VW golf mk5 gt tdi dsg 170bhp 57 plate engine BMN - EGR fault

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Mon 1 Jun 2015 15:42
VW golf mk5 gt tdi dsg 170bhp 57 plate engine BMN - EGR fault - Paulgoober

Hi

I have a issue with the egr first the the battery went flat since then the warning light came on fault code PO404 which will clear, I got a second hand egr replacement which was tested and worked but still the same issue i have read so many posts on the subject until it gave me headache. I work away and travel 90 miles on the motorways i normaly get 52 mpg now its more like 46 mpg friday last week 57.2 mpg ? Do any of you guys know what parts are the main offender for this fault I have ordered a solenoid today. Also a chap i know says he can remap the ecu and turn off the EGR plus give the car a bit more BHP and MPG but i have some worries regarding the DSG box.

Really dont know what to do dont mind spending but could replacing every part. Thanks for any advive on the matter regards Paul

Reply | Report as offensive | Link
Mon 1 Jun 2015 23:44
VW golf mk5 gt tdi dsg 170bhp 57 plate engine BMN - EGR fault - Railroad.
The EGR system serves one purpose and one only. It's part of the emission control and helps to reduce levels of Nitrogen Oxide (NOx) by allowing some exhaust gas back into the air intake which in turn consumes oxygen and reduces combustion temperature.

The EGR valve simply opens and closes to allow exhaust gas back into the air intake or not. It does not perform any other magic function. The valve should always be closed at engine idle and full load, and only open under cruise conditions. The driver therefore should not notice when it's open.

The operation of the EGR valve is monitored by the ECM via the Mass Air Flow sensor. Less air will pass through the sensor when the EGR valve is open, and more when it's closed. If this reduction in air flow is not detected when the ECM commands the EGR valve to open the ECM will reduce engine power so to control NOx emissions. This is not always recognised by a fault code as the MAF may stay within its programmed parameters.

An unfortunate side effect of EGR is the very common build up of thick gunge inside the air intake. This is a mixture of exhaust gas and oil residue. This will restrict air flow and it is advisable once in a while that the manifold be removed and thoroughly cleaned.
Reply | Report as offensive | Link
Tue 2 Jun 2015 19:57
VW golf mk5 gt tdi dsg 170bhp 57 plate engine BMN - EGR fault - Paulgoober
Thanks for the info ,I have had the car checked with vcds the error code is now p3130
Does this information point me to a part Thanks Paul
1 Fault Found:
012592 - EGR System
P3130 - 006 - Regulation Range Exceeded - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100001
Fault Priority: 1
Fault Frequency: 3
Reset counter: 40
Mileage: 108671 km
Time Indication: 0
Date: 2000.00.00
Time: 14:05:38

Freeze Frame:
RPM: 800 /min
Torque: 40.0 Nm
Speed: 0.0 km/h
84.63 %
Load: 85.1 %
Lambda: 0.0 %
Battery Volts: 1.0 V

Readiness:
Reply | Report as offensive | Link
Wed 3 Jun 2015 09:54
VW golf mk5 gt tdi dsg 170bhp 57 plate engine BMN - EGR fault - Railroad.
I would make a couple of suggestions. The fault code description says regulation range exceeded, and it would seem by the freeze frame data that the fault occurred while the engine was idling. This leads me to suspect that the EGR valve failed to close fully, or was prevented from closing fully which it should at idle. It could be sticking with carbon, or if it's electronically operated it could be faulty. This has happened before on these engines. Remove the EGR valve and check its operation with VCDS, and also give it a thorough clean. Whilst it's off check inside the manifold for carbon sludge build up, and if there seems to be a lot I'd consider removing it for cleaning too.
Reply | Report as offensive | Link

From which small car to buy at which price point to the best UK-built cars, our Top 10s have the lot. Click now for your shortlist.

Unsure of what to buy? Our Top 10s are here to help you....