Leaderboard

Have you looked to see if the AC compressor is running when this occurs? The system may not require the defrost to be selected. AC helps to dry the air making the heat more efficient. For all I know that new of a model may have humidity sensors that will elect to run it in other modes. In any case there is NO adjustment for RPM under any condition. The system is 100% electronic. The ECU and TCU work in tandem to decide what engine RPM is applicable. If there are no warning lights or other indications of a concern from the computers on board you will just have to assume it's normal programming. And if there is a problem, no one here can help and there's nothing you can do yourself either. It would have to go to the dealership and be diagnosed with a Subaru Select Monitor (SSM). GD

It's because you are in defrost mode and it's running the AC compressor. The ECU decides how much RPM the compressor needs depending on temp and pressure sensors in the system. You have a CVT transmission and a DBW throttle control. If this was not as intended it would throw codes. GD

I can’t fathom how you guys over there manage to break so many of these oil pumps. I’ve done three or four oil pump removals each from a different engine without issue. All the best with finding one over there! Cheers Bennie

Couldn't hurt to change the oil and I'd check inside the car where the cable hooks to the pedal. It is known to crack in that location and can cause the issue you describe.