EGR valve clicking/hunting

[Kleinxv]

Hi I have a 170 TDI BRD engine the EGR valve has all of a suddently started clicking/hunting and sounds very metalic anyone got an ideas as to what could be happening.:1zhelp:

[patrickhorton]

What makes you think it is the EGR? I have the same car and can't see how this could happen. Are you talking about when the engine ticks over. Is it all the time? What do you call hunting - revs uneven?

I may have some suggestions if you have a bit more info.

Patrick

[Kleinxv]

Hi the cars starts idles over and runs normal. When the engine is stared after about 20 sec there is a metalic clicking noise it almost sounds like a bad micro V belt tensioner bearing or alternator bearing however when you increase the engine revs the noise does not increase linear to the RPM. The noise sounds to be coming from the black box on the EGR system/intake manifold I think it is the Potentiometer N18 if I hold my hand against said item I can feel like a relay or something similar pulsating inside this is in perfect time to the noise that is being emitted. I am wondering is there a flap of some type in the manifold housing that is damaged in some way and not performing correctly and the ECU is continually telling the EGR actuator to try and work but the desired results are not happening and so the cycles continues.

[patrickhorton]

There is an electric motor in the box on the inlet manifold that moves the EGR flap. If the flap sticks/gunks up, I've heard it can strip the gears in the motor or snap the flap off its shaft. I suggest you take the egr valve off and look at it. It will be gunked up, I guarantee but whether or not it has failed you will see.
There are some notes on removing the egr for cleaning if you search on the B7 forum.

Good luck

Patrick

[Kleinxv]

Thanks for the info the Gearbox inside the EGR electronic actuator assembly was full of an oily deposit I can only assume it leaked in past the EGR flap actuator shaft this in turn turned the nylon type gears to putty and lifted lumps out of them. The actual valve was not sticking but oh boy was it heavily sooted up. If the assembly is that badly sooted up surely the entire inlet tract right into the head must be the same? Can the EGR be taken out of service what would the consequences be if not after how many miles would the valve need to be removed and cleaned out again? :Blush:

[Adman]

Hi,

I have cleaned my EGR a couple of times now. You are correct, the inlet manifold can get quite sooted up. Others on here have had it quite badly sooted, mine wasn't too bad when i took it off to clean. Patrick has done a post where it tells you how to take the inlet manifold off and clean it - do a search. As for taking the EGR out of service, you can get a blanking plate that fits between the EGR and the EGR feeder pipe. Not sure what effect this has on performance though.

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[Redroco]

I have a A4 S-LINE QUATTRO SE B7 170 BRD ENGINE. 2007.
Same here, about 6 months ago it rattled its socks off, was told by my friend whom has his own garage, it was nick nacked. It cost me £200 for a new one and I fitted it myself in 5 mins, and a new throttle flap £200 nomore rattling.

Its also had the dreded yoyo temp guage reading, new thermostat fitted also new temp sensor.
New boost sensor on the turbo, as this was faulty aswell. That was becuase I was doing 70mph down the A1 and my engine speed went from 70 to 0 in no time.

I am now left with, my car hesitating at low speed between 1500-2000 revs in slow traffic, the feeling is fuel starvation then it goes normal. I had a Merc 200 sport Edition before this Audi, it had the same problem? I got rid as even Merc could not cure it. I will be keeping my Audi however its my 6th Audi. I have replaced the AMM and a new Air filter. I am determined to find and cure the problem myself. No fault codes showing to hint what it is, but its niggling me. Car is fantastic apart from that, picks up great at the top end, its only got the problem at low speeds. May have to live with it.

[Adman]

I am now left with, my car hesitating at low speed between 1500-2000 revs in slow traffic
I have the same, no idea what it is. plugged VCDS in and all injectors are fueling within spec so don't think its that. I have had this hesitation since owning the car but it has got worse recently. I noticed my software version is 9971 but others on here have said the latest is 9973. I phoned Audi to get it put on and they said 9971 is the latest software!

Sorry not much help but just passing on my experience with the 170!

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