This is not a wrenchin secret, just thought someone may know the secret of getting some heat out of my driver 03 Century. It's cold here in Ohio. I have had this car since new and up until last year the heater/defroster worked great. I have changed the stat three times in the last year(used parts from my GM dealer, 195 degree) still very little heat. The stats are opening as after it runs about 7-8 min. the heat gauge goes up and then down to normal when it opens. I have also changed the antifreeze(with the pink stuff) and flushed the system. I can't find any vacume hoses bad and I don't know what to look for as far as a heater valve or something like it. Can anyone give me a clue as what I should try next?
Not sure of your Century, but the climate control doors on a lot of GM cars are controlled by actuators, small boxes with little electric motors that move the doors. Sometimes, the gear drives get stuck, or break, and the door they control is stuck in one position. They can be taken apart and repaired in a lot of cases, and I believe Dorman makes replacements. My 98 Riviera uses about 5 of them I think. Here is a page from the site I go to when I need information about my 98. This site is to the 95-99 Rivieras, like V8 is to our cars. http://rivperformance.editboard.com/t2500-write-up-hvac-assembly#27279
My mother's 05 3100 century had the same problem, the heater/defrost wouldn't get hot. It turned out to be a clogged heater core.It took just a few minutes to unhook the lines going to the heater core and flush it out with a water hose. In case your not sure where the heater core lines come out. Look on the firewall about middle of the car, and it's the rubber lines right below the metal ac lines. They have an attachment point at the firewall and also another one, real close to the top backside of the motor,which is what I had used..
the thermostat on my truck stuck open, it would never warm up and the heater blew cold air but it was easy to identify as the check engine light would come on after a while. If you have a code reader you might want to check that out.
I JUST went through this with my zr2. I replaced the t stat and flushed the heater core. One line was hot and the other cold. I unhooked both from the intake and shot water in the cold hose forcing a bunch of red globs of Crap out. I then alternated several times between hoses to make sure it was clean. Nice and hot now! Good luck,
the problem could also be the climate control head. had one of those replaced on my '98 regal gs, under warranty.
X2. my 2000 chevy 2500 6.0 had the same problem 2 years ago. I flushed it at the heater core hoses . I also got the red globs from the GM orange anti freeze. After the flushing and refill with new anti freeze I was getting 160 degrees out of my vents. Dealership told me that on some vehicles there is a screen on the inlet to the heater core and the globs don't pass thru.
