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Hi everyone,

I have a 2009 2.4 spider and it's developed some real problems. Last week I got a warning saying that the DPF filter was blocked, but I drove on a long run from Hereford to Manchester and back, and it disappeared. Then, on my way to work last Saturday it went into limp mode, and every time I restarted it would clear but come back within around half a mile. It did the same on the way home, and then it finally stalled about half a mile from home. I managed to start it and just about it limp it , but it didn't sound good and had no guts whatsoever. I read a few forums and the advice seemed to be that it was either a low powered battery, a dirty EGR or a blocked DPF filter.
So, I got a new battery and I cleaned out the EGR, but neither made any difference. Now though it won't start at all. After maybe 12-15 attempts it will cough to life for about a minute but then stall again, but when it does run it sounds really rough and it blows out a LOT of white smoke. We've plugged in a diagnostics jobber, but all that's on there is the DPF warning. This clears but then comes up again when you finally get it to run briefly. I rang a local garage but they said whatever the problem is, it isn't the filter. Does anyone have any experience with this or know what the cause may be? Thank you in advance for any help, and sorry for the essay!

Craig

By the way, it's not down to me putting petrol in, and a mechanic mate is confident the head gasket hasn't gone.
 

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Hi everyone,

I have a 2009 2.4 spider and it's developed some real problems. Last week I got a warning saying that the DPF filter was blocked, but I drove on a long run from Hereford to Manchester and back, and it disappeared. Then, on my way to work last Saturday it went into limp mode, and every time I restarted it would clear but come back within around half a mile. It did the same on the way home, and then it finally stalled about half a mile from home. I managed to start it and just about it limp it , but it didn't sound good and had no guts whatsoever. I read a few forums and the advice seemed to be that it was either a low powered battery, a dirty EGR or a blocked DPF filter.
So, I got a new battery and I cleaned out the EGR, but neither made any difference. Now though it won't start at all. After maybe 12-15 attempts it will cough to life for about a minute but then stall again, but when it does run it sounds really rough and it blows out a LOT of white smoke. We've plugged in a diagnostics jobber, but all that's on there is the DPF warning. This clears but then comes up again when you finally get it to run briefly. I rang a local garage but they said whatever the problem is, it isn't the filter. Does anyone have any experience with this or know what the cause may be? Thank you in advance for any help, and sorry for the essay!

Craig

By the way, it's not down to me putting petrol in, and a mechanic mate is confident the head gasket hasn't gone.

You need someone with a proper scanner to plug the car in. They will be able to see how blocked the DPF is. I had a 159 which was totally blocked. Managed to force it to regen and it ran ok after but was 70% blocked so would need changing eventually. They may be able to force a regen to bring the percentage it is blocked down so it can at least run.

No matter how much you drive it it will not clear the dpf if it has gone to far. If your Birmingham way a friend of mine has a snap on scanner and can perform a regen if required.

Other than that it could be a number of things, but you need to read the data regarding the DPF. Other things to check would be the amount of fuel the injectors are returning back with a leak off test.

hth
 

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TL : DR = DPF Soot can be removed, DPF Ash can't. Maybe look into new, good quality, DPF. Maybe an EGR & DPF Delete with Remap.

in addition to DPF Soot content (the figure that everyone commonly knows as the 'fill percentage') they also have an Ash content value. Ash content is very hard to accurately measure and is usually a 'calculated' figure with some clever math employed by dealer level diagnostic kit (id be suprised if its intergrated into programs like MES or handheld generic scanners) that is based on number of regens/regen times/successful regen completions/exhaust gas pressure differential between upstream and downstream of the DPF etc etc.

The engine ECU clears the DPF of soot by periodically increasing the amount of fuel injected. This raises the temperature of the exhaust gasses to around 450-500*C, regens will start at anything over 200-250*C (I've personally seen active regen temps of >800*C, but it depends on which technology of Regen is employed by the manufacturer). The ECU doesnt, however, account for Ash removal.

in my experience (2 years with Mercedes commercial vehicles) it is *sometimes* possible to lower the ash content with a good run in 3rd or 4th gear at motorway speeds with a forced regen. The problem is that with each regen (passive or active) you create more ash. The larger ash particles are more difficult to get out of the DPF, which is why the higher engine speeds are needed but its a vicious cycle... regen creates ash, ash blocks a DPF, flow is restricted through the DPF and critical engine speeds cant be reached because of back pressure, which means the ECU thinks the DPF is blocked with soot, ECU activates a regen, regens create ash... rinse and repeat.

You *may* be experiencing a DPF blocked by ash rather than soot. There are companies who jetwash the ash from the DPF but i have never heard of it being 100% successful. For a similar price of a decent quality DPF, you can get them removed and have an EGR and DPF delete 'remap' on the ECU, never to worry about it ever again. ultimately its upto you but the option is there.
 

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Discussion Starter #4
Thanks for the replies, a lot of good information that I was pretty green and clueless on. So do you think that the symptoms do point to a blocked DPF?
 

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Thanks for the replies, a lot of good information that I was pretty green and clueless on. So do you think that the symptoms do point to a blocked DPF?
if no one tells you, you wont know ;)

it may point to a blocked DPF...

i think you next step is to get the Engine ECU read for codes, maybe hook up MES from a local AO member, if you dont have it yourself, DTCs are a much needed source of info in this day and age and without them we will be stabbing in the dark. :)
 

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Discussion Starter #6
if no one tells you, you wont know ;)

it may point to a blocked DPF...

i think you next step is to get the Engine ECU read for codes, maybe hook up MES from a local AO member, if you dont have it yourself, DTCs are a much needed source of info in this day and age and without them we will be stabbing in the dark. :)
I'm really showing my ignorance here, but what are DTC's or an MES? I'm an engineer by trade but I've never really had anything to do with cars (mainly warships!), plus this is my first Alfa.
 
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