2009 3.0tdi lumpy idle.

[Mechcanico Lee]

Do you mean diss connecting the egr it carrys on cycling ,or diss connecting it the engine is still missfireing

[snapdragon]

When I had my misfire, the rod to the left of the green box would thrash back and forth at idle - it was random, not in a rythm, I put is down to explosions in the exhaust manifold.

[legacy4cam]

With the vacuum hose disconnected from the egr diaphragm, the uneven idle remains. The diaphragm stops cycling.
In answer to the earlier question, the swirl flap rods appear to be acting normally.

Any other suggestions welcomed.

[Mechcanico Lee]

The rod to the left side of green box is egr cooler switch over valve , when engines cold egr cooler is bypassed , when engine gets warm egr gasses go through cooler to reduce cylinder charge temp when egr is in use .

The air mass volume plays a big part in how much egr duty is deployed , so for instance if swirls are having funny spells , air mass volume can change and this will affect egr control duty .

Possibly aswell snap D where you say the linkage was flapping about randomly it could of been back pressure from manifold or it could of been ecm turning egr control and cooler bypass off randomly due to misfire detection , very often in missfireing situations some of the emission control will be turned off .....its part of limp strategy .
That's why I was asking op to check the swirl arms , it's hard really to give diag advice over a forum ....your relying on the poster to give as much info back as possible but without the car in front of you it's difficult .

Could still be injectors this one but with diesel missfires I like to rule out egr and swirls , I like the diag posts ......as you have probably noticed hehe brain testers

[Mechcanico Lee]

Originally Posted by legacy4cam

With the vacuum hose disconnected from the egr diaphragm, the uneven idle remains. The diaphragm stops cycling.
In answer to the earlier question, the swirl flap rods appear to be acting normally.

Any other suggestions welcomed.

Arrr right you are ..... more diag needed on the injectors mg /str .... do you use supermarket fuel or branded stuff by the way

[legacy4cam]

I tend to buy fuel from wherever I'm near, not brand loyal, and it'll get supermarket fuel occassion, but not solely. Too long in petrochemical site to get hung up on fuel "quality".
The swirl flaps do seem to be behaving as described above as normal.
VCDS to check injector flows is next.

[legacy4cam]

Car booked in to Argyll Diesels on Friday...I'll update the post after the car has been if they have any success tracking the fault. Fingers crossed!

[Mechcanico Lee]

Yes keep us informed of the findings

[legacy4cam]

It appears my car is suffering from an exhaust valve sticking open slightly leading to low compression at idle and hence the lumpy idle!

2009 car, Audi approved used in 2011 at 41k miles, now on 69k miles, serviced every 8-9k and driven in a moderate fashion, ie allowed to warm up, but given enough throttle on occasion to keep the dpf clear and exercise the turbo.

Disappointed to say the least!

However, it's only metal.

So I now need to know if anyone has undertaken a cylinder head removal with the engine in the car, and if there is a workshop manual in circulation that I can buy or download?

Any help greatly appreciated.

Iain

[legacy4cam]

Sorry...Just found manual in Tech Dump.....brain a bit out of sorts!