A3 1.9 TDI - Boost Problems

[turbodan]

Wonder if anyone can help me with this problem.

The car is a 1999 1.9 TDI (110bhp) and done quite a few miles 159k!

The car was sluggish when i first bought it last year & so got a new MAFF fitted & was running really well, quite suprised how nippy a diesel could be actually, after owning an MR2 Turbo.

A couple of months ago however the boost seemed to have completley gone, every so often the boost will return for maybe 5 or 10 minutes, then just dissapear again.

I realise with the ammount of mileage the car has done, the obvious answer would be that the turbo is ********, but just wondered if it could be a loose pipe or something like that.

ive had an MR2 Turbo in the past & when the turbo went on that, the boost got half way through & suddenly cut out & shuddered, the audi isnt doing this & there is no warning light to tell me there is a problem.

Any help would be appreciated.

Ta

 

[funkymofo]

You got a boost guage? What boost are you reaching when it works and when it doesnt?
Could be a knackered N75 valve maybe, or even the MAP sensor could be triggering limp mode for some reason.

PD150 turbo will bolt straight onto your engine btw so if the turbo has gone its not the end of the world

 

[turbodan]

Theres no boost gauge, its just as if its bypassing the turbo alltogether, and feels like just a normal diesel without a turbo.

I can still hear the turbo whistle though when its supposed to be boosting.

 

[MikeA3]

Sounds like a MAF problem or N75 valve is bunged up - if your able to get boost and then it looses it - it sounds like the engine is going into limp mode

if the turbo was knackered or a hose was loose you wouldn't get any boost at all

 

[turbodan]

Cheers for the comments, i will have to leave it with the garage and see what they say.

 

[VAGMAN1]

could be the problem I had - turbo leaks oil internally over time and this makes a paste which sticks the valves on the turbo. get a full diagnostic done - it's the only way to ascertain exactly what the problem is.

 

[sprout99]

Sounds like a MAF problem or N75 valve is bunged up - if your able to get boost and then it looses it - it sounds like the engine is going into limp mode

if the turbo was knackered or a hose was loose you wouldn't get any boost at all

if not the MAF could be a boost pipe.

You don't want to go for a pd150 Turbo (VNT19 i think)

too much lag

 

[funkymofo]

actually its a vnt17 and there is very little lag without the larger fmic set up that the PD150 golfs come with.
but thats off topic so I'll shut up.

 

[sprout99]

actually its a vnt17 and there is very little lag without the larger fmic set up that the PD150 golfs come with.
but thats off topic so I'll shut up.

sorry!,

i find the pd130 laggy in comparison to the Ibiza 110 tdi I owned in the past.

 

[funkymofo]

really!? I've driven a few 130's and never thought it was a problem,the 150 it is more noticable, but still not too much of a problem. Each to their own I guess

I only suggested the 150 turbo as it is a direct fit replacement(apart from the lower IC pipe) and can hold 22psi comfortably,so will be a relatively cheap and simple upgrade.
Doesnt sound like your turbo is knackered anyway so never mind.

Anyway.....any news on this yet?