Audi A4 1.9 tdi q, found a hose not connected to anything and tied up, egr vacuum hose?

[dcds4]

Please see pic, was under the bonnet today changing a bulb. Noticed there was a little hose that had been taken off and folded in half. Theres a hose connector where it used to be fitted to, think its on the egr valve. Car seems to drive fine, would say its slightly under powered but that may be due to the weight and transmission losses.. Our other car is an ibiza fr tdi.

Could anyone tell me why this would have been done? What difference it makes and do i need to repair this? The fitting under the part was a bit oily too, is this a problem? Car also takes quite a while to reach temperature, could this affect this?

Would really appreciate any info

Thanks

[sbt]

hi mate it would appear your anti shudder valve is missing . the tube should attach to a black plastic body containing the anti shudder valve . when the engine is switched off a vacuum is created which operates a rubber diaphram which pull an arm down this arm should be attached to the little steel arm sticking out of the side of the egr valve . when the arm opperates at engine shutdown it closes a butterfly flap in the egr valve therfore shutting of the air supply to the engine . have you noticed that when you turn the engine off the car shudders slightly . as regards the car being slow to warm up it will not be anything to do with this part , the fact its a diesel and its very cold at the moment is the reason your car is taking longer to warm up diesel are very thermally efficient compared to a petrol engine. hope this helps

[dcds4]

Yes it does shudder, also on startup. Is there a reason why someone would remove this part?

Thanks for your reply

[sbt]

i cant think of a reason to remove it . but what can happen is oil can leak from the egr valve which then runs down the operating arm and into the rubber diaphram causing the rubber to perish and break which then does not operate the arm this is exactly what happened to mine . the unfortunate thing is you can not just buy the diaphram pod it comes as part of a new egr valve i got mine of ebay audi wanted 189 quid plus vat

[dcds4]

i cant think of a reason to remove it . but what can happen is oil can leak from the egr valve which then runs down the operating arm and into the rubber diaphram causing the rubber to perish and break which then does not operate the arm this is exactly what happened to mine . the unfortunate thing is you can not just buy the diaphram pod it comes as part of a new egr valve i got mine of ebay audi wanted 189 quid plus vat

Would it do any harm if i didnt replace it?

[nevo]

Basically no,its there to give a more refined shutdown,and shut the air off in a runaway engine,but thats a remote situation,you need to lock it somehow in the fully open position,failing that I would search round the breakers for a secondhand one,just suck on it to be sure the diaphrams ok.

[sbt]

there is no need to lock it as it is in a permanant open position without the arm attached. there is what is known as a run away engine this is very very rare but what can happen is your engine can run on engine oil and rev to a point of self destruction if say for instance your turbo seals split . the chances of this happening are so unlikely that its not worth worrying about. but if it did happen the only way of stopping the engine is to stop the car and open the bonnet and flick the small steel arm that sticks out of the egr valve to the closed possition this will shut off the air supply and stop the engine