1.4 TDI 90bhp ATL engine intake manifold flap motor fix (?)

BiggDogg

Member
This maybe premature, but I think I've fixed my V157.

I'd been having the check engine lamp on most of the time and a nasty shudder when turning off for a few months, but otherwise the car was driving fine.
The ATL engine has a different arrangement for actuating the flap which is all electronic. Basically this flap is used for preventing the shudder when turning off the engine - it starves it of air until it stops. There is some EGR functionality too, I believe, which has also caused the warning lamp to light on the otorway occasionally too.

VCDS Lite read:
19559 - Motor for Intake Manifold Flap (V157): Malfunction

P3103 - 35-10 - - - Intermittent

Having read various posts on the subject I thought I'd be forking out £200 for a OEM replacement (part no. 045128063D).

Note that many parts people call it a "throttle body".

See no.11 here:
http://workshop-manuals.com/audi/a2...s_with_engine_code_letters_atl_exploded_view/

The unit is near the coolant expansion tank near the back of the engine bay on the nearside, the right as you look at it.

Before ordering a new one, I thought I'd strip it down and see if I could see anything wrong inside.

Long story short:
It was full of engine oil which collects in the bottom and stops the electric motor working properly. After stripping it down as far as possible, cleaning all the oil out and refitting it, running for 3 days: NO MORE WARNING LAMP AND TURNING OFF AND ON IS SMOOOOOOTH. I think the oil has all come from the turbo, I'm not worried by this as it seems all the TDIs I've owned have always had a fair bit of oil in the intake, post turbo, and the oil consumption is close to zero after 86000 miles. However, it seems that with the 2.3bar peak boost pressure of the ATL engine, and the design of the flap motor unit, that oil mist is going to get inside the thing over a period of time.

Long story long:
Naturally I've taken some photos, this is how you can do the same as me if you fancy giving it a go, but don't blame me if yours turns out differently, my experience is based on doing this just once:
You will need: Large flat bade screwdriver, 5mm hex (Allen) key/bit, T20 and T10 Torx bits, lots of clean rag or kitchen towel, parafin or other solvent for oil.
1. Disconnect the large air pipe which comes from the intercooler by lifting the little raised section in the C-shaped spring clip and pulling the pipe out.
2. Remove the electrical connector by squeezing it together first, and while squeezing, push the latch and change from squeezing the connector together to tugging and wiggling it gently apart. Practice first on one for a different connector which you can actually see if you've not released one before.
3. Remove 3 hex bolts, unit can now be withdrawn.
4. Clean up the case before going further, the next bit may be very messy.
5. Remove the 4 Torx screws holding the cover plate on, it will come loose but will remain held along the diagonal section at the bottom. Expect a little oil to come out.
6. Don't force it apart, jiggle it around and work it, eventually the 2 electrical clips inside will release their grip but you need to BE GENTLE, looking at the design I thinking forcing it will make the clips bite deeper and you may end up breaking it. Maybe I just got lucky.
7. The electronics is all in the lid, and is encapsulated in some plastic compound. The 2 copper connections to the motor assembly should be OK if you haven't forced things and bent them.
8. Clean out all the oil you can get to from both halves, but don't scrub. You need to get the motor assembly out as it is at the bottom where most oil collects. To get the motor out, pull off the cap holding the largest gear on its shaft, then remove the two small T10 torx screws then withdraw the motor and large gear as one. There is a wavy spring washer behind the motor.
9. I tried to get the motor pinion gear off, in an attempt to strip the motor down and clean the commutator properly, but gave up when the pinion wouldn't budge.
10. Instead I swilled the motor out in a jar of meths. This probably wasn't a good idea as the oil didn't really dissolve like I had hoped, falling out of the vents in the end of the motor in globules instead. If I'd have had any paraffin I'd have used that. I shook the meths out of the motor, dried it with an air line then connected it to 12V to check it worked (NB make sure the thing is dry and don't fire to any flammable solvent with electrical sparks!).
11. Reassembly was easy, just a reversal of the stripdown. The pipe pushes in, no need to lift the C-spring clip again.

I wasn't really expecting it to work as the engine lamp lit upon starting up, but there was no shudder when I turned off, and repeating the process, still no shudder - I hadn't cleared the fault code, and was getting late so went to bed.

The next day the lamp did not come back, there was no shudder and having been on 5 long trips now, driven maybe 150 miles, there has been no shudder and no warning lamp.

Please add to this thread if you fix yours the same way, I am guessing that I am going to have to repeat this process in the future at some point, hopefully not for 20,000 miles at least.
IMG_2333.JPGIMG_2335.JPGIMG_2341.JPGIMG_2337.JPGIMG_2332.JPGIMG_2336.JPG
 

kuro

Member
Hi, I have the same problem. mechanic in audi garage says the flap motor is faulty. engine revs are 1050 RPM in neutral. the light is on after the car is not used for more than a week. if the car is driven regularly the light is off but the revs are 1050 RPM. it can be the same problem perhaps?
 

PaulA2

Member
Did you replace any of the seals or did they go back on ok? Nice write up, suspect mine needs doing although I dont get the management light on yet.

Always nice to hear of these no cost options to improve the running of the car. Thanks for taking the time to write it up!
 

BiggDogg

Member
Did you replace any of the seals or did they go back on ok? Nice write up, suspect mine needs doing although I dont get the management light on yet.

Always nice to hear of these no cost options to improve the running of the car. Thanks for taking the time to write it up!

The seals looked OK, and I didn't renew anything. I don't think I'm losing any boost pressure as the power is the same as before. Mine was shuddering for maybe 6 months (about 7000 miles) before the lamp came on. Since there is a strong return spring which the motor pushes against, I think the flap will always fail open unless there is a serious mechanical jam or spring breakage.
Matt


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BiggDogg

Member
Oh dear. The lamp came back on and the turn-off shudder is back after about 600 miles. When I get the opportunity I'll do a second strip down and report back.


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BiggDogg

Member
Oh dear. The lamp came back on and the turn-off shudder is back after about 600 miles. When I get the opportunity I'll do a second strip down and report back.


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Very quick update, I haven't stripped down for a second time yet because the light extinguished again and the shudder disappeared. Whilst this continues I have better things to do, "if it ain't broke don't fix it".


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sof

Member
Great thread.

Had the same problem on my 300.000 km 90bhp. Followed BiggDogg`s description above.

Also found oil inside the motor. Sprayed it with electocleaner and pressure air. Tested it repeatly on a 1,5v flashlight battery and it run nice both ways. Found no wear or damage on the nylon gears. I just cleaned and sprayed with silicone oil. There was also a lot of old hardened dirt and oil around the flap it self. Cleaned it up and deleted the fault code in the cars memory.

The lamp did not come back.


Cheers
Sven
 

BiggDogg

Member
Hi Coolpix, no this flap can't cause the engine to rev up. It closes briefly when you turn the key off, starving the intake of air and bringing the engine to a smooth halt instead of shuddering. It also has a function to do with the EGR but I don't know exactly what it does / when for that function. The 75 bhp TDI has a different system. Matt


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timmus

Member
Hi Matt,

Thanks very much for this thread. Your write-up and photos will no doubt prove to be of great help to many. :)

The 75 bhp TDI has a different system. Matt

The TDI75 comes in two flavours: AMF and BHC. Whilst the earlier AMF engine uses a different anti-shudder valve, the later BHC engine uses the same system. So, your fix does apply to some 75bhp engines.

Cheers,

Tom
 

rob1976

Member
Wish I had read up on this thread earlier, had the same issue and same fault code for the last 6 months, cleared with VCDS and cracked on. It appeared again on Monday evening.... bright orange warning lamp doing my head right in! And I have just forked out £205 for a new one.

I will post pictures of the internal workings of the faulty one, my guess is it will be very similar to the above.
 

rob1976

Member
Full of oil, how does it get into a sealed unit?

I have fitted a new one which has improved the vehicle start/turn off, and the pesky light has gone..... for now :)

Inside.jpg014e54698b95e8a1c6b75b345ac2a9e18e8bbaca56.jpginside2.jpg

Final image shows the Pos/Neg connector covered in oil
 

BiggDogg

Member
Thanks for posting your pics. I'm sorry you saw the post too late. I think probably renewing the thing is likely the best long term solution but having said that, mine's still fine.

My theory is this: The small amount of oil which leaks past the turbo compressor side oil seal and goes through the intercooler as a mist then goes through this valve. Every time the compressor spools up and the pressure goes up from atmosphere to 2.3bar the pressure will try and get into that space inside the inlet manifold flap valve because that will be at atmospheric pressure. No doubt there is a shaft seal or o-ring which tries and stop that, but I guess it wears out eventually. When the pressure reduces, a bit of air will no doubt come back past the shaft seal into the inlet but probably some of the oil will have deposited inside the space inside the inlet manifold flap valve and the net effect is to build oil up inside.

Does anyone else have a theory?

If / when my shudder comes back I might try and disassemble a bit further to find this seal I am imagining - maybe something to try on your old "spare"?


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rob1976

Member
I see your logic, It seems a easy fix to remove all the oil, which is the most likely culprit causing a contact between the electrical connectors. I will have a deeper look to see if there is a small seal on the shaft that the flap is attached to, as you mentioned this has to how the oil weeps into the control.

I must add though, the new one fitted has made a vast improvement to the overall feel of the car, next job is to replace the suspension top mounts.

Thx.
 

BiggDogg

Member
Interesting you've got an improvement overall! I think it's not the connectors which the oil causes a problem with, but instead the contact between the motor's carbon brushes and the commutator.
Matt


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Ricardo

Member
Many thanks to the OP for an excellent write up and photos.

I dismantled mine today, unfortunately the motor is burnt out and feels like a bearings gone in it too. I could smell the motor as soon as I opened the case.

For those attempting this fix, when removing the case lid where the OP describes wiggling it about gently etc the restriction is two copper spades which are connected into two pairs of copper contacts. As you pull the case lid, the copper spades scrape against the contacts. As you wiggle the case gradually parts until it comes away.

Its best to be gentle, but as mine is knackered I pulled the motors coils away firmly which are connected in the same manner and no issues.

The motor is a standard(ish) 12v Johnsons item which would probably cost £10. But one of my coils has disintegrated and the other looks bad too, and as I imagine thats an Audi part - I will have to replace the whole thing.

I would suggest that if you have a judder symptom on shut down or get the error code then clean the valve ASAP to stop the motor dying like mine to save yourself £££. Its a 15 minute job to remove and re-fit the valve excluding the bench time to clean etc. My engine light has been on for 6 months - should have sorted it sooner.

I'll post here with the price, looks like standard VAG is the only option at the moment.
 
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