Engine Temp running cool

[03olblue]

My truck is doing the same thing, had a thermostat keeping the truck around 185-190 and flushed coolant and changed thermostat because I thought it may be stuck open but still running at 185-190. 2001 Silverado with 4.8 and 5 speed manual. Any advice? Would like to keep it at 210 to ensure good gas mileage/parts wear

Edited October 8, 2019 by 03olblue

[rjgti]

fan clutch always on

[CamGTP]

20 hours ago, 03olblue said:

My truck is doing the same thing, had a thermostat keeping the truck around 185-190 and flushed coolant and changed thermostat because I thought it may be stuck open but still running at 185-190. 2001 Silverado with 4.8 and 5 speed manual. Any advice? Would like to keep it at 210 to ensure good gas mileage/parts wear

 

What your truck is doing is completely normal though.  A new stock thermostat is suppose to keep the running temp at 185-195. Don't forget that the cluster reading does not always match the real coolant temp that a scan tool would show.

 

The engine is designed around that temp, so there won't be any extra wear on parts. You'd have to block off a ton of airflow to the radiator if you wanted it to run at 210 all the time, plus your clutch fan would be running all the time reducing your mpg.

[dkjbama]

22 hours ago, rjgti said:

fan clutch always on

This... possibly. The viscous coupling in an engine driven fan typically fails in the locked up position. With the truck in park and warmed up, rev the engine and listen for a howling noise from the fan.

[melletj]

I have a 2004 Sierra 2500 HD with the 6.0L and I have replaced the viscous fan clutch, thermostat (with factory ~187F), and the coolant temperature sensor on the driver side cylinder head toward the front and everything stays the same on the gauge.  I have read the temp on my BlueDriver (highly recommend, by the way) and it reads about 195-198F.  I'm thinking this sounds about right, but wondering why the gauge in this truck doesn't run in the ~205F range like the others I have had.  It currently sits around the 180-185F mark.  I'm wondering if this could be related to the stepper motor in the instrument cluster because it sounds like GM has had a lot of issues with them.

 

Thanks,

Tom

[txab]

Could be stepper motor, but also could be that the motor has been replaced by this point in your truck's history. If so, it's probably they didn't get the needle set in the proper position after rebuild

[melletj]

I thought about this.  When I got the truck at ~267,000 miles, most of the cluster lights and other switch lights in the truck were burnt out.  I did take the cluster and the HVAC controls (standard, not auto) out and replaced all of the bulbs.  I tried to put the needles back where they were, but you're right, I don't have any idea if someone else had been into mine.  It sounds like there are some that it changed without any work to the cluster, though.  I was thinking that I could just adjust the needle to make it go where I want it to!  I guess that may not be the most accurate, but I don't think the gauges are always that accurate anyway.

[Sharpz]

58 minutes ago, melletj said:

I thought about this.  When I got the truck at ~267,000 miles, most of the cluster lights and other switch lights in the truck were burnt out.  I did take the cluster and the HVAC controls (standard, not auto) out and replaced all of the bulbs.  I tried to put the needles back where they were, but you're right, I don't have any idea if someone else had been into mine.  It sounds like there are some that it changed without any work to the cluster, though.  I was thinking that I could just adjust the needle to make it go where I want it to!  I guess that may not be the most accurate, but I don't think the gauges are always that accurate anyway.

as others have said, dont go putting too much faith into that cluster gauge.