rabskyline

wife has got a golf se tdi 1.9 estate on a 2001 y plate with 144k miles. it loses power above 2300-3000 rpm as if turbo isnt working but i know its fine. there are bubbles in the clear fuel line leaving the filter ( just changed with o rings too just to check and air filter too) to the pump. could this be the bother ?? idles runs and drives perfect apart from this...full dealer history from new..just cant afford to pay dealer rates for a obd diagnostic only to tell me it aint an electronic fault..any ideas??? took off the air mass meter too as per vw parts guy aswell but no change.

RAMP

Hi mate,Check the EGR valve and all pipes to and from it sometimes the valve itself needs takeing out and cleaning as they can completely block up and restrict the recirculateing air,this is a common problem on a lot of the modern diesels,I have had a hose on the EgR valve circuit on a passat kink before and it felt exactly like the turbo doesnt work at all.

rabskyline

cool, will remove it tomorrow ! whats an n75 valve and a vnt ?? been on the tdi forum and its american !

brickboy

n75 is the solenoid-operated vacuum switching valve that controls the turbo's variable nozzle (VNT) mechanism.

I would suspect the Mass Air Flow (MAF) sensor, classic case if it idles OK but won't pull above 2K.

Chip Sengravy

I had a caddy tdi of the same year that did this. does switching the ignition on and off cure it temporarily?

turned out to be something to do with a vacumn hose.

RichCTR

As above try disconnecting the MAF sensor and try down the road it may bring the EML on but a few start stops should reset itself.

BTW. Its in front of the air box assembly and should just unplug.

rabskyline

done the maf thing today as i had heard this from parts guy at the dealer. still the same...going to check the egr as i seen some pics of these blocked ! absolutely choked to the brim !! like a clogged artery ! an all hoses wil get checked too...was told the bubbles are nothing to worry about !!