intermittent power loss

[NickVC]

like title says, intermittent power loss. Sometimes the car feels like a 180hp car or so, sometimes even less. no boost leaks, vacuum should all be good. recent forge DV because oem failure. spark plugs, coils, all new.

yesterday no boost at all( happend once), other times i allways hear boost building up, just not enough( accourding to sound)

most off the time it pulls nice like it should be. My first impression would be maf sensor or n75.
no cell or dtc's.

anyone had same experience?

 

[hydro s3]

What year,make and model would help people diagnose what you should try. Mybe try a scan with vcd because even with no light on the ecu might still have codes stored.

 

[NickVC]

sorry, 2001 s3 amk engine. and like said, no dtc's...

 

[<tuffty/>]

What did you use to scan it?

<tuffty/>

 

[<tuffty/>]

...and does it do it from cold?... if so what is the outside temp at the time it does it?

<tuffty/>

 

[NickVC]

delphi professional scanner, cold/hot engine, cold/warm weather makes no difference, or little

 

[NickVC]

slightly rough idle sometimes to, but not like it's fluctuating 100rpm's or so, its less

 

[<tuffty/>]

If you have access to VCDS then I'd scan with that... a lot of scan tools including expensive pro ones don't pick up all codes....

See this quite often sadly... my daughters 2010 Polo (1.6tdi) broke down a while back... VCDS scan revealed a common issue of the DPF pressure sensor... I left the code in there for the breakdown fella to find as we only needed the car to be recovered to a friends garage but his 'professional' scan tool didn't pick up the fault code... so I rescanned with VCDS in front of him to show the fault else he may not have recovered the car...

Makes you wonder how many cars are driving about with faults that are undetected...

<tuffty/>

 

[NickVC]

no immediate acces sadly. i'm close to guessing maf sensor. will be as expensive as going to audi for diagnose

 

[<tuffty/>]

Try the VCDS map in the VCDS section of the forum... there maybe someone close to you willing to scan your car

<tuffty/>

 

[AlexA4Avant]

have you tried vagcar coding on here he is one of the sponsors he is in north London if that helps

Sent from my SM-G930F using Tapatalk

 

[fisher72]

like title says, intermittent power loss. Sometimes the car feels like a 180hp car or so, sometimes even less. no boost leaks, vacuum should all be good. recent forge DV because oem failure. spark plugs, coils, all new.

yesterday no boost at all( happend once), other times i allways hear boost building up, just not enough( accourding to sound)

most off the time it pulls nice like it should be. My first impression would be maf sensor or n75.
no cell or dtc's.

anyone had same experience?

im having the same problems s3 bam some times it boost likes mad some times its flat as anything scanned it with vagcom no fault codes just comes up with dv going to fit a boost gauge change the n75 dv from forge to standard and try and get to the bottom of it we let you know ow i get on

 

[NickVC]

i live in belgium, so 'close to me' won't be an option haha. fisher, let me know i you find something!

 

[fisher72]

will do off work tomorrow so weather permitting going to have a tinker with it

 

[fisher72]

hello nick ive done some investigating my power issues are down to the boost pipe from the top of the turbo to the hard pipe becoming weak over time and detaching itself slightly from the hard pipe so its getting enough to boost and as not to fetch a code up been using a lot of fuel lately so the car as been running rich because of the boost leak changed the n75 and bov but these didn't make any difference hooked a boost gauge up with the boost pipe firmly attached it was pulling 26psi and then tailing of at high revs as it should but as soon as the boost leak started you would only pull 6 psi hope this helps cheers Paul

 

[Erikn89nl]

i live in belgium, so 'close to me' won't be an option haha. fisher, let me know i you find something!

I can have a go, I live pretty close to Antwerp...

 

[NickVC]

hey guys, thx for the input. Actually i got back on power today, after filling up oil level. was close to minimum. could it be that the engine gets more 'knock' and therefore gives less boost and changes timing? had these problem before with opel/vauxhall cars, maybe a long shot, but i did +- 150miles today and the car performed very well