Google litt på vanos symptomer... se f.eks denne http://forum.roadfly.com/threads/11027162
Sensorene er det jo lettest å bare bytte... ellers vet jeg noen ohmer dem... men med en periodisk feil så vil nok ikke dette kunne oppdages med et ohm-meter.
Dette er klippet fra linken over her:
The M52TU engine (99-00) has one further malfunction symptom which is far from subtle. It occurs on cold weather cold engine starts and takes the form of repeated engine attempted stalls and possibly a complete engine stall. The engine rpms drop dramatically and then recover. This then repeats after a few seconds of steady idle. The problem can be more definitively diagnosed by disconnecting the vanos intake or exhaust solenoid electrical connector. If the engine stalls seize then the problem is due to the vanos. The intake solenoid electrical connector is easier to access and is located to the left (at hood) of the oil filter canister. It’s at the end of a metal cylinder (solenoid).
Skulle det være Vanos så er her også en god artikkel: http://forum.roadfly.com/threads/12264306-Vanos-seals-solution