Help ?

My 56 plate Doblo 120 Mjet has been misbehaving recently. 'Engine Failure' warning has come and gone randomly, mostly with no effect on performance, rarely with a limiting effect, but not so severe as to be a 'limp' mode.

Then....
Oil change light came on, I changed the oil...
Oil change light stayed on (I know about his now!)...
Engine failure warning starts to come on more often...
Engine often 'stutters' when throttle is balanced/feathered...
Rear fog failure warning under braking...
A couple of days ago, revs drop and car will not accelerate / drive above 1st. My wife pulled over to let traffic past and then could not drive off as engine would stall as soon as clutch pedal released. She got it home after stalling many times...
...car is now on drive.

Starts, runs, but depressing accelerator to floor results in revs rising slowly to 2-3000 rpm, more smoke than usual from exhaust.

Any ideas please ?! I have bought a KLL lead and ecuscan with the intention of looking for fault codes related to oil status and DPF level but I can't get the thing to work !

Quick update :

Having started the car earlier today, engine would not rev at all - even invoking the PAS stalled the car.

An hour ago, I started it and could get to 2000rpm. I decided to try to limp to a garage, but in the end it wouldn't pull up the first incline I came across, even in first gear.

Looks and smells like steam coming from the exhaust too.

I finally got fiatecuscan working on this problem.
Fault codes referred to clogged DPF, and degraded oil.
Oil has been changed, so I have reset this, but it would seem that the DPF is now beyond regeneration because I could not successfully force one.

I am going to try and remove the DPF and attempt to clean it before I resort to replacing it.

Has anyone tried this / heard of anyone having any success ?

I have read all sorts of suggestions...compressed air, jet wash, de-ionised water....

there are company's out there that will change ecu setttings to remove the dpf , and physically re move it , not cheap , but replacing dpf is not either. plus your car will be happier. must be covered on this forum some where . mike.

Yes I'm sorely tempted for about the same money as a replacement DPF, I especially like the sound of better mpg, as I am always disappointed with the Doblo in that respect.

However, I have decided it would be extraordinarily selfish to save a few £££ at the detriment of other people who may eventually breathe in even a fraction of the particles that would be produced if I have the dpf removed. A bit like a smoker not giving a s**t about non-smokers in the same room.

I hate breathing in other people's smoke.

Therefore, I am commited to repairing or replacing the damn filter ! Even though the car industry must be capable of a more robust solution to diesel emissions.

Thanks for the suggestion, though.

In the Croma section dave recently cleaned his blocked DPF successfully. Think he used acid brick cleaner or something like that.

fleabay seems to have some cheaper choices, personally i would make my car quicker and more m.p.g ... as dpf will probably come back to haunt you. mike.

Missing dpf=mot fail (in future)

Not getting anywhere with this so far.

I originally got a fault code relating to pressure differential which is what interrupts a forced regen when attempted.

My doblo is returning a reading of 250mBar, whereas my fathers doblo reads 15-50mBar. I have swapped sensors but that made no difference. The hose/pipe from the dpf to the sensor looks ok.

Why would it read so high ?

gallon of brick cleaner + jet was fixed mine

Hi I am new to the forum & have an 06 doblo 120 same as you which I bought new I have experienced all these problems & more so the following information relates to my methods of dealing with the problems which you may find helpful
Cleaning the DPF yes I have successfully cleaned mine twice .First when 240% blocked .Second when 360% blocked on each occasion the garage said it was unrecoverable & needed replacing So I had nothing to lose .
So remove the dpf Do Not Wash It Out .as the filter is blocked with oily soot adding more moisture will only make it harder to clean .
You need heat and plenty of it I used a gas torch the type roofers use prop or hang the dpf up vertically inlet at the bottom .position the gas torch underneath a few inches below the dpf & light it up it needs to get hot.
There is a cat in the first section of the dpf this should look white hot on the car it would reach 600Deg + while doing a regen so you are trying to do the same I left mine burning for 20 min then let it cool down

This should burn all the greasy oil out of the dpf & leave just the fine dust which you need to remove as much as you can.
Once cool I used a vax type hoover attached & sealed into the inlet end of the dpf (Make sure you have a bag in it) While the hoover is working start lightly tapping all around the dpf to loosen the dust you cant see it coming out but it will be so keep doing this for ten min or so and that should be it ,
You can’t tell how successful the cleaning has been until its back on the car if you have a registered version of fiatecuscan you will be able to check it & do a regen which it will need to complete the cleaning process .

Before doing a regen you should try and find out why it blocked up. This is usually the type of use lots of town driving kills the dpf so it needs longer faster runs often
When I did mine I cleaned & serviced the egr valve & maf sensor before starting the car In my case after cleaning the dpf was down from 360% to 120% blocked so a lot better but not clean enough but I could then do a regen which brought it down to 28% now that’s what I call a result. Considering the garage wanted £1200-00 to fix it

You should also remember the following before doing a forced regen otherwise it might not start or complete it properly.
Clear all faults (No warning lights on)
Oil degradation no lower than 40% better still change oil & reset service
Engine temp 75+deg
Don’t touch clutch or brake ether will stop regen
I am assuming you have a registered version of fiatecuscan which you mentioned in your post if not then I would get one it’s the best thing I ever bought saved me lots of money with my car.

Hope some of this helps
RAA

Thanks everyone so far, RAA I will be grateful for you sharing your experience if I resort to cleaning the filter. So far, I tried removing it from the exhaust but just about every nut and bolt was seized. During this, I noticed a big leak from between the cat and the exhaust pipe with the flexible section in it. Turns out one of the studs securing it had snapped - looks like an old issue as everthing is equally coated in rust and muck.
I have removed the remains of the stud and put the exhaust back in place to see if I have eliminated the leak, but the car wont start now ! The first time I tried, it caught but stalled, each attempt since has seemed less and less likely to start up until the battery started to fail.
Once charged, the same thing happened...first attempt fired but stalled, subsequent attempts sounded hopeful but did not actually start.
While meddling with the exhaust, I cleaned the EGR which involved moving the fuel filter. As mentioned previously, I have disturbed the pressure differential sensor also although it is back in place now.

Why won't it start ? It seems so willing !

RAA, ecuscan shows DPF at 104% and 'normal clogging'.

Better news today, dropped the exhaust off again by uncoupling it after the CAT, and the car fired first time and runs (though I daren't run it for long).
Revs freely and engine failure warning and lamp has cleared from the dash...result !!!
It would seem there is a massive blockage within the exhaust system which might explain the pressure readings and makes sense of the starting problems too.
I just have to identify which bit is at fault - hopefully the back box (unlikely ?) hopefully not the DPF (more likely ? More expensive !).

Thanks for your suggestions so far, I hope this will help someone else in the future.

I'll let you know how it gets fixed.

Ok brizz
The fact that the car starts once you remove the exhaust indicates that as feared your dpf is blocked but 104% is not unusual & should not stop the car from starting the high differential pressure is a different matter this normally indicates how bad the blockage is & I would not expect such a high reading for a 104% blockage?
My car has never refused to start even when heavily blocked in theory when you start the car it doesn’t know the dpf is blocked until the engine is running and the sensors start sending back information this takes a little while and it should continue to run while this is going on Once it senses a blockage which is indicated by a high differential pressure it would normally fetch engine light on but not stop engine?

So I think you should look at other causes for the not starting problem other sensors fuel system loos connections etc it’s a lucky dip sometimes however I am intrigued by the fact that it did start when you removed the exhaust so have you tried clamping or removing the rubber joint on the differential pipe at the dpf therefore eliminating the backpressure to the sensor so it thinks there is no blocked & then try starting it?
Good luck
RAA

RAA,

I removed the back box of the exhaust, the DPF and the flexible pipe after the cat. As soon as the DPF goes on, the engine won't run (no gases come out after the DPF). It seems to me that the blockage causes exhaust gases to stop the engine running as they cannot escape (?).

I have since cleaned the DPF (used acid brick cleaner and a jet wash - plenty of filth came out, and the visible internal parts of the DPF are clean to look at now). The car will now run, but if it is revved hard, engine light comes on and limp mode also = limited to just over 3000rpm. DPF clogging still at 104% - does this work like the oil degradation in that it is not measured, but calculated based on use/regens ? Differential pressure still high and forced regen stops when engine revs past 3000, even though all codes were cleared first.

Since putting everything back together I have had warnings for all sorts of bulb failures as well as ABS light when revving engine (!) and glow plug failure warning. Haywire, basically.

Now each time I reset the faults, after running/revving I get :
P0683 - Preheating control unit (feedback)
or
P0401 - EGR valve

and always

P1206 Clean or replace particle filter.

Differential pressure is still in the 100s of mBar.

?

after i'd brick cleaned mine i went to test track went as fast as i could so engine and exhaust got hot, pulled into a layby i then reset fault codes and did forced regen, been fine since

Dave,

Do you recall what sort of readings you were getting from the pressure differential sensor before / after cleaning and after regen by any chance?

br1zz said:

Dave,

Do you recall what sort of readings you were getting from the pressure differential sensor before / after cleaning and after regen by any chance?

Click to expand...

you can see them in the screen shots in this thread https://www.fiatforum.com/croma-ii/308653-dpf-clogged-regen-failed-maybe.html