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eems wrote:Just to follow up on this thread, i've had the EGR valve blanked off since February and the engine has not made a single shudder in that time.

It's %100 EGR system *related*. Right after blanking the unit, the engine still shuddered in an identical fashion. But, with after an ECU reset, the problem hasn't reappeared.

It's possible a learned function gets disrupted because of the EGR's operation. Just looking at it logically suggests the EGR valve operating causes the ECU to learn parameters which lead to outputs that cause the engine to shudder.

In summary, the car had a shudder problem for 14 months until the EGR was blanked off and the ECU reset. It has been working well for 9 months. DPF still re-generates and the car drives fine. Economy is better.

The engine check light does come on every 1000-1500kms with an intake temp error, which is common when EGR's are deleted. Looking into an electronic fix when i get some time.

Hi eems, I'd be interested to know if the car has still been running fine with the EGR valve blanked off. Also did you just do this physically or had the EGR programmatically turn off in the ECU? or both?
Cheers

I see this is an old post, so not sure if this helps or the original poster's issues were solved but my daughter's foz was shuddering at between 2200 and 2300 RPM but we could not find any issues with it. The vehicle would shudder until you lifted the foot off the accelerator. We where looking at everything mechanical regarding driveline.. i.e. wheel balancing, wheel bearings, constant velocity joints, tailshaft universal joints, dual mass flywheel and/or clutch but never thought of DPF/EGR issues but after cleaning out the DPF and EGR system, all the shuddering has gone.

RSR 555 wrote:I see this is an old post, so not sure if this helps or the original poster's issues were solved but my daughter's foz was shuddering at between 2200 and 2300 RPM but we could not find any issues with it. The vehicle would shudder until you lifted the foot off the accelerator. We where looking at everything mechanical regarding driveline.. i.e. wheel balancing, wheel bearings, constant velocity joints, tailshaft universal joints, dual mass flywheel and/or clutch but never thought of DPF/EGR issues but after cleaning out the DPF and EGR system, all the shuddering has gone.

You could perhaps also check which firmware version your car is running. I think there was a firmware update that removed the issue, esp as it only seemed to occur in Oz to the early vehicles and seems to have vanished since. We had it once whilst the car was almost new, and under cruise control.

To me it had the feelings of a misprogramming where there is no hysteresis allowed, i.e. no overlap in on/off values and the same number is use to turn something on or off- when it hits X, something turns on, but 'cos X turns it off too it immediately turns off again... it's X so it turns on...and the cycle continues (thunk-thunk-thunk-thunk-thunk-thunk as you drive along). Note this is just an opinion/feeling...

pitrack_1 wrote:You could perhaps also check which firmware version your car is running. I think there was a firmware update that removed the issue, esp as it only seemed to occur in Oz to the early vehicles and seems to have vanished since. We had it once whilst the car was almost new, and under cruise control.

The firmware was replaced with the updated version with the previous owner (Subaru WA.. was a sales reps car) and the car would shudder with or without the cruise control set.

pitrack_1 wrote:To me it had the feelings of a misprogramming where there is no hysteresis allowed, i.e. no overlap in on/off values and the same number is use to turn something on or off- when it hits X, something turns on, but 'cos X turns it off too it immediately turns off again... it's X so it turns on...and the cycle continues (thunk-thunk-thunk-thunk-thunk-thunk as you drive along). Note this is just an opinion/feeling...

I'm sure there was some kind of overlap happening but the feeling was more in the driveline than the engine itself but (crossing all fingers and toes whilst saying this) all those symptons have gone and we can only put this down to either the DPF and/or the EGR system.

RSR 555 wrote:The firmware was replaced with the updated version with the previous owner (Subaru WA.. was a sales reps car) and the car would shudder with or without the cruise control set.

I'm sure there was some kind of overlap happening but the feeling was more in the driveline than the engine itself but (crossing all fingers and toes whilst saying this) all those symptons have gone and we can only put this down to either the DPF and/or the EGR system.

In that case I'm pretty sure you've 'hit it on the head' with your clean. Our car was (mostly) serviced by a Subaru dealer and 'decarbonised' for free at the 100000km service.

pitrack_1 wrote:In that case I'm pretty sure you've 'hit it on the head' with your clean. Our car was (mostly) serviced by a Subaru dealer and 'decarbonised' for free at the 100000km service.

So was Danielle's car for the first 125,000kms of it's life (so I'm asuming that they would have done the 100k service correctly???). The car was around 180,000kms when this shuddering started and no indication of any DPF or EGR issues, I believe these only showed up after the 70mm intercooler hose busted. We have only used Subaru oil and filters at every service and still isn't at 200,000kms to get the next 'decarbonised' service

RSR 555 wrote:So was Danielle's car for the first 125,000kms of it's life (so I'm asuming that they would have done the 100k service correctly???). The car was around 180,000kms when this shuddering started and no indication of any DPF or EGR issues, I believe these only showed up after the 70mm intercooler hose busted. We have only used Subaru oil and filters at every service and still isn't at 200,000kms to get the next 'decarbonised' service

I'm not old enough to remember the 50s and 60s but I'm old enough to remember the 70s where they used to talk about decarbonising engines and valve grinding every 50,000 miles. I even have a book (copyright 1972) with pictures of the process- along with wonderful cutaways, technical drawings and pictures of Laycock de Normanville overdrives, Fiat/Dino V6, Triumph Dolomite Sprints, BMW 3.0CSL & Renault 5 race cars, 50's Giulietta and 70's 132, and the wasteland that was a petroleum refinery in the 60's/70's.

With these diesels we've been driven (sorry) back to that era and if the electric vehicles don't get there first the petrols will catch up and kill diesel-at least for pax cars. If Mazda's HCCI (Skyactiv-X) petrol lives up to the hype it will make a pax diesel car redundant with the economy of a diesel and benefits of a petrol. Although I'm sure it will have its own whole set of issues...first one I'll nominate is probably an intolerance to fuel quality/composition variation. And i suppose if they produce soot or NOx through the combustion they might need a DPF for the soot and EGR for the NOx...uh-oh...

pitrack_1 wrote:I'm not old enough to remember the 50s and 60s but I'm old enough to remember the 70s

I'm not old enough to even remember the 70s

I'm guessing what Subaru told you at the 100k service and thier so called 'decarbonised' sevice was more likely just an intake system cleaner to get rid of any crankcase ventilation gum left behind in all the intake system. This stuff would have gone though to the combustion and cleaned everything along the way.

RSR 555 wrote:I'm not old enough to even remember the 70s

I'm guessing what Subaru told you at the 100k service and thier so called 'decarbonised' sevice was more likely just an intake system cleaner to get rid of any crankcase ventilation gum left behind in all the intake system. This stuff would have gone though to the combustion and cleaned everything along the way.

Quite possibly, although due to other factors I got the impression at the time that they actually pulled bits off to have a look.