Passat b5 loss of power at exactly 72 mph

**cluvie** · 29-09-2013,10:52 AM

hi..at exactly 72 mph i loose power its like as if the turbo cuts out and if i clutch turn on and off the engine everything is fine again until i hit 72mph. Ive tried 2 different airflow meters both new albeit aftermarket and still problem persists..ive had it on a diagnostic but no faults appearing..one mechanic reckoned turbo is nackered. i find this hard to beleive as the car pulls like a train till i hit the dreaded 72mph???? The last maf sensor i bought cost me 125euro so it is a good one and bought from a reliable source..very annoying problem as i find it hard to trust the car whilst overtaking..any help or suggestions greatly appreciated..im in southern ireland if anybody is available to do a vag reading for me??? Thanks guys love the site by the way

**zollaf** · 29-09-2013,10:54 AM

which engine, a pd or rotary pump ?

**Doctle Odd** · 29-09-2013,10:56 AM

What did he scan it with?

**cluvie** · 29-09-2013,04:19 PM

we just scanned with a spurios scanner and the fault code was charge pressure control negative deviation p1156...i googled this and it came back as a faulty vacuum actuator on the turbo..i gave all day today cleaning and checking hoses and they all look good..im absolutely stumped as to what the problem is..

**zollaf** · 29-09-2013,04:33 PM

look, i know its a diesel engine but it could be a pd or a rotary pump, now which is it ???

**Doctle Odd** · 29-09-2013,07:53 PM

Ross-Tech: VCDS: DTC Comparison

Originally Posted by cluvie

we just scanned with a spurios scanner and the fault code was charge pressure control negative deviation p1156...i googled this and it came back as a faulty vacuum actuator on the turbo..i gave all day today cleaning and checking hoses and they all look good..im absolutely stumped as to what the problem is..

**cluvie** · 30-09-2013,02:57 PM

i see your point doctle odd

zollaf its the pd engine..thanks guys

**zollaf** · 30-09-2013,03:54 PM

you possibly have a split or slightly perished vacuum pipe. try a new pipe from the take off point on the servo straight to the n75 then to the turbo, thus eliminating the anti shudder and egr valve and see if thats any better. thats what i would do to eliminate a leak.

**JustinM3** · 30-09-2013,05:18 PM

My old P reg was the same, put it down to jammed vanes. Was ok until I fixed the split boost pipe which was robbing boost so avoiding this I guess.

**cluvie** · 01-10-2013,01:30 AM

i get what your sayibg about running a pipe direct to the turbo from the servo via the N75 but whats this N75?? im seeing it in a lot of threads..also i would have to get something to bring the pipe from the servo down to size to fit vacuum on top of turbo..any ideas?