Make a donation

Author Topic: ASV/Intake Manifold Issues on Diesels - The Diagnosis  (Read 6996 times)

Offline Matto

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 24
  • -Receive: 112
  • Posts: 1886
  • My Ride: http://www.mk5golfgti.co.uk/forum/index.php/topic,37071.0.html
ASV/Intake Manifold Issues on Diesels - The Diagnosis
« on: November 24, 2013, 11:46:04 am »
I have read on here of people having issues with the Anti-shudder valve (ASV), also known as the Intake Manifold Flap. It is an issue where the small plastic cogs inside break causing the flap mechanism to jam. This in turn blows the fuse and throws a fault.

Recently a mate's car had this issue which gave me chance to do a little investigating. He had already replaced the ASV at this stage but was still getting the EML. This is is scan and probably what others may see when the ASV decides to die.

3 Faults Found:
19558 - Motor for Intake Manifold Flap (V157)
            P3102 - 000 - No Signal - Intermittent
             Freeze Frame:
                    RPM: 798 /min
                    Torque: 46.0 Nm
                    Speed: 0.0 km/h
                    Load: 0.0 %
                    Voltage: 13.98 V
                    Bin. Bits: 11000100
                    Torque: 158.0 Nm
                    Torque: 0.0 Nm

19557 - Motor for Intake Manifold Flap (V157)
            P3101 - 000 - Open or Short to Ground - Intermittent
             Freeze Frame:
                    RPM: 819 /min
                    Torque: 44.0 Nm
                    Speed: 0.0 km/h
                    Load: 0.0 %
                    Voltage: 13.98 V
                    Bin. Bits: 11000100
                    Torque: 158.0 Nm
                    Torque: 0.0 Nm

17075 - Fan 1 Control Circuit
            P0691 - 000 - Short to GND - Intermittent
             Freeze Frame:
                    RPM: 798 /min
                    Torque: 48.0 Nm
                    Speed: 0.0 km/h
                    Load: 0.0 %
                    Voltage: 13.83 V
                    Bin. Bits: 11000100
                    Temperature: 44.1°C
                    Duty Cycle: 9.6 %

Readiness: 1 2 0 0 1

This was on a a MK5 Golf GT 140 (BKD). I did some digging around and found that it would blow the fuse when it jammed up (Fuse 8 in the engine bay). So checked that and found it had blown. Replaced and cleared the faults and all was well again.

I asked if he had the old ASV as I wanted to take it apart to see what actually fails. This gave me an opportunity to get some photos so those on here can see inside one if anyone was interested in why these things fail.

There is only one way into these unit and that is to prise the grey metal lid off with a screwdriver. When manufactured it is put on the peened over in a few places to hold it in place.

Once opened I could see straight away what had happened. As suspected some teeth had broken off the gear (arrowed) that drives the flap causing it to jam.



And another.



Recovered the 2 broken teeth.



Where they came from.





Another photo of the inside.



I think I made have also found out why these fail. Once I managed to get the lid off I found all the inside was full of that black oily residue you get in the TDi intake. Was loads in it as you can see.



I believe this oil is forced by the seals on the shaft of the manifold flap due to being under positive pressure. This then causes the plastic to go brittle and break. Unfortunately I would say this cannot be repaired and a new one is the only real way of sorting it.

Hope this may have given some an insight and a reason as to why you have just had to fork out for a new one  :happy2:

Offline bacillus

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 3
  • -Receive: 447
  • Posts: 6296
Re: ASV/Intake Manifold Issues on Diesels - The Diagnosis
« Reply #1 on: November 25, 2013, 01:58:58 pm »
Great info...   :happy2:
Without traction power is nothing!

Offline juggernugget

  • Newbie
  • *
  • Thank You
  • -Given: 0
  • -Receive: 0
  • Posts: 1
Re: ASV/Intake Manifold Issues on Diesels - The Diagnosis
« Reply #2 on: June 22, 2021, 03:18:58 pm »
Hi there. So I have the exact same faults on my 2005 Audi A3 TDI. I saw they actually make repair kits now online for that plastic gears. Not sure that is even worth it when I can get a whole new one for about 100 EURO.

So, question if you don't mind. I have the codes of course, the check engine light, and the fan fuse keeps blowing. But, I also have some weird symptoms that I'm not sure are related. Maybe you can share your opinion. If it's really cold out, the car is slow/hard to start to the point where it is draining the battery. Especially if not driven far afterwards to get a good recharge, it might need a jump. During HOT conditions, especially a crank while the engine is still hot from previous drive, there will be a shudder from the engine bay. Sometimes if trying to crank really soon while engine is very warm, like after getting fuel, it will be slow to turn over and then a shudder. And I mean a decent shudder that will turn some peoples heads if close by.

What do you think? Possibly related? Maybe the flap is getting stuck to where it's getting just enough air but not enough?