I have replaced my factory thermostat with a 186 degree Thermostat. My temperature gauge still reads just shy of 210. Do you think it would make a difference to change to a 180? Would it be too cold for winter? Vancouver,B.C. 0-5 degrees. Opinions???

 

Do you have a programmer for your vehicle, if so did you re-tune the fans to come on sooner?

 

2004 has a mechanical fan clutch so there is no way to reprogram them to come on sooner.
The thermostat sets the min operating temp not the maximum temp. I would bet you have a plugged or partially plugged radiator. You can try and flush it to see if that will help. Your truck should have a 195 degree thermostat. A 180 degree stat will still provide plenty of heat for winter.

 

Thanks to all for the advice. I switched to electric fans and supposedly had my predator to set the temp at 186 on a custom tune. Still reading shy of 210. There was another thread somewhere about a plugged return nipple to the expansion tank or something like that. Going to take your advice and reverse flush my rad and new coolant.

 

DUH I should have read your sig. and seen you had Electric fans.

 

purchased the 03 and noticed just shy of 210deg. changed to a 180 with a full system drain. all fluid looked great. no leakes anywhere. refilled system and still @ 209deg. any ideas please?

 

maybe your putting in the wrong type of radiator fluid? orange vs. green

 

210 is right in the middle or the gauge no? Isn't that about perfect?? If its just shy of the 210 mark I don't understand what the big deal is especially if there are no overheating issues. A few degrees before the mark on the gauge isn't going to change anything-it could even be the temp sensor.

 

Those gm temp gauges are basically enhanced idiot lights. I havn't personally had an accurate temp gauge in a GM vehicle since 1998, but I dont have anything newer than 2004. The ECM does read an accurate temp. I just plug in my scan tool if I want to check out whats really going on.

 

Hi to all.

Verify your cluster readings (stepper motors).

My H2 was reading 210C even higher with 197C thermostat. After a new set of stepper motors installed, engine the temp reading was exactly 197C. The trans temp was reading 150 and 160C (obviously with a bigger oil cooler), and now read 140-150C.

Just my 2 cents.