Golf BMN 170 cutting out

[NathanG]

Hi all, sorry that this is my 1st post and its about my Golf but i also have an A3 with similar problems, same engine (BMN) same year 57. Im at my wits end as both the cars are just too unreliable to even use, i have to borrow my sisters car all the time.

Main issues right now is the golf. After driving for aprox 10-12 miles the car has a melt down out of nowhere in 4th at 70mph, feels like it down on power and only 3 cylinders. If I dip the clutch the car just cuts out, no warning lights before or after the event either. When i lift my foot back up at put the car in 6th it drives absolutely fine again, if i put it back into 4th it does the same AGAIN. If its having a funny 5 minutes and running badly and i dont dip the clutch while moving it will stall at a junction/roundabout and it WILL NOT restart at all. You can literally crank it solid for a minute and nothing.

I’m at an utter loss. In the last week i removed the EGR, throttle body and inlet manifold, all were so sooted up none of the parts could move. They’ve now all been cleaned and refitted. The EGR cooler was replaced with a new part as that was beyond help. Car runs well around town but im just too scared to drive it more than 10 continues miles and im sick of calling the RAC to recover me for the same thing again. Ive called them 3 times now. Ive also replaced the fuel pump as that was an issues.

i would really really appreciate any help or suggestions. I dont have VCDS codes either atm but im working on it.

 

[LEE69]

Turbo veins gunked up with soot?

 

[NathanG]

Nope, checked those while i had everything off. She boosts well in all gears no problem what so ever, just after 10-12 miles so wont boost properly in 3rd and 4th. Cant comment on 5th and 6th as she wont rev above 3k when it starts and i need to jeep the power down or risk getting stranded on a junction or roundabout.

 

[NathanG]

Turbo veins gunked up with soot?

actually i didn't check the veins, i just checked for play in the shaft. Surely it wouldnt boost at all if the veins were All sooted up.

i was considering that it may be trying to do a regen but cant because the DPF is blocked and cant deal with the increase in pressure so want to stop running so hard but surley id have a DPF light on or coil light. Car is in 144k and 57 plate. I only run the car on Texaco fuel. If i put supermarket fuel in the car with 3 miles i get a DPF light.

 

[Daveyonthemove]

Did the RAC run a diagnostics check? If so, what fault codes did they find?
If you think it's a DPF issue you could try putting an additive in to burn off the soot, but it may be past that by now.
Out of interest, what sort of daily mileage do you do with it (when it runs properly)?

 

[NathanG]

They’ve only ran diagnostics once on it and it came up with fuel pump, so I replaced that And it was fine for 2 days but then started doing the exact same thing again. SWMBO has been using it as the A3 is too unreliable. Ive driven it for a year with no problems 60mile round trip a day to work on motoways. Since she’s had it since January she’s done Jan-March 60 mile round trip a day. March until now all its done is little trips of a couple of miles at best.

As far as DPF cleaner goes i put some in the tank yesterday before taking it out to try to get it to do a regen.

 

[Daveyonthemove]

When was the fuel filter last changed?

 

[NathanG]

About 4 days ago, genuine VAG part. Ive just taken the DFP out and smashed out the internals (mega black as well) Will be having it mapped out the morning.

 

[NathanG]

Just thought id do a bit of an update. After taking the DPF off the car, removing the internals, welding back up, refitting and having the DPF, EGR and associated sensors mapped out the difference in the car is like night and day. The car has never ticked over so well, really smooth, sounds a lot better and is a lot less smokey whilst under load and on tick over.

 

[NathanG]

Just thought id put a pic up of the EGR for reference (and comedy value).