A4 B7 Loads of black smoke, no power then wont start - FIXED - EGR valve

[Mikeybs]

Audi A4 B7 Avant 2.0 tdi S Line

Quite a common thread over the years and loads has been written but none really helped me when this happened. Thought I'd post my fix in the hope that someone else gets a quicker fix than I did.

Symptoms: A little bit of misfiring occasionally and not much throttle response at high revs. This became gradually worse but seemed a bit intermittent. It was a wet day so put it down to some sensor getting water ingress. Anyhow, on this occasion it suddenly started belching clouds of black smoke and loss all power. had to slip the clutch like crazy to get across a roundabout to a place of safety and when I eventually stopped it would start again. All I got was very rough running up to about 800 rpm and loads of black out the back end then it cut out after about 5 secs. No real response to the throttle at all.

AA man was flummoxed. Checked the EGR (Exhaust Gas Re-circulation) valve to intercooler hose for leaks and connection. All was good. Left it disconnected and made no difference. Unplugged the Mass Air Flow sensor, no real change. Checked all the hoses and pipes around the inlet manifold, turbo, EGR valve etc and all seemed to be right. When trying to start it a lot of smoke was backing up out of the EGR where the fat intercooler hose should have been connected. He suspected I had a blocked Diesel Particulate Filter (DPF ...I hate it when people post loads of acronyms supposing that everyone knows what they mean) ...any way long story short, I got recovered home and pulled the inlet side apart the next day.

(cross reference image numbers and figures in brackets below)

Removed the Intercooler hose (prise up the stainless wire clip then wiggle off the hose)
Disconnected the 2 electrical connectors under the EGR valve and Anti-shudder valve (the crap kind that you have to squeeze and pull at the same time)
Disconnected the 10mm bracket bolt to allow a bit of movement on the black coolant pipe (1)
Removed the 2 allen bolts on the EGR to exhaust pipe (2)
Removed the 3 torx bolts on the Anti shudder valve (3)
Removed the 4 allen bolts on the EGR valve (4)

I also removed the inlet manifold to clean it out. Most of the bolts are easy to see and access but there is a hidden allen bolt INSIDE the chamber at the top. It will be buried under a load of soot that will need to be scraped out.
2017-09-07_16-49-03.jpg

With everything off and cleaned I found that the EGR valve was at fault. There is a rod that rotates along its shaft to allow the metal valve to open and close where it meets the EGR to Exhaust pipe (2)
On mine the valve had broken clean off (see photo below).

2017-09-07_17-24-22.jpg

I ordered a brand new OEM VDO Siemens EGR valve for £117 (pays to shop around - World Car Parts ...great service Genuine VDO EGR Valve for Audi A4, A6 2.0 TDI) and in the meantime I cleaned all the bits that were going back on with carb cleaner once I had scrapped off the large deposits.

Fingers crossed I installed the parts in reverse order (no mean feat) and fired it up. Once the diesel deposits in the system had worked their way out it ran like a dream with no smoke at all. JOB DONE.

Hope this helps someone.

[sbukamzo]

Hi buddy thanks for sharing, mine was doing exactly like yours, I striped the EGR valve, it was broken also, I will order a new one today