Hi all,

 

I have the EGR valve insufficient air flow fault on my 2005 54 plate Octavia.

 

My brother and I, him being the more mechanically minded, have cleaned the EGR valve thoroughly and checked the small pipe that connects to it to make sure it has vacuum. It does. Following the pipes back to you vacuum unit. Could the vacuum unit it be faulty? Or, we have had a possible answer via another forum. Could it be the Tandom Pump? 

 

We've cleared the fault a few times and it lasts for about 60 miles before the EML comes back on.

 

We changed the Mass Air flow Sensor with the connecting hose as that had a hole in it. Cleared the fault again and it lasted about 400 yards before the EML came back on.

 

It is so frustrating when money is tight and I'm just hoping someone can give me advise and help me with steps forward to getting it solved.

 

Thanks for reading this post and look forward to any replies.

What engine does it have?

It's probably the EGR valve itself. The diaphragm eventually perishes allowing the vacuum to leak causing an uncommanded closure of the valve and your fault code.

As above probably the egr doesnt hold a vacuum so it is remaining closed, you can test it with a hand vacuum pump to see if it opens but at around £50 for a new egr they are not expensive.

You seem to rule out vacuum solenoid module as you say you are getting vacuum on the pipes.

The EGR Valve is only a couple of years old. I paid £90 for it as its an Audi part. I was warned not to purchase the cheaper EGRs which were £50-55 as the quality/mould etc were not guaranteed to be right.

 

The engine is the 2.0 tdi pd 140 bhp.

 

I appreciate the replies, so thank you.

Hi Wiilydog

 

I was just wondering that the vacuum i was getting wasn't strong enough to open the valve - thinking that the vacuum solenoid module could be at fault.

 

About a month ago, the EML cleared itself which surprised me, for about 50 miles, then came back on.

if you have eliminated the EGR valve not being faulty, the next step would be the check the rubber pipes connecting up the EGR for any leaks.

 

a new vacuum solenoid cost around £200 new but you can get used ones from around £20 upwards from ebay - just avoid the ones that have signs of oil leaks around the connectors.   Here is an example what one looks like.

 

http://www.ebay.co.uk/itm/VW-GOLF-Mk5-AUDI-A3-2-0-TDI-16V-QUATTRO-VACUUM-SOLENOID-VALVE-BLOCK-6Q0906625E-/112208608206?hash=item1a20277bce:g:rAsAAOSw4HVWEkwx

 

 

I've replaced mine with a £20 one from ebay as it was make a sucking noise on switching off the engine

Also worth checking if the EGR cooler isn't all blocked with skuzz, as this can case real issues in the flow.

 

It's a right pig to get at though, as it's on the back of the engine.

I paid £90 for it as its an Audi part. 

 

Doesn't mean anything....Audi don't make EGR valves....it'll be a genune VAG EGR valve that would have been the same part had you bought it at a Skoda dealer. 

 

The actual EGR valve and it's vacuum pipework are the weakest links in the chain and should be definitively ruled out before throwing money at other parts. 

The EGR Valve is only a couple of years old. I paid £90 for it as its an Audi part. I was warned not to purchase the cheaper EGRs which were £50-55 as the quality/mould etc were not guaranteed to be right.

 

The engine is the 2.0 tdi pd 140 bhp.

 

I appreciate the replies, so thank you.

The 20ltr engine relies on the antishudder valve to make the EGR work. That's the butterfly valve directly underneath the EGR valve at the front of the engine, not the rear.... When you turn the key off to shut down the engine the antishudder valve closes to stall the engine by stopping the airflow. Its secondary function is that when EGR is operated, the antishudder valve part closes to form a vacuum in the EGR system and force the exhaust gas through the EGR valve. If you have insufficient EGR flow then its possible the antishudder valve is stuck and not closing. Check this manually, and also check there's no faults with the aircon system as the fuse for the rad fans is the same one.

Edited 13 December, 20169 yr by Rustynuts