318i se e46 Problems !!!!!

I own a 1999 e46 316i SE and having similar problems

When starting from cold all is fine, and if i leave the car the revs will be perfectly fine, when the engine warms up the rev counter starts dancing up and down & you can feel the car shudder engine vibration.

the engine runs perfectly smooth if i press the accelerator seems like all four cylinder are operational and recently it had a new airflow meter installed by my local bmw dealership, ££££££££ :banghead:

When the car is stationary the rough idle starts to get on my nerves:screwy:

The diagnostic check on the car revealed no faults at all, i have cleaned the throttle body, new air flow meter, new air filter and new spark plugs but still the car is not right

any suggestions will be helpfull........as the dealership is just a stealership with £200 an hour to diagnose any electrical faults :shakehead:shakehead:shakehead

and can some one please point out what is a PCV and where is it located?

Has someone had similar problems like my car and what did they do to sort it out ?

thank