turbo not holding boost under load

[bigunj]

hi im new here and this is my first post ..

i own a vectra 1.9 cdti 150bhp, its a 55 plate estate sri fitted with a tuning box

heres my problem -

i travel to leeds and back each day and basically cruise , when im in 5th or 6th gear and i put my foot down usually on a hill climb whether it be my foot or cruise , i seem to hear a fluttering noise ... and a lack of boost unlike i get in the lower gears ,,

so then i fitted a conefilter , which highlighted the problem even more !!

so today i dug myself an old mechanical boost gauge out that reads upto 30psi.. i had a tap in kit from years ago that goes into your rubber induction pipe thats right in front of the throttle body ,, so i took it for a drive and floored it , it goes right past 30 psi upto about 32psi ,..

now when im in 5th or 6th gear and the fluttering sound starts the boost is bouncing between 26 psi and 32 psi , so i think ive either a turbo problem or actuator problem ,, so i ask you guys what do you think .. any ideas and thoughts would be appreciated

[marc vectra sri]

I may have a problem the same when I floor it ya can here the turbo spooling but it's goin on and off hard to say it really

[JJ0063]

I have that too.

[Craig1985]

My friends astra 1.7cdti does this, mainly under loads and low revs 1500/2000 revs.

[paulhb]

Have a word with Nutron send him a pm but if your gauge is accurate then there might be an issue unless you have a hybrid and a remap then 30 psi is too much from what Nutron has told me shouldn't be more than about 23 psi as that's all a standard turbo can handle.

[plasma]

[Critch]

Is it standard apart from filter?

[bigunj]

hi yes its standard , only a tdi tuning box,, i only used the cone filter so i could hear the problem more as it opens up the system .. as for the boost gauge just used it as a guide to show and explain my problem (it wont be staying) .. my boost shouldnt be fluctuating like it is , i understandy your boost backs off a bit , but it shouldnt be bouncing like it is . im sure it isnt the turbo but maybe the actuator/wastegate , just need a bit more help on this as im not 100% sure .. just to make clear its bouncing up and down on the boost quite spasmodically ...thanks guys

[paulvectrac]

your turbos gonna b;ow up soon take that box off for a start even though it onjy adjusts fueling

[bigunj]

your turbos gonna b;ow up soon take that box off for a start even though it onjy adjusts fueling

cheers mate . its allready off the problem was there before i put box on , ive only had the car 3 weeks . and noticed this soon after i bought it , like i said only seems to happen when im cruising , and go to overtake say and you give it a liitle gas ,, something telling me actuator isnt holding shut like it should under higher pressure..?