After having problems with our Sedici, reading many threads and researching other diesel owner issues am gonna try explain the main problem and some remedies related to the 1.9 diesel, Multijet.... fitted to many cars... not just Fiats.

This will hopefully be helpful and also simplify for the not too mechanically minded having the same difficulties.

It's best to understand what is under the bonnet that's causing this great engine the running problems and also what the main dealer will most commonly try charge you for....

EGR = Exhaust Gas Recirculation Valve... basically a valve that opens and closes to allow burnt engine gasses back into the engine. This has been added to reduce NOx (nitrogen oxygen) by reducing combustion temperature.
It is the main culprit for poor engine running so is worth taking time to understand how and when it works if you are having flatspots at just under 2000rpm (a very common issue often solved by blanking off... if you do this a fault will be detected and your management light will activate).

Because the EGR bypasses burnt gasses from your exhaust that contain soot they become fouled up and will eventually seize unless cleaned regularly... this is important as they can allow too much soot into the engine which in turn clogs the DPF (Diesel Particulate Filter... will explain later).

IMPORTANT: Read this bit.. The EGR is made up of two parts... the easy to see once removed, opening, metal, spring loaded valve but also the often overlooked solenoid part.
The solenoid part fits above the lower valve and controls the opening/closing. It can become corroded inside which may lead to fluctuating valve operation.
We beleive this is what is causing the flatspots.

To explain further...

EGR is opening under gentle acceleration = stuttering due to sticking solenoid

EGR is closed under heavy acceleration to allow more fresh air + better performance = smooth acceleration.

Here is a very useful thread describing a technique on how to clean the solenoid part of the EGR http://www.astraownersclub.com/vb/showthread.php?t=243540
Many thanks to the Astra club for this.

After experience it's worth noting that....
Buying/fitting a new EGR doesn't mean it will work okay... if it has been stored for a while the solonoid components may have corroded/dried inside leading to another faulty unit!!
The EGR units sold by Fiat, Vauxhall, Saab are made by the same manufacturer (Pierburg) and are interchangeable... just find the right part number and search on-line for any cheaper options. (be aware warranty issues)
If you do decide to strip the solenoid, clean and lubricate there is a debate on what type of oil to use... grease may be too thick and restrict smooth movement, WD/40 spray oil may freeze in severe winter temperature.
The recycled exhuast gasses will eventually clog other engine components even if the EGR is working properly.... the inlet manifold is an expensive victim!!

Blanking off the EGR is a good way to check if you have a faulty EGR.
This involves fitting a thin metal plate between the EGR and incoming pipe.... take for a test drive and see if there's an improvement.
These are available from E-Bay http://www.ebay.co.uk/itm/EGR-blanking-plate-VAUXHALL-OPEL-FIAT-SAAB-SUZUKI-1-9-ALFA-1-9-2-4-CADALLAC-/120857185986?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c23a64ec2
It will trigger your management light but once removed is reported to reset itself after a few miles by another helpful member... be aware making your own version is a risk if it corrodes/collapses and is sucked into the engine (this has happened!!)
Here is a useful link for locating/removing the EGR on a similar, not identical, Multijet https://www.fiatforum.com/grande-punto-guides/178715-cleaning-egr-valve.html

Permanent blanking of the EGR is possible with an...
ECU = Engine Contol Unit (the cars electronic brain) re-map to stop the management light... it is recommended to ensure the DPF is removed though. Think this is due to the increase in combustion temperature...

The...
DPF = Diesel Particulate Filter... is the diesels equivalent to the petrol catalytic converter. Fitted to the exhaust and introduced to reduce the black smoke seen coming from the exhaust under heavy acceleration.... needed for the increased smoke caused by the diverted EGR gasses!
The DPF is basically a filter that collects soot before it leaves the exhaust. These become clogged so at a certain distance do a...
REGENERATION = (injects diesel to burn off deposits) problem being the engine doesn't always get hot enough to burn the diesel.
This is why they are not recommended for repeated short trips and are very expensive to replace.
A cheaper option is to go for a DPF removal/EGR blank and ECU re-map (will explain later).

To help protect the engine an...
OIL DEGREDATION = (oil change timer) is programmed into the ECU and effects if it will allow a REGENERATION to occur. The ECU apparently takes a few parameters into account like driving style and time then decides if your oil is safe enough. It does this because over time the oil can become contaminated with un-burnt diesel thus making it risky to perform the REGENERATION. So if you ignore the oil change light for too many miles your DPF will eventually clog and fail.
If you are doing your own oil changes or getting your local independent garage to do it this must be reset or your ECU won't know and will do fewer REGENERATIONS.

Have heard the ECU, OIL DEGREDATION can be reset by using the...
OBD = On Board Diagnostics System... This is a connection to access your cars ECU. This means even you and I can read/reset any stored fault codes not just the main stealers by using the correct diagnostic lead, laptop and FiatEcuScan software. The connection should be located under the drivers side dashboard.


The DPF removal/EGR blanking ECu re-map services offered by various garages have their pro's and con's that should be considered.

Downsides would be....

Voided manufacture warranty,
Care must be taken if servicing is done at a main dealer so as not to restore the re-mapped ECU to its original protocol,

Upsides should be...

More horsepower,
Better MPG,
Blanked of EGR so no more soot forced into the engine.
Will eventually pay for itself due to the fuel saving.


Questions have asked were.....

Will it fail the MOT?...... NO.
Can I take the working DPF out and sell to raise funds?..... NO. Due to new laws the orginal DPF needs to be stripped of its internals and re-used.
Will the car be charged more road tax once emissions tested?..... NO.
Will the car still regenerate?.... No. All issues will be removed from the ECU including the "Oil Degredation" as no longer needed.
Can i still use the "OBD2" connection and "FiatEcuScan" software without corrupting the ECU?.... YES.
Will the ECU still send error/fault codes from other components if needed?.... YES.

A few unknowns... Do you inform the insurance of the ECU remap?..... will the car start to smoke like an old taxi cab?

Taken a lot of time to write this but still have to say we would still buy another Sedici Multijet diesel!!! The engine and car are great... just let down by the restricting add ons.

Hope this has been a good read and most importantly helped out.... let us know.

this info is outstanding, but was informed as of 20/03/13, (strange date to start something, i know) that an illuminated engine managment light on a disel is now a MOT fail....i argued the toss about my blanking plate and they made it advisory on this occasion.... looks like i'll be going for the 10mm hole....

Excellent article; be aware that if the DPF regeneration cycle is incomplete diesel fuel ends up in the sump; this is noticeable as a rising oil level(!); this fuel can be picked up by the pistons and result in a runaway engine that will eventually self destruct; if you leave the EGR valve electrically connected then the warning light does not come on even if blanked off (important to put blanking plate on the exhaust side of the EGR to stop it sooting up and restricting movement as if the valve cannot move that will trigger the light); see my other posts re this.......

I found this thread very useful for recent problem with Doblo 1.9 diesel. Replacing the EGR has sorted the sluggish flat performance, and it is now like driving a new car.

On the basis that the EGR was not performing properly due to wear and tear, and its worn out springs; I decided to replace rather than trying to clean existing.

During the replacement procedure, I removed the return pipe extending into the engine cover and gently removed, cleaned out all the heavy sooty deposits using a old sweatshirt rag wrapped around a short timber stick. I guess these heavy deposits were the result of the EGR malfunction possibly due to the previous owners driving habits ?

beauxreflets said:

I found this thread very useful for recent problem with Doblo 1.9 diesel. Replacing the EGR has sorted the sluggish flat performance, and it is now like driving a new car.

On the basis that the EGR was not performing properly due to wear and tear, and its worn out springs; I decided to replace rather than trying to clean existing.

During the replacement procedure, I removed the return pipe extending into the engine cover and gently removed, cleaned out all the heavy sooty deposits using a old sweatshirt rag wrapped around a short timber stick. I guess these heavy deposits were the result of the EGR malfunction possibly due to the previous owners driving habits ?

Click to expand...

No. those deposit will occur regardless of driving habits or a faulty ERG valve. it was well documented a decade ago by magazines like diesel car,now called what or which diesel.

I changed my EGR valve back in February this year as the other one had broken. Needless to say, I've been suffering from flat spots, hesitation and kangarooing.

Took it all apart and cleaned it this weekend and the car now drives like new. It's quieter, more free revving and seems quicker. However, the engine management light has come on and the warning flashes up 'Check Engine Glow Plugs'.

Has anyone else come across this? Will it clear itself when the car works out what's gone on or do I need to have the code cleared down?

As always... any info gratefully received.

Thanks

Dan