DPF Troubles - break, sell or fix?

[eltax91]

Hi guys

I have a 55 plate Mazda '6, with the 143 bhp 2.0 Diesel engine in it, which I bought 4 months ago for £3550. Recently, I had a regularly occuring DPF light, which came on for 10 minutes of motorway driving then went away again. I asked a local garage to remove the DPF and to fill it with a specialist cleaner, which they said they have done on other vehicle.

They did this, and have also carried out a DPF regen using some generic Snap-on diagnostic equipment. The problem is, the car keeps popping up the flashing DPF light, and occasionaly the engine management light. The fault codes are reading as o2 and dpf temperature sensor faults. I am currently diriving around with a fault code reader plugged in so I can keep clearing the codes!! When cleared the car boots fine and drives well, when the DPF light is flashing it still boots, but with stunted performance.

The situation i'm in is I run my car for work, and receive a car allowance for doing so. My boss insists I have a reliable car, so I have this morning robbed all the spare cash I have and agreed a purchase on a PD130 Octavia.

So, I now need to regain as much money as I can on the Mazda, do I:-

• Keep trying witht he garages to fix it, then sell privately (a new DPF is silly money, over £1k)
• Sell it as-is, stating the issue and get the best I can for it
• Tear it to pieces in my garage and sell engine/ box/ body and scrap the rest
• WBAC it and wave goodbye with zero fuss?

Any half decent Mazda Tech out there want to take a punt on it?

[eltax91]

RobCrezz said:

Go for this IMO.

Will this produce an extra £600 come resale? Also, the costs of a day trip to Sinspeed in London have to be accounted for

[eltax91]

HellDiver said:

You do know that your local remapper will remove the DPF and map out the DPF functions on the ECU for £300-400? Best solution for anyone with DPF issues.

My local folks are doing the service for the 2.0D Mazda 6 and the 2.0TDCI Mondeos for £400. They remove the DPF, knock the guts out of it, refit, then map out all the DPF functions. They'll also add an extra 30hp if you want while they're at it. An extra £80 they'll give you your DPF intact, and fit a bypass pipe.

I've been downb that route already. Nobody except the expensive SinSpeed can say they have done this. They all say they've done it on a mondeo, not on a Mazda 6. I went to the hassle of taking it to a remapper at Rockingham race circuit. He tried for 12 hours, and good not read the ECU due to the encryption in place.

So, it's a solution for all DPF's, except Mazda's.

[eltax91]

y2blade said:

how much have to spent trying to fix the Mazda?
what MY is the Octavia?

My garage is quite friendly, so I'm only out of pocket £70 currently on fixing the Mazda! They are going to try a further regen and recalibration on Friday.

The Octavia is a 54 plate, PD130 WITHOUT a DPF.

[eltax91]

GreigM said:

This is a real pity, as I have a 53-plate Mazda 6 (pre-DPF) and its a really great car, over 120k miles now and drives like its brand new

Yeah it's a massive shame. If only I'd have researched into DPF's first! I just cannot have an unreliable car, my work depends on it. My previous Octavia was faultless, so I'm just hoping this new one will be too.

[eltax91]

RobCrezz said:

I dont see how this DPF issue is making your car unreliable? Does it stop it working?

Yes and no. Limp mode, whilst still driveable is a pain in the arse. Also, the fuel economy drops by around 20% when the DPF is clogged up. It's the time spent troubleshooting which hurts me. Lots of time messing with fault codes and doing a regen/ racalibration. Also, Mazda say the oil should be changed at each DPF regen (although my local guy is not doing so) because it's a "wet system", so unburt diesel is returned to the sump when the DPF fails to regen.

There seems little other option when it can't be bypassed and a replacement costs such a fortune. What the hell is in these things to cost so much I don't know. all I hear is "precious metals" when I ask.

All-in-all, the time its spent in the garage reminded my boss to have a chat with me about the fact he pays me a car allowance to have a reliable car... hence i've gone out and bought one.

[eltax91]

So, anyone want to buy a Mazda '6. It's in great nick, I'm gutted to be selling it.

[eltax91]

HellDiver said:

Except our local guys specifically say they do it on Mazdas. A few of the local cabbies have had it done, no problems.

You're not asking the right mappers.

Don't suppose you could pm me some more details, could you?

[eltax91]

So all. It's looking like I'm going to have to sell it as broken. The fix is looking like it will cost too much.

Anyone want to hazard a guess how much I'll get back for the old shed with a flashing DPF light?

[eltax91]

v8guinness said:

Presumably these sensors (Lambda/Hego & Exhaust Gas Temp) have actually been checked, wiring, connectors and actual sensors, it could just be that the diagnostic fault codes are trying to identify a specific fault. Errors with these would leave the car struggling to regen.

It's not usually necessary to change the oil every time a regen is triggered by a Service tool, but if there have been regen issues it would be very prudent to change the oil!

The garage is going to test the centres this week and see if they need replacing. So I maybe out of the woods with a working car.

I would be interested to know more about how I might NOT be able to delete the warnings using diagnostics kit, if anyone know more detail.

[eltax91]

nottyash said:

Its people who dont do the milage that causes problems. So buying one if you drive 3 miles to work is just plain stupid.
I dont have any problems doing 40 miles a day.

And I was doing 100 miles a day when I owned the car that started this thread, the dpf was still st....

[eltax91]

Flying machine said:

Out of interest is the diesel mazda 6 particularly bad for dpf issues? My brother in law has one and is having this problem

Yea, they are a pain in the back side. To top it off, the design of the thing means that if the car attempts a regen in the right conditions and it fails, the unburnt fuel is dumped into the fking oil sump!

This means its not long from a failed regen to an oil change. I had half a dozen oil changes along with dpf troubleshooting before I finally gave up and through the sack of st on eBay. Bought for 3550, kept 6 months and sold with dpf light flashing for 2000.

At one point I was manually clearing fault codes whilst on the move to try and clear the fking thing out.

Biggest car mistake I ever made and will never have another piece of that wky bks engineering again.

I hope to hell the tech gets better before my PD octavia is no longer usable.

[eltax91]

corvus said:

Your Octavia should run and run. If it's a PD130 or early 105. Rough old engines but bulletproof IF properly serviced as per the Teutonic mindset.

Yep, its the PD130. It's my second octavia, only upset by the interlude of the bloody Mazda. the first one I took from 77k to 176k and it was still as tight as ever. Sadly I wrote it off. this one is showing no signs of slowing yet

[eltax91]

Pesty said:

Everybody slagging off mazda 6's I thought Mondeo's had the same engines? everybody seems to think them reliable(not me mine was a bag of ste)

I stand to be corrected, but I think its a shared engine but individual exhaust/ dpf system. Mazda's was ste, ford learnt from their mistake and made it less ste