2010 Diesel Drivetrain shudder

[El_Freddo]

G'day Cihan - welcome to the forum!

Good to hear that you've looked in to it and had a go at experimenting with things. I just hope that it doesn't void your warranty!

The other thing I wanted to know is if you've taken this up with any subaru dealerships to see if they've been looking into this side of things - who knows, you may have just hit the nail on the head with this one!

Cheers

Bennie

[pitrack_1]

I plan to block it off / physically disable the valve if the cars fuel economy is going to remain 15-22 percent lower and the shudder is eliminated.

What'll you do if/when the DPF overfills due to no/ineffective regens?

Shuddering just (re)started for me recently at 40,000kms. Seems to be a common number. Had one today and I'm pretty sure it was at the end of a regen- reduced response and decreased fuel economy had been happening for 15? mins prior and response/economy came back when the shudder happened.

[eems]

G'day Cihan - welcome to the forum!

Thank for the welcome Bennie.

I'd think Subaru already understands the problem and knows the solution, it'd be down to cost minimization at the moment. First they'll try to 'ECU flash' the problem away, and then they'll replace the hardware in the worst cases.

I could be wrong because being in limp home mode evidently disables more than one system. But it's pretty conclusive to me going from experience in tuning with EGR systems (and disabling them in performance applications). If they're open too far the engine basically chokes. If the frequency / timing is off the unit doesn't operate at the correct effective duty cycle just like any other similar electrical device. If the unit is too far open with high exhaust back pressure - there's going to be a problem. Long term the whole intake manifold will choke up with carbon and soot.

I guess the effort was to prove my earlier suspicions about Subaru's response via their service department. IE not 'lugging' the engine, using the 'revised' shift schedule, using 'high quality' fuel etc, which is all just tangential time wasting in my opinion. Sure there's valid cases where short trips cause DPF problems, but that's already in the manual i read from start to finish when i bought the car.

Bennie, i'm confident that the dealerships have no idea. If they do, they won't act until the 'mod' funding is granted from Japan. I think the more expensive the fix, the longer it's going to take. Its been close to 2 years now? I'm curious to know how well Subaru will look after owners when the 3 year warranty expires?

What'll you do if/when the DPF overfills due to no/ineffective regens?

Hi Pitrack,
I agree, EGR delete means DPF has probably got to go also.

[thunder039]

i was reading on subaru website that they have revised the diesel engines for the forester in the outback and have adjusted things like timing and turbo.
not only have they got better fuel economy now, claimed 6.0l/100km! which is nuts but there is a good chance if they have revised the motor they may have fixed the shudder

[El_Freddo]

but there is a good chance if they have revised the motor they may have fixed the shudder

*May* - that's a big call and probably a product of subaru's marketing (spin) department. Yes they've probably looked into it and done some stuff with the engine etc but I highly doubt they've actually solved it yet.

Cheers

Bennie

[thunder039]

on there webiste it doesnt say they have fixed the issue and nor do they even mention it.
they still may of fixed it but don want to publise it due to then they will be admitting there was an issue in the firt place

[eems]

i was reading on subaru website that they have revised the diesel engines for the forester in the outback and have adjusted things like timing and turbo.
not only have they got better fuel economy now, claimed 6.0l/100km! which is nuts but there is a good chance if they have revised the motor they may have fixed the shudder

That brings no consolation to those of us who would have to take a ~ $20k hit upgrading to the newer model without a shudder problem.

One that note, I plugged the EGR unit back in today. The engine is back to its old ways; surging, shuddering, drinking away. Regen happened within 2 mins post warmup to operating temp suggesting there's no DPF regeneration during that stage/type of limp-home-mode.

I'm also convinced that the engine runs much leaner (air/fuel ratio) under normal conditions than in limp home mode. That would explain why it feels so soggy off boost.

To meet the EURO 5 emissions standard there's a whole lot of EGR + boost + lean running <2000rpm. Will confim this on the dyno at some stage..

Petrol, propane or diesel - the futher lean the engine is from its stoichiometric ratio for a given throttle opening (which determines volumetric efficiency) - the less mean effective torque the engine can produce for a given load of intake charge. Torque output vs injection quantity for a given load of intake charge - can be described as a curve which drops off as injection is reduced. After a point, injecting less fuel means fuel economy goes down!

To make the same amount of torque running a lean mixture we have to burn more air. In a diesel that means more boost.

The summary is;
Lower emissions = leaner mixture + exhaust gas recirculation + high pressure CRD;
Leaner mixture + EGR + high pressure CRD = less torque output, range of fuel choices decreases;
Mitigate the loss in torque by = running more boost, large throttle opening, variable valve timing;
Denser intake charge at a leaner air/fuel ratio = higher BSFC ie. more fuel has to be consumed for the same torque output and there is more waste heat.

And the point?
If there were better targetted emissions standards (or less regulation), we could have diesels sipping 20-30% less fuel, weighing 10-20% ?? less and costing significantly less to manufacture and maintain over the life of the car..

Applying all of the efficiency gains from high pressure direct injection, lightweight ceramics, chamber in piston designs without the emissions reduction / control might be just as good if not better for the environment when you look at production in its true, global sense (pollution needed to produce DPF's for example).

What a good way to spoil a potentially brilliant engine!

[pitrack_1]

I'd think Subaru already understands the problem and knows the solution, it'd be down to cost minimization at the moment. First they'll try to 'ECU flash' the problem away, and then they'll replace the hardware in the worst cases.

I could be wrong because being in limp home mode evidently disables more than one system. But it's pretty conclusive to me going from experience in tuning with EGR systems (and disabling them in performance applications). If they're open too far the engine basically chokes. If the frequency / timing is off the unit doesn't operate at the correct effective duty cycle just like any other similar electrical device. If the unit is too far open with high exhaust back pressure - there's going to be a problem. Long term the whole intake manifold will choke up with carbon and soot.

I guess the effort was to prove my earlier suspicions about Subaru's response via their service department. IE not 'lugging' the engine, using the 'revised' shift schedule, using 'high quality' fuel etc, which is all just tangential time wasting in my opinion. Sure there's valid cases where short trips cause DPF problems, but that's already in the manual i read from start to finish when i bought the car.

Bennie, i'm confident that the dealerships have no idea. If they do, they won't act until the 'mod' funding is granted from Japan. I think the more expensive the fix, the longer it's going to take. Its been close to 2 years now? I'm curious to know how well Subaru will look after owners when the 3 year warranty expires?

I'm afraid I must agree with eems. I am having the shudder, the last call (last week) to the local service department and they denied knowing of any such thing. Yet there are service bulletins, apparently?

I follow the revised shift schedule (service bulletin- the one proactive guy who gave me this moved to sales), don't lug the engine, give it good long runs, etc. I also know someone who had his EGR valve replaced last year. He had to wait weeks for it out of Japan (possible tsunami delay). I believe it may be a different EGR valve model or modified one.

I also (randomly) wonder if (since eems mentioned it) if the EGR is a PID device that, if it's not malfunctioning, there is too little hysteresis programmed leading to cycling. Or the unit's just shot/clogged.

Last shudder seemed to coincide with the end of a regen- improved response and reduced fuel usage/improved economy.

That brings no consolation to those of us who would have to take a ~ $20k hit upgrading to the newer model without a shudder problem.

My feelings and position exactly, except we don't know that the new model doesn't have the shudder problem- or something else.

And the point?
If there were better targetted emissions standards (or less regulation), we could have diesels sipping 20-30% less fuel, weighing 10-20% ?? less and costing significantly less to manufacture and maintain over the life of the car..

Applying all of the efficiency gains from high pressure direct injection, lightweight ceramics, chamber in piston designs without the emissions reduction / control might be just as good if not better for the environment when you look at production in its true, global sense (pollution needed to produce DPF's for example).

What a good way to spoil a potentially brilliant engine!

Quote from the Wikipedia EGR page: "Though engine manufacturors [sic] have refused to release details of the effect of EGR on fuel economy, the EPA regulations of 2002 that led to the introduction of cooled EGR were associated with a 3% drop in engine efficiency, bucking a trend of a .5% a year increase."

And another thing. DPFs have a finite life until they clog up with unburnable ash. I've heard 150,000km and $3000 (or 3000 Euro, even). IF this is the case, then 150,000km = 12 services @12,500km/service. $3000/12=$250 per service just to allow for DPF replacement. That is, you can effectively double the cost of each minor service. Hopefully this doesn't come to pass.

In 18 months/40,000km we have now had: 2 spurious CEL/ABS/ESC light combos, 1 dead remote key, dodgy OEM tyres (star puncture on a smooth dirt road- not even off-road) and now shudders. The external mirrors wobble, the dash/console/control lighting's inconsistent, the remote key reception is weak and inconsistent, the 'stereo' does a good impression of a 4 speaker AM radio with the tone turned down, the heater's slow in winter and the whole HVAC system is prone to hysterics. This is not the much-vaunted Japanese ruggedness/reliability I had been brought up on nor the famed Subaru engineering integrity, ruggedness and purpose of design. I suspect Subaru's slipped recently and have been trading, in that respect, on reputation. Certainly the 2010 Forester is a step down in interior material quality from our 2004 Mazda 3.

[eems]

Quote from the Wikipedia EGR page: "Though engine manufacturors [sic] have refused to release details of the effect of EGR on fuel economy, the EPA regulations of 2002 that led to the introduction of cooled EGR were associated with a 3% drop

Hi Pitrack,
Thanks for your input.

http://www.iaeng.org/publication/WCE200 ... 8-1552.pdf

Didn't have much time, but a quick google reveals a few papers. This one is well executed IMO (some aren't very conclusive).

I have a feeling the EE20 has a lot to offer in terms of fuel consumption with revised tuning - thats for sure!

Who knows how much egr there is going on (5%? %30?), and what else has been tweaked to reduce emissions at the expense of fuel consumption. Also, its possible the EGR system isn't functioning as intended by FHI due to manufacturing tolerances / fault in the unit, may be the same issue causing a shudder.

It's also plausible that EGR isn't the only fault, but a change in injection timing or characteristics of multiple injection pulses per cycle during any one part of the regen cycle (is there a pre-(post injection) warmup cycle?) is causing the shudder where the EGR unit is running out of spec?

[pitrack_1]

Eems,

I read the iaeng paper/abstract, thanks.

If the shudders are related to lots of regens, then oil dilution & its associated issues could be a problem. Even if not, the paper shows particulates increasing with increasing EGR. This would lead to more regens in any case, and therefore oil dilution anyway.

Have you looked at the oil dilution issue?

The ECU calculates a dilution ratio (see here and here) and will flash the DPF light when it reaches 10%. This can be caused by excessive regens and/or no dilution ratio reset at service.

Also have you noticed whether the vehicle appears overfilled with oil- this could be a result of service overfilling in the first place but will be exacerbated by excessive oil dilution. Geoffoz and others on the subaruforester.org forums have some very helpful info, e.g. see here.

[eems]

I came across the diesel crew blog a couple of months back, they do great work.

I hadn't read that article word for word, will look over it in detail at some point and see if it rings any bells.

Cheers

[MY11OBD]

33700km on the clock, Outback Diesel.
Past week DPF light flashing... I was due for service so booked this in today.
Told the service departement that have been getting intermittent PDF flashing all week and asked if they could check the filter blockage %.

On the report back they had 54%, and they said they had to force a manual regen back to 20%. DPF flashes have gone and car runs alot better.

Service dept also said the Flashing will come on from 60% to 85%, so not sure why mine came on at 54%?

Also noted to run a high revs for at least 20 minutes, maybe 80km @ 4th to regualry clear DPF if alot of city and stop / start traffic is being experienced.

Just a few things I found out today and thought to share.

[pitrack_1]

Service dept also said the Flashing will come on from 60% to 85%, so not sure why mine came on at 54%?

Have a look here, here too and here three.

Also noted to run a high revs for at least 20 minutes, maybe 80km @ 4th to regualry clear DPF if alot of city and stop / start traffic is being experienced.

Recommendation is now to keep the revs somewhere around 2000rpm (give or take). But this leaves you open to the dreaded shudder. Did you receive revised shift points?

On the Forester the shift points were (indicated km/h) 24, 40, 64, 72, 80. This was revised to 24, 40, 65, 85, 105. Hence asking you to do ~80km/h in 4th.

[MY11OBD]

Thanks thats a lot of info will keep an eye out.

[superroo]

My Outback Diesel is 4 months old and has the same issues that so many people are experiencing.

My question is: has anyone found a fix as this is a potentially dangerous problem, as when you loose power (when experiencing this problem) and have a truck up your backside it is really scarry!

[Falco80]

Recommendation is now to keep the revs somewhere around 2000rpm (give or take). But this leaves you open to the dreaded shudder. Did you receive revised shift points?

On the Forester the shift points were (indicated km/h) 24, 40, 64, 72, 80. This was revised to 24, 40, 65, 85, 105. Hence asking you to do ~80km/h in 4th.

I travel 200Km's on the highway for 4 or 5 days of the week and i pretty much don't use 6th gear. If i'm driving normally i upshift at 3000rpm and downshift at 2000rpm. You have to remember also that the speedo is waaaay out, as 100km/h indicated on the speedo is like 92km/h actual speed on GPS. I only drop it into 6th if i'm doing 120km/h on the speedo, which is just over 110km/h actual speed. I keep the engine spinning between 2000-3000rpm and don't have any issues. You need to rev these engines, lugging them around is not doing yourself any favours. If your in the city you need to take it for a hard fast run periodically with the engine maintaining a decent speed for a prolonged period. Sometimes i'll drive the 100km's home in 4th gear, engine doing 3000rpm's the whole way on cruise control. Economy doesn't change.

[MY11OBD]

Hi Dan, what is your averge economy?
seems though you travel quite a lot of kms each day/week.
in comparison to some you are doing 5 times more... would you think driving the car harder in say someone that uses city roads and travels
roughly 50km per day make and difference,since in city driving there is constant stop start and never much chance of being able to achieve 80km/he on 4th gear for at least 15-20mins...

[Falco80]

Hi Dan, what is your averge economy?
seems though you travel quite a lot of kms each day/week.
in comparison to some you are doing 5 times more... would you think driving the car harder in say someone that uses city roads and travels
roughly 50km per day make and difference,since in city driving there is constant stop start and never much chance of being able to achieve 80km/he on 4th gear for at least 15-20mins...

My economy over the last 57000k's averages around 6-6.5 litres per hundred. Some weeks I drive for economy and others I give it a good flogging. I don't take that figure off the vehicles readout, I calculate that from actual km's travelled each tank with the GPS (which is always around 20k's more than the trip-meter in the car) and the litres of fuel I filled up with. I use the same servo close to home and fill it to the brim everytime.

In my opinion if your in the city then this is the wrong engine for you. Whatever Subaru tells buyers, it's just to get sales and move cars out the door. If your thrashing it in the city all your doing is clogging the DPF faster and the poor old thing never gets a chance to do proper regen because of all the stop-start traffic.

[ahum]

Hey guys

My 2010 Diesel Forester has developed the shudder of doom in the last couple of months.

First trip back to the dealer I went for a drive with one of the techs and got the impression he'd seen it before. He updated the computer but that did nothing. Second trip back they said they wanted to change the glow plugs (what does that have to do with anything since all they do is assist with starting the engine) but didn't have any in stock so back again this week for that to happen.

In the mean time I have this morning unplugged what I assume was the EGR unit as per eems post. This caused the check engine and traction control warning lights to come on but the engine was smoother than ever but has limited power as the turbo won't kick in (I assume this is because the engine warning lights has put the car into limp home mode). Plugged the EGR back in and instantly back to coughing and shuddering and generally a terrible drive.

Going to tell the dealer to give me a loan car and not to bother giving mine back until it is fixed properly.

Edit: Just spoke to the dealer about getting a loan car and asked why they wanted to change the glow plugs. Short answer is they don't but need to remove them to get at the real problem and wanted spares in stock in case the got broken (apparently they are a pain in the ass to remove).

[wbj]

ahum, how many k's on the clock? Have you had any issues with the dpf?