1993 (built 05) 525i auto trans, 257k miles.

Hi, since a few weeks my car suffer from low power/torque at low rpm. Above 2200-2500 then it then takes off with the good power/torque it used to give.

When I noticed it I checked for codes with my Peake reader and there was a code for the camshaft position sensor. I cleared the codes and the code never showed up again. I replaced the sensor anyways but it didn’t cure the problem. (One note is when I replaced this sensor the old one came full of metal dust?)

So I’m wondering what to check as there are no faults stored in the OBD.

One thing to note is that if the car is idling and I press the pedal to the floor the car dies. Then it starts back fine.

I’m suspecting either the throttle position sensor (TPS), O2 sensor, MAF or VANOS. I did check the TPS sensor last winter when I changed the spark plugs and the TPS resistance was fine as in Bentley. O2 sensor was replaced 50K miles ago as well as MAF. Vanos piston seal was replaced 3 years ago as well as I upgraded to Spring loaded stopper for the intake cam and the car has been running well since (it cured the metallic taping from the worn Vanos seal). Crankshaft position sensor was replaced at same time. The only sensors I never replaced on this car is the TPS, and also the Vanos solenoid was never replaced (from my ownership = 8 years).
The Vanos link to that I’m not sure because it is supposed to advance timing at RPM >3000, it should have nothing to do with lower RPM behavior. Unless it is always ‘stuck’ in the advance timing position? Again there are no OBD codes.

One thing I remember now writing this is that the engine began to have a metallic tapping in the Vanos area a few weeks before the power loss issue. Before that the engine was purring fine.

I’m planning to replace the valve cover gasket soon so in the same time I’d visually inspect to see if there is anything wrong.

Thanks for reading and let me know what you guys think!
Alex
1993 (built 05) 525i auto trans, 257k miles.