Occasional boost cut out

[S3 L33]

Hi,

Ive had my '99 S3 for nearly a month now and all was good until i took it in for a service. Now sometimes when i put my foot down it will hold boost then cut out for about 5 secs (no power when foot is down). I took it back to the garage and they plugged it in and it said there was a faulty maf. I replaced this and all was well until last night i put my foot down in 3rd and it done it again, only this time it lasted a bit longer. I slowly got it to my friends house round the corner where there was like a burning smell from somewhere and then engine was struggling to rev (while stationary). A minute later the car was fine and i was on my way again. This is startin to bug me as i was hoping the new maf would sort it but its fine most of the time just occasionally does this in boost??

Any help much appriciated

 

[Clach]

have you tried a new DV...the first set of symptoms seem to suggest that, or look for a split or collapsed breather pipe under the Throttle body

 

[S3 L33]

thanks for the reply, its got a not too old forge dv on the car so wouldnt have thought it was that, as for the breather pipe under throttle body ( i presume you mean the hard plastic one) it was cracked when i got the car and got the garage to replace this with the service, but the car ran perfect before with the cracked one?? weird

 

[Clach]

Vag com is the best option, any codes since the service?

 

[S3 L33]

The only code after the service was for the maf which has been replaced

 

[Clach]

what was the code, as alot of things can cause the MAF to throw a code...I had a dodgy coilpack and that indicated everything under the sun!!!

 

[S3 L33]

not sure of exact code, it cant b nothing too serious i hope as it doesnt do it all the time but when it does its like the car doesnt have a turbo then a bit later its fine

 

[jamieface]

had a similar fault which turned out to be a faulty coil pack, would hesitate at around 3k rpm like a stutter then take off, sometimes it was there sometimes not. The coil pack eventually went after about a week of normal driving. I changed all mine for new and kept 2 of the old with a matching part code as spares. (just in case !)

 

[S3 L33]

cheers jamie just been lookin through a few old posts and the coil packs often turn up. how much are they each? would it not be logged when plugged in to VAG?

 

[markyp2002]

I believe coil packs are around £30 a piece and fairly easy to change yourself. I currently have this very problem. Boost seems to die and struggle at around 3-3.5k rpm.

I have it in at Midland VW at the moment, so should have a verdict tomorrow morning, so ill keep you posted.

 

[S3 L33]

ok mate let me know how u get on, ill take it back down the garage tommorow see if any new codes have come up, was slightly concerned about the burning smell yesterday when i was trying to rev it in neutral but have not smelt it since

 

[markyp2002]

Thats possibly because youve melted whatever was burning haha! Ill let you know the verdict tomorrow, have a feeling its something to do with either a split hose or the DV!

 

[markyp2002]

Well, had a call from midland vw and its all good news. There was merely a poorly fitted pipe at the back end of the engine bay somewhere causing the car to misbehave, and a dodgy N249 was being a bit mischevious too. So a refitted hose and a bypass N249 later, all is well Not bad for £30

 

[Clach]

always good to hear that some garages can be honest...I think alot of mechanics sense fear and go for the big solutions. I think Audi must do a training course in it!!! - Look for the nervous twitch, and the anxious voice, and we can get £700 quid out of him no probs...

 

[S3 Rav]

i can vouch for midland vw great honesty by jody