Smax 2.2TDCi stuttering/kangarooing/stalling diagnosis

Smax 2.2TDCi stuttering/kangarooing/stalling diagnosis

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Nomag

Original Poster:

9 posts

151 months

Saturday 22nd August 2015
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Your advice appreciated please.

We have a 2009 S-max 2.2TDCi. About a year ago, at 66k miles, I noticed a slight hesitation and stuttering at low rpm, usually on a light throttle. Seems to occur at between 1500-1750rpm. Can occur in any gear and to avoid has necessitated using a lower gear than normal.

This has got gradually worse/more frequent over the last year, but occasionally I still get journeys where it doesn't happen. The car is also very difficult to drive in heavy traffic, as it seems to kangaroo in 1st gear, but I never notice this unless in stop-start conditions, which I rarely drive in.

Finally, today I noticed that on slowing down to approach a roundabout in 5th, the car stalled without warning. I am old fashioned and normally slow down through the gears, and this has not occurred for me before, however, my wife then mentioned that this has occurred several times when she slows down from 60mph in a high gear to turn into the track to our property. She never uses engine braking.
The car has now done 84k miles and I convinced myself this must be a combined clutch/flywheel issue and booked the car in at an independent to have replaced. I normally use a very good back street guy local to me but he doesn't want to do the clutch/flywheel so recommended another small garage.

I have now become concerned that I am barking up the wrong tree completely with this. There are no rattles etc. with the clutch engaged or not, and the clutch is not slipping at all as far as I can tell. Obviously there must be some clutch wear at this mileage, and it's going to need replacing along with the flywheel at some point, but the last thing I want to do is get this replaced and find the current problem remains. Could this be an EGR/DPF issue?

There are no warning lights on the dash, nor have there ever been.

Many thanks in advance for your advice.

andyiley

9,102 posts

151 months

Monday 24th August 2015
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The stalling issue cannot be caused by the clutch, so save your money there.

Quite what the issue is though, I am not sure.

stavers

251 posts

145 months

Monday 24th August 2015
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As mentioned - don't waste your money on changing the DMF or clutch. These will not be the route cause.

From the sounds of it the engine is struggling with mixture. I would be cleaning out the EGR valve as a first port of call.
Secondly, does the car pull strongly through the rest of the rev range? These engines have variable vane turbos which can get clogged up. Might be worth seeing if you can get someone to clean the vanes out as well.

Nomag

Original Poster:

9 posts

151 months

Monday 24th August 2015
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Thanks for the advice. I've booked it in for some diagnostics. It pulls strongly as normal through the rest of the rev range. I am suspicious about the EGR valve and will ask for that to be inspected carefully.

PaulV

292 posts

225 months

Tuesday 25th August 2015
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A simple thing to check is where the EGR pipe fits onto the intake.
My 58 plate Mondeo, when I bought it was so clogged there was only a 5p sized hole left clear of gunk.

Assuming it is the same layout , you need to loosen the pipe at the back (2x 5mm? hex) , one clip on the top and then you should be able to pull the front clear to see.

Nomag

Original Poster:

9 posts

151 months

Wednesday 2nd September 2015
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Update: had a mobile "diesel specialist" come out to the car today. He drove it and replicated the fault, which I have now realised only happens once the engine is warm.

He read two fault codes P2562 and P2563. These apparently related to the turbo charge pressure actuator and position sensor. He has suggested that the fault lies with the position sensor within the turbo actuator. His explanation was that the ECU can't determine what position the actuator is in correctly, so is constantly correcting, causing the surge. His explanation for it only occurring when the engine is hot relates to exhaust gas temperature.

He suggested we simply "drive around" the fault suggesting the actuator/turbo themselves are OK, but to replace the sensor would mean at the least replacing the actuator also, which he suggested would be expensive. I'm not really happy with this and want to fix the problem, but don't want to open up a bottomless pit of expenditure on different parts. To reiterate, the car pulls strongly through the rest of the rev range.

Could it be that, as suggested above, the vanes of the turbo are clogged with crud? Or could it just be the electronic sensor at fault? I'd appreciate your opinions and feedback before I go any further!

bearman68

4,642 posts

131 months

Wednesday 2nd September 2015
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Initially I suspected the EGR valve (Pumaracing will be along in a moment to tell me why it's not the EGR).
It's possible the EGR becoming blocked will effect the apparent boost on the turbo.
It's my understanding that the P2562 code may be turbo pressure below setting not the turbo position. If this is the case this is a more likely scenario.
However, if there is an electric actuator on this model, it makes more sense that the turbo position is incorrect.
Let's go with the last scenario for the moment.
If the turbo position is incorrect, then you may wonder if the control signal is correct. For this you need to read actual and desired turbo pressure / position and see what's happening. If the desired and actual are close,then the actuator is not the problem, and the sensor imputs into the ECU are incorrect. I would suspect MAF and air temperature sensor to kick off with.
However, if the actual pressure,and the desired pressure are a million miles apart, then you are back to the turbo actuator / forced induction system. It's not a huge cost to eliminate the EGR. EGR will normally only operate on a hot engine, so this may be why you are only seeing it then. However, EGR will tend to cause the engine to produce white smoke, and run badly around 2000 rpm on no load. (my experience). If there is evidence of this, may be worth getting in there for a poke around, or even remapping the EGR out, and disconnecting it.
Further tests can be done on the turbo actuator, by looking at the pressure signal against the actuator current. The current will determine how the actuator is operating, and how hard it's working. If this is consistent with the engine pulsing, your mobile diesel specialist has probably identified the issue.

Hope this helps.

Pumaracing

2,089 posts

206 months

Thursday 3rd September 2015
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bearman68 said:
Initially I suspected the EGR valve (Pumaracing will be along in a moment to tell me why it's not the EGR).
I wouldn't dream of it dear boy. Intermittent faults with new fangled turbo diesels are well out of my wheelhouse. A man's gotta know his limitations.

I am however quite intrigued as to what a "route cause" is. I suspect it's something to do with how one decides which roads to take on a particular journey but I could be wrong.

bearman68

4,642 posts

131 months

Thursday 3rd September 2015
quotequote all
Pumaracing said:
I wouldn't dream of it dear boy. Intermittent faults with new fangled turbo diesels are well out of my wheelhouse. A man's gotta know his limitations.

I am however quite intrigued as to what a "route cause" is. I suspect it's something to do with how one decides which roads to take on a particular journey but I could be wrong.
Route cause - determining which road to travel down to find the cause of the problem smile

I might be completely wrong in the diagnosis, but I did spot that you'd be onto this at some stage....beer

Nomag

Original Poster:

9 posts

151 months

Friday 4th September 2015
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Thanks for your learned advice. Discussion to be had with my mechanic next week. Trouble with these faults is it's a bit of a minefield. Keep thinking I should just get rid and replace, but the car does everything we want it to still, and there is no better replacement available. I'm loathed to spend upwards of 26k on a new, similar spec model!

ecymmjc

2 posts

58 months

Monday 13th May 2019
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Hi Nomag - how did you get on with your stuttering issue? Did you solve it?? I think I have the same thing. Thought it was the autobox to start with but local transmission specialist says its definitely not the gearbox. It's very rapid (though occasionally overlaid with a slower cycling wavering of the power delivery) so must be either fueling related, engine management related or ABS related (yes the stuttering feels like the brakes going on/off very rapidly).

E-bmw

9,102 posts

151 months

Monday 13th May 2019
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That was 2015 & the OP hasn't posted in a LONG, LONG time, so don't hold your breath for an answer.

rallycross

12,742 posts

236 months

Monday 10th June 2019
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I’ve had a few 2.0 tdi Smax auto’s recently when they have a few miles on them they can be quite jerky on a very light throttle ( just the lightest touch on the pedal at low speed can make them kangaroo a little bit). Just apply more throttle and the problem goes away.

ecymmjc

2 posts

58 months

Friday 27th December 2019
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Hi guys, I had a similar problem of stuttering while driving* that was diagnosed as the turbo return pipe. Dealer fixed it for £180.
I was convinced it was the gearbox to start with as it was such a judder like the brakes going on/off rapidly.
An independent garage previously misdiagnosed it as a MAF sensor which I had replaced but didn’t fix the problem.
In general the car is great and pulls very strongly in all gears, however, on a long run today while on cruise control at 70mph the car seemed to do a slower cycle stutter. It also sometimes has a rough idea when cold like misfiring or a bubble in the fuel line (which there can’t be as driving fine), once in gear and driving it’s fine.

So I guess there may be another issue brewing, maybe with the turbo, or glow plugs??

  • started at 70mph very intermittently and seemed to be related to light or backing off the throttle but got worse over time until it was happening every minute. I was very nervous about taking it to the Ford Dealer but they were excellent (Trust Ford in Bookham, now sadly closed).
Edited by ecymmjc on Friday 27th December 17:50

GreenV8S

30,149 posts

283 months

Friday 27th December 2019
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ecymmjc said:
turbo return pipe
What is a 'turbo return pipe'? Are you referring to an oil return, some part of the EGR system, a recirculating blow-off system?