Neighbour has a problem with his VW tdi van
2001 model year
T4 Version
88 Bhp
Mileage is approx 190.000 miles

Starts and idles fine but He's saying it lacks any real punch and its almost as though there's no boost

I've read the codes and there's none present or pending
I've also recorded the live data and i'll have a look and see if there's anything obvious


I'm no Diesel expert so where to start ?
Was thinking of checking all hoses to start with....

ANY advice appreciated


Thanks

is the waste gate stuck open ? has it blown a boost hose off? is the impeller shaft stuck eg turbo is f***** ? check for boost pull pipe off of the blower

[Edited on 2/10/12 by imp paul]

Diesel Pump Timing?

is it a 1.9 or 2.5 5 cylinder? we have 4 of them at work

Silly question but does the van get a good run often? I got mine from a guy I work with and before I got it all it ever did was about 1 1/2 miles in the morning and the same in the afternoon and it coked up the cat quite badly and had the same effect but at that point it was about 7 or 8 years old and had only done 38k! Once he 'decatted' it it was much better. The first week I got it I put injector treatment in and did 350 miles on the motorway at high revs and it smoked like mad but it made a massive difference!

Check none of the boost pipes are perished

Holed intercooler can you hear a hissing. Other problem is that its a T4 not a T5 lol does it show Im a T5 owner

I'll second a leaking intercooler pipe or the intercooler itself, anything else with ping up a code

my vivaro lost all mid range poke, turned out to be air flow meter, which apparently doesnt give a code.

[Edited on 2/10/12 by JoelP]

If it's an 88bhp then it's a 5cyl TDI, the above suggestions are all good to look at, but I'd look at the airflow meter on the intake pipe between the air filter & turbo. If it plays up but stays within the limits of operating range it'll probably lack power but not give a fault code, if you unplug it then the ECU will calculate the approximate value & be closer to right than the faulty sensor was so it'll run better disconnected if the sensor was faulty. This seems to be common on many modern diesels.
Also if the intake pipe between sensor & turbo had a leak (need to be a decent size hole to make a difference much above tickover) then the engine will get air that the airflow meter hasn't seen & it'll have a similar effect as a faulty sensor.


ETA, JoelP beat me to it!

[Edited on 2/10/12 by hillbillyracer]

chq all of the small vac pipes

Thanks everyone for your input

I'll have a poke around and try some of the ideas mentioned

Thanks again

I'm sure I've heard of the wastegates on these sticking?.... Drop off the actuator off and give the operator arm a wiggle.