Motor for Intake Manifold Flap V157 Malfunction P3103

[Bubbauk]

Hi Everyone, I purchased a 2005 a6 C6 2.0TDI 140bhp with about 70k miles a couple of months ago and it has an intermittent fault with it, the car has drove 100% since I got it but occasionally the EML will come up and once read it shows the above fault, this is when read by my mechanics snap on diagnostic tool but when my friend read it with his cheaper tool it shows up P2108 but looking online this seems common. When my mechanic looked at it he thinks that there is an EGR delete kit fitted but there is also a vacuum hosing missing from something that connects to the intake manifold which I think has something to do with the EGR valve? I have included some pictures below. Also the light seems to come on after I have stalled the car, I am not sure if the car stalled because of the fault or not but I have been driving for over 10 years now and I very rarely stall, I thought it could be with this being my first diesel but I thought diesels should be harder to stall?

IMAG1237.jpg - Google Drive
IMAG1236.jpg - Google Drive

Can anyone provide any information on what has been done to the car and what I can do to stop the light coming back on?

Cheers
David

[Bubbauk]

Hi, can anyone provide any information regarding this? I am not sure where this vacuum hose is meant to be going, I have tried looking for diagrams to show but its hard to tell, also the pip that is missing from the EGR i think, it seems very strange.

Regards
David

[inspectorman63]

I think your EGR should have that top broken hose connected down to the ??crankcase?? Those more expert in this engine than me will tell you but it's definitely missing. So you have a hole to atmosphere in your crankcase and a hole in the top of your EGR. Stalling is the least of your problems. Check back with the seller - the problem would have been present at the time of purchase, then you're entitled to ask for a repair or replacement free of charge. It's not simply fallen off in the last two months.

[swalker]

With regards to stalling from what i have found, yea diesels are harder but, a petrol you can catch a diesel will just stop

[Bubbauk]

Hi, I can see where that pipe is meant to go and there is a cover over it which has a VW logo on it. I cant find where the breather hose is meant to be coming from, it looks like from underneath the front of the engine somewhere.

Regards
David

[Rob69]

Hi, I'm not familiar with that particular engine but it looks like someone has done a pretty crude egr delete by angle grinding the hot gas inlet to the egr cooler off. There should now be a blanking plate down by the turbo where the other end of this pipe was connected, as per the pic from inspectorman. Unless the egr was deleted from the ecu, your ecu will be trying to control the emmissions by operating the egr valve, but because the pipe has been chopped off the intake will be drawing in fresh air or blowing out charge air, and the v157 might be all over the place trying to control things,, possibly giving your recurrent eml.
The missing vacuum hose off the actuator diaphragm in your second photo looks like it is going to the anti shudder valve or intake flap runner. I also think this 2 litre engine has intake manifold swirl flaps operated by the v157 intake manifold flap motor, check the flap runner is free to rotate as rhe flaps get fouled up. Someones been messing about trying to do away with the egr but created more problems.
Hopefully there will be an expert along to verify, but that is my take on things.

[imtattoo80]

That missing vacuum pipe is for intake manifold swirl flaps . See from photo.
Swirl flap position is adjusted by an electrical or vacuum-activated servo mechanism which is under the control of the engine management system. In a typical implementation the flaps will be closed at idle speed, creating additional turbulence in the intake. As engine speed increases, the flaps are gradually opened until, at around 2,000 rpm, they are parallel to the airflow and present virtually no resistance. Their purpose is to ensure that the air entering the cylinder is sufficiently turbulent for good fuel-air mixing even at low engine speeds. This aids in reducing certain toxic emissions and may also improve low-end power and torque
.s-l1600.jpg
And this EGR delete ..how its done...Just badddddd.

When i had P3103 - Malfunction - Intermittent ..Then it was Intake Manifold Flap Motor it self.(v157). Inside the motor these contact brushes where little worn. So i opened all motor ,cleaned brushes, bent them little to hold harder against shaft and problem solved. But also fault can be something else wrong inside it.

If you turn off your car ignition will your engine just stay quiet or it stops with shakes..vibrating ??
Maybe yes that p3103 is something to do with egr---bad delete. But if car still shakes,vibrates after ignition is turned off..then V157 is bad. Car must stay just quiet.

[Bubbauk]

Hi, thank you for the reply.

What should I do to rectify this bad EGR delete? Will it cause any problems, should I connect up the EGR again or is the delete the better option?

Do you know where the other end of that vacuum hose should go? I have some spare hose in the garage so i will take a look this weekend to see if I can see where from under the car but would good if someone knew exactly.

I think sometimes the car shakes after shutoff but only sometimes, I also noticed the car idles at about 950rpm which seems high to me.

Cheers
David

[inspectorman63]

You have been sold a defective car. Get in touch with the seller and get him to sort it.

[imtattoo80]

I really dont know if its better to keep this egr thing as it is or get it done better way. Most important is that it must be done in car ecu aswell. Lets hope it is. Maybe someone can tell you how to check that. I still drive with EGR and i leave it like this. There is alot of different opinions about egr ....i keep it. I dont think that if i blank mine will give me any better fuel economy or anything..runs with cleaner air and thats it. Short term average in city i have up to 42mpg and on motorway 65mpg. good enough for me.took photo maybe week ago.16602615_1189326381188269_4567285203361209320_n.jpg
About this Vacuum hose- it must go down to the engine driver side and get connected to one of two vacuum solenoid. Dont know which one but probably you will see where is pipe missing-hangs or somehow blanked(possible that just with screw) There is 2 these valves and 1 turbo boost control valve (n75) N75 i think was closest to the radiator.
See from photo how that solenoid looks....im not sure i found right picture but they are almost same.....plastic unit with electric plug and hose inlet and outlet.s-l1600.jpg
Once you under car you probably will see then easily. Maybe this hose was just forgotten to reconnect and is still somewhere there.
Not sure about higher idle rpm. I heard that some people programmed Ecu to hold higher rpm to get more stable idle.
Would be good if you can somewhere run VCDS output test for Intake Manifold Flap motor(v157) and see if operates every time. Mine operated on first run ,,with second one little and after that nothing. Done only some little noise. Weak connection from brushes. Also you can disconnect inlet hose from Throttle body and see if you can move flap in it . It must be open positsion with engine off. Try to close it and see if moves nicely.If no ,gets stuck or is stuck already then must be damaged gear in it..like Toothed wheels . Its spring loaded and must pop back open it self once you close it by hand.
Of course check for wires,connector.

Ok. i hope you understand what i said. Thats alot of writing. Let us know what you find.