2003 Yukon - slow to warm up

[sagent]

My 2003 Yukon seems to take forever to warm up. I let the truck idle for 15 minutes at about 10 degrees farenheit and when I get in the temp needle has barely moved. My 2011 2500HD warms much more quickly and that is not parked in a garage. Have not been driving the yukon as much as we used to as I bought my wife a Corolla so maybe I forgot the long warmup ? I understand there is a lot more volume to heat in the Yukon vs the 3/4 ton but still I am watching the temp gauge vs how it feels in the Yukon. Once you start driving it & engine finally reaches full operating temp it throws out plenty of heat

 

Last winter had the cooling system flushed / refilled and put in new thermostat. Did not seem to change anything

 

Any ideas as to what to check next ? Would it make any difference if one vehicle is aluminum head / block vs cast iron block ?

[waumo1]

Since you are watching the temperature gauge, it seems the thermostat would be the only likely issue. We had a 2002 5.3L Yukon and it also seemed to take a long time to heat up at idle but as soon as you started driving, it came right up to temp.

[yukon25008.1]

I was thinking maybe the stat was stuck open and not letting the engine come to temp,

[Black2011]

My 2003 Yukon seems to take forever to warm up. I let the truck idle for 15 minutes at about 10 degrees farenheit and when I get in the temp needle has barely moved. My 2011 2500HD warms much more quickly and that is not parked in a garage. Have not been driving the yukon as much as we used to as I bought my wife a Corolla so maybe I forgot the long warmup ? I understand there is a lot more volume to heat in the Yukon vs the 3/4 ton but still I am watching the temp gauge vs how it feels in the Yukon. Once you start driving it & engine finally reaches full operating temp it throws out plenty of heat

 

Last winter had the cooling system flushed / refilled and put in new thermostat. Did not seem to change anything

 

Any ideas as to what to check next ? Would it make any difference if one vehicle is aluminum head / block vs cast iron block ?

 

 

unless It has recently changed drastically, I would not consider it a problem. consider a block heater as well as a winterfront. (piece of cardboard in front of the rad)

 

you could try a thermostat, they are relatively cheap and simple to change in most applications. (not sure about yours)

[Big Whiskey]

I was thinking maybe the stat was stuck open and not letting the engine come to temp,

 

 

I'm thinking the same thing. I'd try a new thermostat.

[Gone Again]

All thermostats are not created equal. Get an OE to be on the safe side.