Bloody stupid DPF :(

[Chrispy]

Well, there was me hoping the CR was immune from the DPF freaking out or doing anything stupid. Wrong. :(

Yesterday got in the car and started it up - all seemed fine until I set off at which point the DPF light came on. It's never come on before, regens have always happened and I've let them. Working 32 miles away too down the M62, A1 and A64 doing lots of good journeys has never been a problem. So a bit bemused I thought I'd add a detour onto my journey via the M62 to help it along with the regen I thought it was after. But after 20 miles of sitting in 5th at 70mph it was still lit. Hmmm. So I got to my destinaton and stopped the car, but curious I started it up again and after setting off once more it began what I thought was a normal regen process, raised idle speed, lumpy and masses of heat coming from the tailpipes. Fine I thought, you need more regen - so I let it idle there for 10 mins or so, heat wafting out from under the car. The idle speed then dropped back to normal and the car was fine for the rest of the day. Nice one, or so I thought.

Got in it this morning to go to Scarborough (a 78 mile journey) and just after setting off the DPF light came back on. Grrr. So I left it on and drove the car down the motorway and onto the A roads for a good 40 miles but the damn thing wouldn't go out. Pulled over at a parking lay by and the idle was stupidly high - around 1200 rpm whereas a normal regen without the warning light is about 1000rpm. So I set off again thinking perhaps it still wasn't enough (surely not) but about another 10 miles down the road the glow plug light started flashing at me, forcing me to pull over again. I stopped in a pub car park and quickly did some searching on here via my phone. Lots of mention of pressure sensor failure, MAF failure etc etc but nothing truly definitive so I thought enough is enough and set off back home classing the day out as a failure. No sooner had I got back onto the main road though to find it had gone into limp mode and I had nack all power. Even more miffed / worried I gently started to nurse the car home, only to find that after a quick prod of the throttle the glow plug light stopped flashing and the power was back, well most of it - it never feels quite the same whilst it's on regen, flat and lumpy. Then after about another 20 miles and back on the m'way the DPF light also went out. Marvellous I thought, until I got home and came to a stop just to find the idle speed still high and heat still belching from the exhaust. Also my fuel economy over the whole journey must have been in the early 20's it was that poor.

So yet again I left it to idle on the driveway for ages to allow the heat to build and hopefully burn anything off and after about 15 mins the idle dropped to normal again. Great I thought (again) so I set off round the block to make sure it was happy but no sooner had I applied load to the engine and came to a halt again that I found the idle speed had gone back to regen levels. Arrrghh. A several mile trip round the block at 50 mph in 3rd gear made no difference so I have up and we went out in the Fabia - the car with over twice the mileage and no such faults. :(

So, my question is - is this the pressure sensor that's gone and telling the car to constantly regen even though it might not need to? Off to the dealer (yet again) to get them to take a looky tomorrow but was wondering if anyone else has had similar issues and what the outcome was?

Cheers,

Chris.

P.S. I knew I should've got a petrol. :(

[jrw]

It does look like a fault with the system rather than the engine/fuel blocking up the DPF. Whatever the fault is confusing it into thinking it needs a regen.

When it went into limp mode you should have called Skoda Assistance (I presume that you still have it being a 2008 car) and get them to do a roadside diag to see what the fault was and get them to tow it to a garage to avoid any damage - also the added advantage you would have got a hire car!

Hope the car is still under warranty though!

[Chrispy]

Just come off the phone to Skoda Assist and have a dedicated technician coming out at 8:30 tomorrow to have a look.

Found a good post on here praising them and suggesting they carry spare pressure sensors on board too.

Before that I tried taking it out agaion to do a regen but it went straight into limp mode and all 3 lights were lit this time including the CEL which has not come on before. Car is still under warranty though - expires in November this year. I'm thinking it's the G450 sensor myself as it seems utterly confused about whether do do a regen or not. Either that or it is utterly clogged and needs a proper cycle to clear it? Hope the DPF itself is not kaput..... if so it'll be getting fixed then chopped in for a petrol. Stupid stupid idea the DPF - immature yet expensive and compulsory tech that ruins what is otherwise a good car.

[silver1011]

Don't be too hasty, it might not be the DPF, just a duff sensor.

I'd be more worried about the repeated attempts at forcing a regen, you may have done more damage than good.

Best just to leave it and wait for the Skoda technician to offer his verdict, hopefully a quick fix and all covered under waranty.

[Paul007]

The symptoms sound like a duff exhaust pressure sensor to me as you raise all the same issues I had with mine. Fixed under warranty without question and it never packed up again.

[Fester1698]

same for me this weekend and gonna get mine back in as the exhaust light has now come on its own

[bond007]

i didnt think the car could re-gen whilst idling i thought it had to be driven at a constant speed?

Edited 6 June, 2011 by bond007

[Nobafett]

Sounds very similar to the issue I had with my old PD vRS. I had the faulty sensor and a completely full DPF. Luckily was all sorted under warranty. Car was then traded in for the petrol and I haven't looked back since.

[jawsnpaws]

Just as an aside , living with Mercs and Skodas over the past 10 years , invariably , any problems that we have suffered , have largely been put down to failures of the monitoring systems rather than the car systems themselves !

Steve W

[Lou_O]

My CR vRS had a new DPF, under warranty, earlier in the year.

The reason given by Skoda was that the EGR vallve was clogged leading to excessive soot going to the DPF.

CR engines are not immune to DPF faults.

Edited 6 June, 2011 by Lou_O

[Chrispy]

Ok guys, all fixed now.

Had Skoda assist come out and they sent a dedicated technician - the one in the silver van. Brilliant chap, knew his stuff and also had a replacement pressure sensor on board too.

Mine had the old US model fitted which are the ones prone to failure from what I've read on here and it was reading the DPF as 100% clogged regardless of what he tried to do.

So he replaced the sensor with the new model and forced a regen as we went down the M62, sat bang on 2000rpm in 6th (just over 70mph) to keep the regen going whilst he watched the numbers drop from 24g down to 0g. About 10 miles down the road all was well.

So moral of the story is, chances are it's the sensor that's knackered and the RAC Skoda Assist technicians are brilliant.

Will post up a pic of the sensor - if it says "Made in US" on it then you have the old one and I would consider replacement as a matter of course. What can happen is if it fails the DPF can actually fully clog and then it could fail too. For the sake of a £50 part, well worth doing as a matter of course as VAG were still fitting the duff part in late 2008 by the looks of things as mine had it.

[jrw]

VAG assist are great as long as you get a proper VAG assist van and mechanic come out! My dad had an RAC man come out when his coil packs went on his Polo. He didn't have a clue. They recovered him home and a proper VAG tech come out the next morning and diag'd and fixed it in about 5 mins! The VAG techs also have a multitude of spares on board.

Saved on labour costs of taking it to a garage and most of the time they don't bother charging you for the parts! (My dad had all 4 replaced by him and was only charged for one!)

Anyway - Result

[Chrispy]

This is the offending part on the CR. Think it's in a different place on the PD. Look at the country of manufacture - the old one said made in the US. The new one says made in Malaysia.

Old one = bad, new one = good.

Just as well it went into limp mode as that stops the regen from happening, as the sensor was insisting it was still clogged so it would have regen'd forever and more than likely knackered the DPF. :(

[Lou_O]

Result!

To help anyone else who comes across this thread via google or whatever, could you post up the old and new part numbers?

Edited 6 June, 2011 by Lou_O

[Chrispy]

New part no is:

076 906 051A

[bond007]

i've done a couple for some of the members on here seem to sort they're problems out, the dedicated patrols are specially VAG trained and we stock they're vans with all the common failure items ie coil packs, dpf sensors etc

[jrw]

Will have to check mine later - didn't realise it was in such an obvious place.

[Chrispy]

Will have to check mine later - didn't realise it was in such an obvious place.

Me too

Couldn't believe the offending part is right in front of you when you open the bonnet. But looking at the location though it's vulnerable to water ingress as if you open the bonnet whilst wet then water could run onto it, or if you accidentally spray water when filling the washer bottle/ topping up the coolant it could get wet. Wonder if that's anything to do with it....

I think it's about £55 for a new part and from what I saw I don't think it needs re-coding or anything once fitted. Just clear any codes and perhaps force a re-gen so that once the new sensor is on you can start a-fresh with a clean DPF.

[jrw]

Just checked - Made in Malaysia

[Chrispy]

Ha, not fair. :-)

Been out in mine this evening to Asda and back. So far so good...... :-)

[jrw]

Just got to work and switched the engine off and the fans are running full pelt. You have jinxed me now

[alkip]

Checked mine last night too

Made in Malaysia although the ending letter on mine is a B, I presume this is just a further development?

[bond007]

a/b are for different engine codes so yours will be fine i think

[Fester1698]

well hopefully mine is now sorted as they have replaced the sensor