EGR Valve Cleaning Guide

**motionpotion** · 06-09-2013,08:22 PM

My 2006 A6 Allroad quattro seems to be getting laggy in 3, 4, 5th gears in that the kickdown doesn't kick like it used to.
I'm thinking about having a go at cleaning the EGR valve it this weekend to see if that improves the choked up feeling.

Does anyone have a video or set of photos to guide me while doing this procedure?

**Guest 2** · 06-09-2013,09:19 PM

Jim cleaned his on his 2.0 TDI - I can't see it being too much different although location may differ from the 2.0

A6 EGR location & removal "how to?" - Page 2

**gupsterg** · 06-09-2013,10:15 PM

On the V6 it's a mare vs the 2.0 TDi and don't I know it

...

**gupsterg** · 07-09-2013,09:33 AM

Why is the EGR valve a mare on the V6 vs the 4 cylinder TDi?

Well the access is nice and easy on the 4 cyl. TDi, the EGR valve is located on the right of the engine and not sitting smack bang in the middle, surrounded by a plethora of engine parts.

Even the EGR cooler is nice and easy access on the 4 cyl. TDi, it sits on the left of the engine. Where as the EGR cooler is located smack bang again in the V of the engine on the V6. All the bolts holding the EGR cooler to the EGR cooling flap unit are inaccessible without removing the complete EGR cooler & flap unit out together.

Then you've also got coolant running through the cooler and cooling flap.

In this post is a diagram that Crasher placed Link:- EGR Valve

Hoses 8 & 11 are the main coolant pipes to EGR cooler, then 12 goes to cooling flap unit 21 IIRC goes off to the oil cooler.

From this post Link:- Audi A6 2.7 & 3.0 TDi EGR & Intake system cleaning info please...

Above is the flow of the EGR gas, the red line is the throttle body adapter, the yellow diamond is roughly the location of the EGR inlet port into charge air system. Yellow line is the EGR gas flow, blue lines when going through EGR cooler.

You may wish to prepare yourself for a lot more work. You may find your throttle body adapter needs cleaning. I know of 3-4 VWAF members which have done it and on other forums.

To get at EGR valve bolts IMO the minimum you'll need to take off is the black top intake pipe, I also had to remove the metal high pressure fuel lines connecting left and right rail to each other and to the high pressure fuel pump. The EGR valve and the connecting pipe will come out together as the bolts 31 are inaccessible. You may need to take out the lower manifolds to remove the whole EGR system as one piece like below.

Now lets say if you get your engine to the stage in below photo and EGR cooler is blocked and you haven't drained coolant you could potentially end up with a leak going into the cylinder head via the inlet valve bores. Also ref below image and the earlier one of my engine and note how much stuff has been removed.

IMO the 2.0 TDi is a doodle vs the V6 TDi ...

The 2nd hand EGR cooler + cooling flap I bought the bolts 3 & 18 from diagram had been snapped off, even my bolts 3 are corroded. I have bought new ones to fit when I do work on mine but don't know if they will snap.

I can not stress enough how preparation is key to work on the V6 without causing issues from meddling with the EGR IMO.

Please read the linked threads.

**motionpotion** · 07-09-2013,06:46 PM

Woah. This is way beyond my abilities. I underestimated how complex this is compared to other cars I have owned that I have cleaned the EGR valve on. Thanks for the details and links gupsterg. Very much appreciated.

**gupsterg** · 07-09-2013,07:08 PM

No worries mate

, at least you understand process and when a mechanic say it's gonna cost x you can make a informed decision.

The cooling flap unit I can't see blocking but only the vacuum element failing (item 15). Since owning my car and being glued to forum only seen one post where cooling flap has fault and that was movement on butterfly axis.

The EGR valve I can see clogging i) where it open on cooling flap side ii) coking on the opposite side of opening opening iii) vacuum element having fault.

The EGR cooler I can see clogging with soot.

I also believe due to how EGR inlet port is on throttle body it's susceptible to clogging. The EGR gas flows up and out of port thus the lower section of port is like a catch can for the soot, I will add photo at some time of design.

I would check EGR MVB's and AIR MASS readings before deciding to get work done.

**andysimmons7809** · 08-09-2013,03:27 PM

Took the EGR valve off of my 2.0 tdi 170 A4 Quattro today to clean. Yes it was extremely dirty but I found that the actuating shaft controling the valve had snapped. Possibly worth considering a regular removal and clean every now and then as opposed to £190 replacement sourced through GSF. Not a difficult job, minimal tools and a little bit of knowledge to complete job in two hours.

**gupsterg** · 08-09-2013,03:36 PM

Thank you for your share, thread is about motion potion having an A6 Allroad with 2.7 TDI total different setup.

Your EGR valve is electronic, the one on the 2.7 TDi or 2004 -2009 V6 TDi is not. It is not the same design. It is vacuum operated, it can stick due to coking, the vacuum element can start leaking, also read they can get stiff and start seizing.

But agree regular cleaning would be good idea and keep things in better shape, I'm even considering EGR delete so don't have to worry about cleaning and associated issues.

**andysimmons7809** · 08-09-2013,04:18 PM

If you have not already done it, I would also consider having your DPF removed. Mine was forever trying to regenerate and the fuel consumption was awful. Best £500 I ever spent and I now average mid 40's mpg

... and I don't hang around. I have even seen 55mpg on a long motorway journey, not bad for a 170 quattro!