hi, probably been asked before, but i feel my loss of boost is different to other horror stories on here. my car runs sweet, but the boost is just minimal.ive checked all hoses, cleaned the solenoid, and ordered a new maf just incase. if the maf doesnt cure it, and i buy a new actuator and that doesnt cure it,what else could it be?iive also taken the hose off the actuator and blocked it up, just to see if it boosted stupidly, and it did, although i dont know what this means thanks in advance

steve

 

The most likely culprit for this symptom is an airleak post turbo. Check all hoses/pipes/unions 'twixt turbo's compressor outlet nozzle... via IC... and through to the IC to TB hose.

 

thanks for that. i had it at the garage yesterday just to get all that checked, and theres nothing a miss anywhere.but as i say, took off the hose from the actuator, so the turbo was running at maximum, and it were boosting like a good 'un,just dunno what this points to though.the guy at the garage said, even though no fault codes, he thought it were worth changing the maf, probably wasted me money like

 

That w/g test is proving that the turbo itself is spooling correctly (based on your anecdotal evidence), so the turbo's CHRA and/or w/g penny flapper isn't broken/knack'd in any way.

It could well be, then, that the actual w/g actuator's spring or diaphragm is weak/broken/split etc...

 

i were sort of thinking that. is it best to just buy a new one?or can they be rejuvinated?thanks alot mate, youve been a big help

 

I'd be inclined to get a replacement w/g actuator for your particular turbo model and try that. They can be had on eBay 2nd hand every now and again (or try classifieds on here, etc.)

Which MY/variant do you have (or turbo, if you already know)?

 

not sure on engine but its a td04 turbo

 

Excellent! Check on eBay - there's normally quite a few w/g actuators for that turbo, on there for sale!....

 

thanks alot im off to have a gander,cheers