This 08 Buick with dual climate controls has very little to no heat. In Florida we really dont worry about heat but with this recent cold snap its nice to have warm feet while driving. I transfered the tags and ins off the 97 Riv onto this car so I could put some miles on it and work out the bugs before I pass it onto its next owner. When I first started messing with her she had limited heat on the drivers side and nothing but cold on the passenger. Its a dual zone system so that would tell me its a blend door. The temp selector goes to 90 and it blows luke warm but when I drop it back to 80 and select recirc it gets warmer until the selected temp is pushed back up to 90. (Maybe a blend door, god I hope not) I've flushed the radiator and replaced the thermostat and if anything its colder than before. Heater hoses seem to be at least engine temp in and out so pretty sure its got good flow. Next week when its warms up a bit I plan on doing valve cover gaskets. The rear one is leaking and the fresh air intake is right above the leak so it smells like burning oil in the cabin. On this car the engineers thought it would be cool( no pun) to route the coolant through the alt / tensioner bracket with 2 plastic elbows. That has to be removed to get the valve cover off so while Im in there will flush the heater core. Will replace the elbows with the new aluminum connectors. Im hoping thats fixes the issue. If it turns out to be under the dash I'll probably take it into a dealer and just bite the bullet / pay the price . Hate working under the dash of our old cars but thats a walk in the park compared to these new vehicles.
You will need to use a scanner to read coolant temperature and see commanded and actual position of mode/blend doors. The actuators for the doors seem to be an issue with a lot of vehicles. Some are easy to replace, some are not, but either way, you need a scanner. When you get the valve covers off, check for cracks. It's a common problem if they are plastic.
My 2003 Suburban needed the blend door motor on the passenger side . No warmth at all but if I pulled over and shut the vehicle off and restarted the problem would fix itself . Dealer quoted anywhere from 5 to 8 hours . Shop manual said to remove the front bucket seats and center console to get the dash out of the way to replace . I didn't do either . I got the dash out enough to replace it in 1 and 1/2 hours as it was my first one . I told my Service Writer friend at the dealer to line up 4 jobs a day and I would do them for 4 hours each .
John is right too Briz . My 2000 Silverado 2500 requires a back flush every couple of years but this is because there is NO HEAT at all . Briz is the heat the same for right and left ?? Or is the heat good on the drivers side and lousy on the Passenger side ?
My 04 yukon is doing same thing but backwards......my passengers side gets stuck on full heat every morning......so I have to turn the temp to 60, turn off the climate control, restart engine, then I have full adjustment........I can't picture an actuator only not working 1st thing.... I think its my control unit Brin a couple of easy way to help check between heater core and temp actuators..... Turn to full heat let car get to temp.........listen and feel for air flow difference when switching from hot to cold......the air volume seems to always pick up when going to full cold.....this will help you to know the actuators are moving. Another is set it back to full heating car at temp. Turn fan off for a few minutes.... .then turn it back on....if you get a puff of heat for like 45 seconds.....then it goes cold its likely a plugged heater core
My 05 chevy truck used to go full cold on the driver side when I bought it back in 08. I always laughed at the dual climate in a single cab truck.. anyway, I believe I picked one connector under the dash and it solved my problem.
It had decent heat on the drivers side only until I flushed the cooling system and replaced the stat. After that the temp gage stayed steady on the center mark but only marginable heat on the drivers side. Seemed to get a bit warmer as the temp control was lowered n raised but never hot. Passenger side always cold. Weather is supposed to warm up into the 70's by the end of the week and will do the core flush then.
If its worse I wonder if it's air bound. Is there a bleeder somewhere? That used to be a thing when I was wrenching..
there is a way to recalibrate those actuators, pretty common, but I can not remember the procedure, may have to check utube.
Most of them, at least the older ones just require cycling them from full hot to full cold after they are installed. Do not, as a check, just plug in a new actuator and move the temperature control from hot to cold to see if it moves. If you do that, that's all the actuator will move when installed. After the actuator is installed, move the temp control to hot and leave it in full hot for about one minute and then move it to full cold for about a minute before turning the system off. It doesn't take a full minute to get to full hot or full cold, but without a scan tool to show position, you need to make sure that it moves the door fully one direction before switching direction and making sure that it goes fully the opposite direction. If you move the temperature control the opposite direction before the full travel is learned, that will be the new learned position.
Yes, that's it! you can even do it to the original actuators and many times they will start working. The key is waiting the right amount of time between cycling. Thanks, 1973gs!
Friday afternoon it got up into the 70's. After work I had about an hour of daylight left so jumped into the project. Watched a couple of vids over the week so I knew where to start and what to look for. Before the light gave out I managed to get it down to where I could pull the valve covers. Flushed water through the core into a clean bucket and some crap did come out ,but not enough in my opinion, to clog it up. Funneled a bottle of CLR into it and let sit overnight. Had planned on finishing the job Sat morning then the scammer investigation change my plans. Got home around 2 then finished.More stuff came out of the core on the final flush. Ran the water until it was clean coming out both directions. While there replaced the complete tensioner assembly along with the elbows. Wasn't too bad of a job. Filled the system with coolant burped out all the air and BINGO! the heat works. Also it seems that the passenger side is working as well. Will drive it around today and see what happens. Next project is to pull the int and do a complete detail. Should be ready to sell after that.
My stupid little Corolla XRS had a problem with no heat on One side out of vents and here I find out it has 2 sections to the heater core. I had a place do the pulse flush and it worked for about a month and had to go back and have it done again and now all good. My buddy had a Buick LaSabre from about the same era and he was having a lot of trouble getting no heat also he never did get it figured out and now I wonder if it was just the heater core plugged up.
