PDA

View Full Version : Poor performance



rob160
21-11-2012, 02:31 PM
Long story short sort of.
I have a A4 1.9 tdi 130 on a 2002 plate with 235000 miles and its been down on power for over a year.
I borrowed it to a customer for 2-3 weeks and when I got it back there was no boost and going into limp mode with a over boost code on motorways. I stripped the turbo and cleans the vains and hay presto I gradually got power back over a few days.
It feels more like 100 bhp so I want to get to the bottom of it now.
Things iv done are.
Cleaned the vains
Cleaned the EGR and manifold
Replaced vacuum elbow on boost sensor.
Silicon sealed the vac pipe on the tandem pump.
Next job is to strip the turbo again.
Oh when I first start the car and pull off quickly there no boost wile either the vacuum builds or the vains unstick, that's what I think.
Sort to go on but any ideas would be great.

rob160
22-11-2012, 08:02 PM
Any 1

Doctle Odd
22-11-2012, 09:39 PM
Can you scan it with VCDS and post the results? There's a bunch of reasons why these cars aren't boosting some cheap some not. Scan first

zollaf
22-11-2012, 10:10 PM
get an assistant to start the car while you observe the boost controller above the turbo. it should move up under vacuum as soon as the car is started.

rob160
24-11-2012, 04:35 AM
Yes it does but I'm unsure if it moves enough.

zollaf
24-11-2012, 09:07 AM
19 mm is how much it should move. if its not 19, it very close to 19. anyone confirm 19 or be more exact ??

adamss24
24-11-2012, 11:06 AM
It could be a boost control valve or the MAF. I would discount the turbo IF you cleaned it properly before...

rob160
24-11-2012, 12:21 PM
Will check it out in the next few days hopefully

rob160
27-11-2012, 09:44 AM
Had the battery tested and its 86% good. Got to be the starter.

rob160
06-12-2012, 09:17 AM
Sort wrong tread ha ha

rob160
06-12-2012, 09:22 AM
I'm thinking it a vacuum problem.
It could be boost valve or vac pump.
Was wondering if it could be the vacuum reservoir, maybe it's not holding pressure.

rob160
07-01-2013, 09:31 AM
Righty then I changed the vac pump and no difference the took off the boost solenoid and the filter for it was clogged so took it off and also blow out the tubes with a air line as the solenoid seemed blocked and no difference what so ever. Aaaaaaaaaa

rob160
07-01-2013, 09:37 AM
If I sit the and just rev it the back chatter sounds like dearth vader breathing.
When I first star it up and start driving, if there's no boost I can hear the difference it's like a howling sound from the air box and turbo area until I get boost.

Doctle Odd
07-01-2013, 09:52 AM
3/4" in old money's close!
19 mm is how much it should move. if its not 19, it very close to 19. anyone confirm 19 or be more exact ??

Doctle Odd
07-01-2013, 10:14 AM
A VCDS scan will tell you if it's an electrical problem like a sensor, it will also tell you if the turbo is boosting. Are all the pipes and hoses tight with no cracks or splits? Can you disable the egr, Just pull the small pipe bend it over 180 and tie/tape it, then cover the nipple with a bit of tape. Hearing the chatter would help can you post a video. My advice is to scan it first it's quicker and cheaper than randomly changing things and when some components are changed if the fault code is still there it makes no difference

rob160
09-01-2013, 09:36 AM
Iv scanned it a few times in work with a snap on scanner and it over boosts even on tick over and don't normally get a fault code.
What will disabling the EGR do as iv ran it in the past for long periods with no difference to performance, can give it a go though.

Doctle Odd
09-01-2013, 10:01 AM
If a car is over-boosting there's a problem and a full scan with something like VCDS or VAS-PC is needed. Ross-Tech: VCDS: DTC Comparison (http://www.ross-tech.com/vag-com/dtc-comparison.html) to get a full picture. I don't think it's over-boosting and going into limp mode I think you have a split or cracked hose or vacuum pipe on the induction side. Try to get live data, the EGR allows dirty air into an engine personally I hate them, you could clean the EGR and inlet manifold as well

rob160
09-01-2013, 09:54 PM
EGR and inlet been cleaned

Doctle Odd
09-01-2013, 10:23 PM
OK you need a scan and record live data