CPS Diagnosis

Hello all

My vehicle (2001 330CI automatic with 54000 miles) has developed a low RPM and rough idle issue that I can't seem to figure out. There are no codes stored.

The problem only happens once the car reaches operating temperature, at wich point the RPMs drop to around 500, and gets very rough, almost to the point of stalling.

The dealer is telling me that all is fine with the car, and they can't reproduce the problem.

So I went and got a second opinion from a fellow 3 series owner, and he tells me that it's a common problem for our cars, but nothing too serious

he told me that it could be the camshaft/crankshaft position sensor. He was almost positive that was the problem.

My questions are.

can the symtoms my car is having be related to a bad camshaft/crankshaft sensor?

How many of these sensors do our cars have? I hope it's not 4 of them like the O2 sensors.

And, should I change all of them if my car is not showing any codes?

I would really hate to waste money on these sensors for them to not be the problem.
so I'm going with the process of elimination through the responses I get from this forum

Thanx in advance for all your responses.