DPF light... (with new DPF)

[FD_VRS]

Morning all, 

 

Right,  I bought my 57' plate VRS estate about a month ago.  Since then I have had the DPF light on multiple times eventually resulting in a visit from the RAC on the shoulder of the M4. 

 

The car was recovered to the garage I purchased from and they have been great.  That visit back to them resulted in a fresh DPF due to Ash level.  It has also had the two sensor on the DPF replaced. 

 

So much to my surprise this week, the DPF light is back.  It cleared after a trip on the motorway but a couple of days later it's back again.... 

 

My gut feeling is glow plugs failing to create the right amount of heat to affectively regen.  

 

Am I wrong?  Any other theories guys? 

 

Taking the car back to garage tomorrow and they are taking it to a VAG specialist Monday. 

[Breezy_Pete]

Glow plugs aren't what create the heat for regens. Burning fuel is.

[FD_VRS]

Okay, great!

 

Just figured as the plugs cause the ignition of fuel it might be related as the car has been sluggish to start on occasions.

 

Cheers Wino. 

[Breezy_Pete]

There's probably some other sensor misbehaving. Let us know what the VAG specialist says, please.

Try to charge any necessary work back to the garage that sold it to you, as it seems like they knew the car had troubles.

[FD_VRS]

VRS update:

 

Are there any Skoda techs in?

 

The garage the car is with is currently "no further forward with it".  I don't have any more detail than that so how much time has been spent on the car is unknown so I am continuing my own troubleshooting without the car to hand but so far the following has been replaced prior to this visit back to the dealer.

• DPF Pressure Sensor
• Temp Sensor
• Lambda Sensor
• DPF

The light for DPF was still being triggered after these parts were fitted but not quite as bad as before, although I wouldn't expect the DPF light to come on a week after a new DPF.  Am I right?

 

Does anybody have any more ideas on what might be triggering the light?

 

Update:  Garage it is at are investigating EGR valve.

Edited 23 August, 2018 by FD_VRS

[Rustynuts]

Really need to know if the dpf is correctly reporting that it's in need of an active regen (full of soot), or if the systems are incorrectly reporting that the dpf is full. It could simply be that there's a combustion issue which is causing too much soot to be produced and is filling it over fast. Something like a boost leak would cause this possibly. May also be burning oil which again would upset the combustion and fill the dpf.

 

Best idea is simply tell the garage you want your money back. Sounds like both the car and them have issues.

[Felvo]

Couple of questions;

 

After the new dpf, has a dpf statistic reset been performed?

 

Is it a genuine dpf?

 

Are you providing the engine sufficient load to generate heat to burn the soot? Ie. regular stints on the motorways at a constant speed.

 

Was an oil change performed post dpf change with the correct oil?

 

Do you know the P code?

 

and finally.

 

Does your engine consume any oil?

Edited 25 August, 2018 by Felvo

[FD_VRS]

Hi Felvo.  Thank you. DPF was £600 so doubt it's genuine. I will ask about static reset.

 

My commute consists of 30 minutes on the M4 each way plus A roads. 

 

I would imagine so but I was going to do my own oil change anyway. 

 

When it failed before P2002 was triggered but no codes this time. 

 

I don't think it's consuming oil. 

 

 

Edited 26 August, 2018 by FD_VRS

[Felvo]

Few things spring to mind.

 

P2002 refers in the first instance to the exhaust pressure sensors A and/or B (or 1 & 2 depending on how you look at it.) One takes the pressure pre DPF the other one takes the pressure post DPF to determine the kpa at which air can flow through to determine when to do a burn. Or a pressure loss in the exhaust, the light more refers to an error in pressure in the catalytic converter "dpf" system. Cars these days won't do a predetermined distance before burn, it's all pressure related :(

 

I would;

- Double check that the wiring to the sensors A and B have not been compromised in the DPF swap, they are thin wires and a total bitch if they get in the way.

- Double check the sensors are both plugged in.. if they are home and clicked, you'll get a world of problems such as an intermittent dpf light lol.

- Get the sensors continuity tested with an amp meter, ensure that they are returning an appropriate voltage. Secondly with any OBD scan tool, it will show you the exhaust pressures that each sensor is returning with the engine running, if either show up error or 0.01 with an engine running, then replace it! If both seem to returning values that are relevant to your throttle position (ie. when you rev it the pressure gets higher) then move on.

- Check for leaks in the exhaust line. It is more likely to be pre dpf that a leak would throw P2002, Good hint is any diesel soot marks under the car surrounding the exhaust line as you follow it.

 

Make sure you do that DPF counter/statistic reset. Different cars call it different things, but in short they all return the DPF regen counter back to 0 and allow the ecu to calibrate ash, soot and pressure loadings.

 

Lastly, if you can find any hints that your car is actually doing a burn, that would be great, P2002 in it's final instance will show up if the car has exceeded 1000km/600miles since a previous burn. However, this is more likely to show the anger management (engine management) light as well.

 

Hope this provides a little insight for you.

 

[FD_VRS]

Thank you Felvo, really appreciated! 

 

That code was triggered pre DPF replacement and haven't seen it since. Fingers crossed. 

 

I recieved an extensive update from the garage this evening. 

 

The short version is, the DPF is after market but from a reputable source.  A full reset was performed along with a fresh oil change. 

 

They had been baffled as to why the DPF light came back and so soon.  The specialist that was looking at it for them was sharing figures with Auto Logic for added support, who were apparently also stumped. 

 

However, they think they have pinned it down to an air intake leak.  They now want to run the car for a bit to confirm the fix. 

 

So, potentially a glimmer of hope but short term I'm stuck with a Pug with an 'interesting,' biting point and first gear knack.... 

[Felvo]

1 minute ago, FD_VRS said:

Thank you Felvo, really appreciated! 

 

That code was triggered pre DPF replacement and haven't seen it since. Fingers crossed. 

 

I recieved an extensive update from the garage this evening. 

 

The short version is, the DPF is after market but from a reputable source.  A full reset was performed along with a fresh oil change. 

 

They had been baffled as to why the DPF light came back and so soon.  The specialist that was looking at it for them was sharing figures with Auto Logic for added support, who were apparently also stumped. 

 

However, they think they have pinned it down to an air intake leak.  They now want to run the car for a bit to confirm the fix. 

 

So, potentially a glimmer of hope but short term I'm stuck with a Pug with an 'interesting,' biting point and first gear knack.... 

 

A pug is better than nothing!!

 

I thought there might be a leak of some description, as soon as you start playing with an original exhaust system and the amount of gaskets and sealants they entail here’s a high probability something might go skewy.

 

My fingers are definitely crossed for you!

[FD_VRS]

It is indeed better than nothing and they didn't have to lend it so I am grateful.

 

Although I did at one point get offered my bosses mk7 Golf GTi... Should have jumped on that offer in hindsight. 

 

Thank you again for your input.  Will keep this updated. 

[FD_VRS]

Right, the car has been on a 130 mile round trip on a mixture of roads in and out of traffic.  No issues, no warning lights.

 

No attempts or failed regen, DPF pressure was check and it's 0 at idle.  Is this normal or should it be registering something?

[Felvo]

9 hours ago, FD_VRS said:

Right, the car has been on a 130 mile round trip on a mixture of roads in and out of traffic.  No issues, no warning lights.

 

No attempts or failed regen, DPF pressure was check and it's 0 at idle.  Is this normal or should it be registering something?

 

It should register low numbers at idle and when you rev it, it should go up with the amount of air passing through the exhaust.

[FD_VRS]

Had it confirmed the numbers and low and normal.  The car seems good now.  

 

I do have proof the car is running well!!  The guy who took it for a long test drive got caught out doing 80 on a bypass by a mobile camera unit.  I got a surprise letter on the mat Saturday morning from their local constabulary that led to an entertaining call to the garage. . . 

Edited 3 September, 2018 by FD_VRS

[FD_VRS]

Evening all,

 

I am happy to report the VRS is back in my possession and running great.  A noticeable improvement, fingers crossed for plain sailing!