After about 10 - 15 minutes, my heater starts blowing cold. Is that a refrigerant issue? Or ???? Thanks for the help!
Thanks unclemiltie!First, if you still have codes 8 and 11 you still have blend door issues. you may have replaced the steppers but if the shafts are broken you are still in for some work to repair them. If the blend doors are in the wrong spot too much outside air is coming in and if it's cold out you'll get no heat. Take the motors off and do the recalibration (Off-Auto0 and make sure the arms are moving on the motors. Then check the blend doors themselves.
Second, did you recently change the coolant bypass valve? If you did there is a chance that you mixed up some of the hoses and this will get you no heat. (I did this once!)
third as Bob3000 said, whats the coolant level? what's the temp gauge doing?
lots of places to look but if you have the codes that's where you need to go first.
Great points you make. I think I have the original ACC unit. Now I have to find it! Thanks. I’ll get back to you.I happened to notice that in some past posts, (which I have also chimed in on regards the weird mid year 2004 change in stepper motors) that you have had some issues with the ACC. And that you might have swapped in a different ACC unit than was original to the car. I bring this up, only because the issues may lie there if the blend door issues can be ruled out.
It's maybe too wild of a guess to be constructive and may lead on a wild goose chase, but worth adding to the mix of places to explore for this issue, a faulty ACC unit?
This is not an apples to apples comparison, but i had the exact same symptoms on my 9000 last winter. 10-15 minutes of nice hot air, and then cool to cold for the rest of the ride. Long story short, swapping out ACC units was the eventual fix (after a few days of watching and testing everything else (internal temp sensor, stepper motor blend doors etc)
I dont know if there is a way to check for faults in the ACC unit itself on the 9-5 (not just from the recalibration program), having never attempted it...tech2??
hopefully someone else with more definitive knowledge will chime in..
My GUESS (and its just a guess) is that even with the blend door arm repair, the female tube may be cracked significantly enough that its causing trouble when ACC calls to blend air,---- or the ACC unit is going wonky.
Have you tried running it on high heat the whole ride (thus keeping the system from ever attempting to bend air)? what temp setting are you calling for? and how cold is external temps?
hopefully something comes up that is clear. good luck
Well that would be great. I understnd the cool air through the center vent, My previous car, Mercedes 190e did the same thing. I don't understand how I can go from the "HI" setting to 82 and it starts blowing cold immediately. Can you explain? or direct me to the page in the owners manual that spells that out? Thanks Mimmi!Your ACC is acting normal.
Thanks for explaining that. Is it normal to have air coming through all vents when the ACC is not on?That is normal, because ACC warms/cools cabin fastest way.
When you select HI, you have full heating and when you lower it to 82F, ACC starts to cool cabin immediately to reach cabin temperature to selected temperature.
This same situation occurs (reversed) when you first select LO and then raise temperature.