I thought I read that these motors have a very good cooling system, and a 190 thermostat, so I didn't expect it to run this hot.

 

Is this a normal temp for these motors?

 

I just read a write up on the long term TB that Autoweek has in its fleet. They mention that the dealer had to reprogrammed a faulty cooling fan clutch. We do not have a electric cooling fan, so how do they reprogram it?

 

You can read the whole article a www.autoweek.com

 

My old 2001 blazer would only run near the 210 area on a VERY hot day, sitting in traffic, with the A/C on, and NEVER went above the 210 mark.

 

John

[CMNTMXR81]

Yes, that's normal.  GM runs them hot for emissions purposes although admittedly I'd say that's on the high side.  You can figure anywhere from 190 on the low side up to 210-215 on the high side is the acceptable range for a stock thermostat engine.  The hotter it runs (just this side of boil over of course), the more hydrocarbons it burns, therefore running cleaner.

 

Another thing to keep in mind, the factory gauges aren't exactly the most accurate in the world due to calibration.  The best way would be to scan the PCM to see what it's picking up vs. what the gauge is reading.  I've seen variances of up to 10 degrees on my vehicles alone.