TDI 170 Rough engine shutdown - At my wits end!

[max69vk]

For the last few months I've had a slightly annoying 'rough' shutdown when I turn off the engine.

Initially I was convinced I had an issue with a leaking EGR valve as the engine seemed to shut down a lot smoother when the engine was turned off during a regen, however after fitting a new ASV & EGR + gaskets the problem remains. After testing with VCDS the EGR & ASV appear to be operating correctly but the rough shutdown persists.

I've tried doing the sequential output tests & all solenoids & valves work ok, however when I do the ASV test the valve slams shut as it should (I've physically got my fingers in there to check it with the boost pipe off) but the engine still coughs & splutters on for a bit before shutting off (extremely roughly).

Now I'm left wondering where do I go from here? What is left to check? Is it worth removing the inlet manifold? I've found no evidence of it leaking, although my MPG has been utter sh*t recently & my DPF regens have got a bit out of hand of late although this could be a dodgy sensor. The only recent changes to the car have been a new air filter & a new battery after it died overnight, so I'm totally stumped as what is going on

 

[S3 TDI]

Does it feel like it's suffocating when you turn off the engine ? Also does the whole car shake violently ? From your symptoms above it sounds like an ASV problem but you've replaced that . How long does it take to switch off completely once you cut the ignition.

 

[max69vk]

When switched off from the key the engine shuts down pretty much immediately but it's rough. When shutting the valve with VCDS it's like it's choking & spluttering before dying. Strangely it's improves slightly if the engine is shutdown mid-regen which is what made us think it was the EGR leaking as this it totally shut during a regen (our thinking was that its wasn't 100% closing during normal operation)... This proved not to be correct after we swapped the part out

 

[max69vk]

Well, had a really good poke around today & noticed what looks like some oily sooty soiling down beside the left hand side of the inlet manifold where the swirl flap actuator connects, chances are this is what's causing the problem as the rubber seal is known to break down & leak. The worst thing is the part (a £2 rubber seal) is not replaceable so the whole inlet will have to be changed at a discounted cost of £541.33! It should be over £600! For a bit of ****** plastic!

Anyway I'm on the lookout for a 2nd hand manifold if anyone knows where to find one, even if the seal is knackered I'll modify the manifold to fix the issue.

 

[AdamS38P]

I have the seal you need mate. Pm me I will post to you.

 

[max69vk]

PM'd

 

[max69vk]

Not mine, but here's a video of a really badly affected inlet manifold. Im wondering if the repair kit for the 2.7 & 3.0 tdi would fit as they are readily available online...

 

[max69vk]

Still no closer to getting this fixed yet, been on the lookout for a 2nd hand manifold to modify (I'd rather prep one & do a straight swap than leave the car in bits) but despite contacting various places still no joy.

Can anyone recommend a decent breakers or parts place as I've tried but they only seen to have the alloy non-swirl variants in stock & the other option of paying over £500 to replace it because of a £2 part sickens me to the stomach.

 

[Rhyso]

I've got a manifold sat in the shed as the same thing happened to me

Not sure what variant I have but I can take a look for you?

 

[max69vk]

If it's the plastic one I'll buy it regardless of variant. If I can work out a retrofit repair kit it may be worth producing a few to help others in the same situation.

 

[Rhyso]

Replied to your PM with some pics

 

[max69vk]

Cheers Rhys