fluctuating boost??


May 17, 2002
whats up guys i was wondering if a cracked header can cause a fluctuation in boost??? it usually happens from 3500-5000 rpm. its set at 15 now and it will drop and rise from 15 to ~11-12 PSI. the header on my car is most likely cracked all the way around from what i can see. if not could it be vavle springs??? motor has 100K on it and its a 87 GN. thanks for any help.
Sounds as if your wastegate puck may be fluttering. You may want to look into an HD actuator.

well i put in a HD actuator that i bought off a fellow board member, and i still have the same problem. it happens more whne im not at WOT more like 3/4 throttle but it does happen at WOT too but less severe. at its worst it will go from 20-15 PSI and back up again. shoudl i just buy a new HD actuator or maybe i was thinink it might be one of the hoses that has a small hole in it or something??