Engine Temp and Heat

[lgret13]

I have an 03 rendezvous and live in New York and today its pretty cold out, (understatement) I notice today that the heat in the car was not getting as warm/hot as usual, I warmed up the car for at least 20 minutes and did some moderate highway driving, and after 40 minutes the car was warm/cool but not hot and I had the climate control on 80degrees the entire time. Also, I noticed that the engine temp gauge usually reads at the mid mark (no numbers on the gauge) but the entire time even after driving the gauge remained at the quarter mark. Could this be affecting my heat and also, is this normal for the engine temp to stay at this level in cold weather. It seems it never got up to full operating temp. (I don’t know if this makes a difference I have the upgraded radiator from the trailer towing package)

Thanks for the responses in advance.

(With the AWD Buick no reason to chance anything happening to the 300C )

[Vanilla]

dude, get a new engine thermostat...bad for your engine to run below the normal temp...and probably bad for gas mileage since the computer will run it richer....

btw, you can have a radiator the size of a house in your car, but if the thermostat is working properly, the engine will be at the right temp.

[II kings 9:20]

ditto, new Tstat, stat.

[lgret13]

thanks, i have to bring it in to the dealer at least it should be covered under warranty, and only have 15k miles on the truck too.

[Vanilla]

if you or a 3rd party did the radiator upgrade, prepare for b.s. from the dealer about not being able to warranty the cooling system since someone else messed with it...if it was part of a factory or dealer installed upgrade, then you don't have anything to worry about.

[lgret13]

the radiator was factory installed, i heard from another buick owner that the coolant might be leaking into this particular engine setup and the head gasket may need to be replaced, sure enough i check the coolant level and it is slightly low (never crossed my mind to actually check the coolant level because always thought if it was low the engine would over heat). i also notice that the heat blew stronger and hotter at higher rpm and the temp gauge increased slightly, seems like there may be a multitude of problems including possible the thermostat. i have a dealer appointment tomorrow, unfortunately unlike the 300c warranty no loaner car (when i had the radiator recall done and pcm flash they gave me a 2004 Grand Cherokee, can't complain about that). we'll see what they find. thanks.