Main IndexAuto Repair Home Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN









Search Auto Parts

RPM fluctations when car is idle Audi A4 2011


  Email This Post



mgaspersic
New User

Nov 28, 2014, 2:08 PM

Post #1 of 5 (3600 views)
  post locked   RPM fluctations when car is idle Audi A4 2011  

Hi guys,

I have been searching for a while on this forum for any usefull informations about my problem, but I can't find anything. I hope someone could help me. I have big problems with RPM fluctations when car is idle. While car is driving everything seems to work fine, fluctations only occur when car is idle.

Here is video of my problem: https://www.youtube.com/watch?v=5kMfWYH-tmA


If I add more power to engine, it's running ok and also there are no fluctations when I drive car OR even there are no noticable fluctations when car have more than 1200 RPM. Also none of any strange sounds can be heard from engine. When car is idle, rpm fluctates from 700-1000 rpm also even more if I turn on A/C like 600-1000. Fluctations have similar feeling like car would run out of gas, but it don't stops. I'm sure, there is/was enough gas inside. When problem occured, car had almost half of a tank.

Car has also been tested with VAG-PC software and report was:

Address 01: Engine Labels: 03L-906-019-CAG.clb
Control Module Part Number: 03L 906 019 AL HW: 03L 906 019 AL
Component and/or Version: R4 2,0L EDC H34 9097
Software Coding: 0A194012232403080000
Work Shop Code: WSC 06324 000 00000
ASAM Dataset: EV_ECM20TDI03L906019AL A02008 (AU48)
VCID: 75E5E5E76701
4 Faults Found:

4698 - Function Restriction due to Received Malfunction Value
U1113 00 [032] - Open or Short to Plus
4699 - Function Restriction due to Received Malfunction Value
U1113 00 [032] - Open Circuit
5175 - Fuel Pressure Regulation: Regulation Discrepancy
P1065 00 [109] - Short to Ground
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 160206 km
Date: 2014.11.26
Time: 17:17:55

4278 - Implausible Data Received from ABS Control Module
U0415 00 [032] - Short to Plus

Readiness: 0 0 0 0 0

Probably only third message is related to this problem (Fuel Pressure Regulation). There is also a date and time described and matches the time when I notice error.

I am not sure what's going on and error message which vag displayed to me is to much general to me to locate the problem.

What could cause rpm fluctations in my case? Is it safe to drive with fluctations? is it possible to damage engine? I know, that there could be number of parts which could fail, but I don't know where to start. I don't want to drive car to audi servis yet.

Car is Audi A4 2011 TDI B8 88kw 120hp, engine type is CAGC, 160.000 km.

Mgaspersic


mgaspersic
New User

Nov 29, 2014, 3:23 AM

Post #2 of 5 (3566 views)
  post locked   Re: RPM fluctations when car is idle Audi A4 2011  

Any help will be appreciated, I don't know where to start looking for a problem :/


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Nov 29, 2014, 4:27 AM

Post #3 of 5 (3561 views)
  post locked   Re: RPM fluctations when car is idle Audi A4 2011  

Quote">>I don't want to drive car to audi servis yet.<<"
I'm not so sure you are going to get tons of help from PC reading vs what an Audi dealer's readings could do for you and if you buy these type vehicles you will end up acquainted with them.


Can wait for others to suggest away but clearly the car can't hold a proper idle and info suggests fuel delivery issues.


Video too close up sport. What I see is it was cold, low on fuel and your MIL (malfunction indicator light illuminated) I think and the RPM needle unable to stay steady. That and enough miles/kilometers that any lack of strict attention to proper maintenance if not followed to the letter is at a time to show itself as troubles for not doing it.


The basics are take fuel pressure reading to see if in spec and clean throttle body as it's IAC or equivalent clearly can't hold the idle. Using A/C is a load and it isn't compensating for that load either so that's the area of trouble but the exact fix still not targeted and you may need better info and info from the dealer or Euro equipped code readings more that that.


Sorry on my part not much help for you. Would need more info than that. So, best I can say is hurry to find the source of this problem as it will very likely domino into more problems than it has now over just this,


T



mgaspersic
New User

Dec 8, 2014, 1:22 PM

Post #4 of 5 (3513 views)
  post locked   Re: RPM fluctations when car is idle Audi A4 2011  

It was failed fuel rail pressure sensor. He should produce from 280-320 bar of preassure but after some measurement we figured out that he was producing more than 500 bar of pressure while car was iddling. After replacing unit, car starts to work normaly.

Thanks for your help!


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Dec 8, 2014, 1:40 PM

Post #5 of 5 (3507 views)
  post locked   Re: RPM fluctations when car is idle Audi A4 2011  

OK - Sounds like you've found and fixed it so will close up thread unless you request this one to be re-opened by any moderator,


T







  Email This Post
 
 


Feed Button




Search for (options) Privacy Sitemap