I've noticed over the last several weeks that my '96 I30t's temp control is not stable anymore. At a setting of 72 it may blast out hot air; at 78 it may be rather cold inside. Moving the temp several degrees does make it better. And then the next time the car is started, it actually matches output with the temp setting again, and acts normal for a while.
I know the unit can be adjusted so the set-point matches the output, but I don't need that. It just isn't always keeping the temperature that's set, and it is just as likely to be too hot as too cold.
(I saw where the sensor may have an air tube on it that samples ambient air temp. If the tube has come off, the sensor won't work and the unit will ocillate between too hot and too cold. This isn't exactly what mine is doing, or else any ocillations are a longer period than I wait to make my own adjustment.)
So, are there any diagnostic modes on a '96 that I can enter to check for operation and sensors?
The baffle doors sound like they work normally. Could the coolant valve under the hood be sticking and cause this? I've only noticed the problem since it got cold. A/C operation was stable.
I am not far from selling the car, I don't want to put a lot in to fix this, which I'd have to do if it gets worse.
Suggestions?
JM