TDI Woes - DPF and Coil warning lights

[Andoni]

Hi all,

This is my first post on the forum, I'm hoping someone can provide any information, so here goes.

We have a Golf Mk6 S 1.6 TDi 105PS, and have had it since Dec 2009. It's done about 8,000 miles.

From the first few months of delivery, the DPF light came on, but after a 'vigorous' drive on the motorway it cleared the problem. When the light is on the idle is lumpy and the car vibrates ever so slightly, which I take to mean that the carbon deposits are blocking something in the exhaust and the engine management gets confused? Apologies, I'm not 100% au fait with diesel engines and the way they operate (mk1 GTi and ex-mk4 anniversary gti owner here).

Last weekend the light came on again, and after a while, the coil light started flashing. There was no turbo response and it seemed like it was in some sort of limp-home mode. Then the engine management light came on.

I haven't driven it since this came on, and have booked it in to be looked at tomorrow. Is there a problem with the coils on the TDI? I am hoping that it's a simple fix, and covered under warranty.

If anybody could shed any light on what this could be it would be most appreciated.

Thanks

Andoni

[dubber36]

The "coil" light is the glow plug warning light. When this flashes, it could mean a multitude of things. Anything from a faulty glow plug to a brake light switch problem.

From what you have said, and the very low mileage that the car has done, my money would be on problems with the DPF. Your spirited drive may have done a temporary fix, but the car gone into limp mode would suggest that it is bloked. There are gas pressure sensors on either side of it and if the values differ too much, the car will go into limp mode.

The first step would be to take it to the dealers for them to carry out a forced regeneration of the DPF. It is to hoped that this will do the trick, otherwise you will probably need a new DPF. You may struggle to claim this under warranty as VW suggest that cars with DPFs are not best suited for mainly short journeys due to this very problem.

Good luck and keep us posted.

[Andoni]

Thanks for the info.

I'll let you know what VW say.

After this all happened I read in the manual about driving short journeys. If that was the case there would be no point in having a diesel in London? Should have got a TSI 

My issue with this is that it started within a few months of getting the car. Is there a specific type of diesel I should be using? 'Low Sulpur' says the manual, which company would do this? I don't mind sticking to one particular company.

[The Doc]

UK diesel is ultra low sulphur, Best advice is once it's been fixed if the light comes on take it for a drive on the motorway - they are a pain in the ass 

[Andoni]

I have done every time it's happened.

The manual says if it comes on, drive in 4th at speed and it will clear the filter (or something like that).

The DPF light has come on about 7 or 8 times in a year. Remind me never to get a TDI again 

[Andoni]

OK so they called me back and the did the following-

1. regenerated the DPF or something
2. performed a software update on the ECU

the second point is particularly disturbing. if they have any kind of update there should be a communications channel to all buyers telling them to bring their cars in for an update or do it on the next service...

[dubber36]

The software upgrade will give you a reduced power map that is designed to preserve the DPF. This was carried out to many early PD 170 TDI's without the owners even being told about it. In the case of the 170's it reduced the power by around 20bhp.

I don't think you will see losses as high as that with your engine. In fact, if you mainly drive around town, you probably won't even notice the difference at all, but ultimately you will have less power than before.

[Rhyso]

The software upgrade will give you a reduced power map that is designed to preserve the DPF. This was carried out to many early PD 170 TDI's without the owners even being told about it. In the case of the 170's it reduced the power by around 20bhp.

I don't think you will see losses as high as that with your engine. In fact, if you mainly drive around town, you probably won't even notice the difference at all, but ultimately you will have less power than before.

Has anyone ever had this confirmed on a rolling road?  From what I've read the update reduced power in 1st and 2nd gear and upped the regeneration cycles of the DPF 

[The Doc]

I'm glad it's sorted for you, be carful as once it's really blocked you'll have to pay vw £££ or pay someone like me lots of your hard earned to swap your DPF for a by pass pipe and a load of resistors (resistors not normally required normally but you can't map the ecu in the 1.6 yet)

I've not seen one on the dyno with reduced power output in 3rd / 4th but I've not tested in 1st / 2nd, but I will if the fecker will stay on the dyno 

[JC]

but I've not tested in 1st / 2nd, but I will if the fecker will stay on the dyno 

you need ballast for that 

 let me know when your need me