03 325xi Idle Surge
Hi all, I have an 03 325xi that is surging when coming to a stop/idle. Right around 1k RPM it will surge quickly 500RPM and settle out. I know there are a few threads out there on this topic.
Ill be checking codes and look for leaks, but most of that has already been changed and no check engine lights.
One thing I do need to do is replace the thermostat as it threw a P0128 (I know I just said it hasnt had any check engine lights, hasnt had any new check engine lights) and the engine is running very cold with the winter temps coming in.
Is the most likely cause related to the fact it needs a thermostat? Also thinking about changing the VANOS seals while I have the mechanical fan out.
Any info is greatly appreciated.