I recently bought an ST170 and keep reading about there being hoplessly down on power. Mine seems quick enough but im not sure if i have an issue with my VVT. It does not seem to kick in till 6250+rpm when it should be at about 5000rpm, what gives me this impression is when at WOT approaching 6250rpm you can hear a distinct engines note change which im guessing is the vvt, you can hear the standard induction noise then at 6250rpm+ it almost goes quiet as the engine noise changes completely. Is this right and is my VVT kicking in too late, can this be rectified?

 

vvt works on oil pressure, if the little filter on the gear for the vvti is clogged that could affect it, have you had regular oil changes?

 

Literally just bought the car, its got a full service history and when i dipped the oil in the show room it was brand new, as was the air filter and spark plugs. Is there a way to check this filter on the VVT? The oil pressure guage is showing a very healthy just over 1/2 on tick over and goes up to 3/4 on full load. car has done 49'800miles on a 53 plate? only issue i have had with the car was finding a swimming pool in the passenger footwell yesterday!! Pollen filter i guess, another thing to sort out

 

Its not the throttle body either as i get 100% wide open throttle so no adjusment required

 

Im not 100% sure about this, but im presuming all vvt setups are similar.

 

It could be the variabel inlet tract sticking. This is quite common.