Subaru Forester Owners Forum banner
  • The "Garage" feature is for images of YOUR VEHICLE/S only - no blanks or other unrelated images please, thanks

2010 - Pitrack_1's Saga: DPF regens vs performance & economy loss - Update

235K views 501 replies 52 participants last post by  Alternate  
#1 ·
Just to recap: I've been skiting on for years now about how during my apparent DPF regen events there is a large loss of performance and economy. recently I've noticed there are far more of them in the ~20-30C range. In the past couple of days, the events have occurred at distances of 70, 47 and 47km apart in suburban highway running and usually run for 10km or so.

Well, Yippee! I've had a couple of outcomes today. They pose more questions than answers currently, but progress is being made.

1) Data has been logged by a Subaru dealer for sending to Subaru today. It didn't happen until I was on the way back to the dealership, however I was able to have the event logged and demonstrate the performance deficit to the service manager. They reckon they'll get back to me, in the eternal words of Con the Fruiterer (old Aussie pop culture reference), "A cuppla days."

2) Typically the apparent regen initiated itself just before I arrived at work today (like, turning into the driveway) and before going to the dealer nearby. After some teeth gnashing, I drove around a bit and logged some of my own basic OBD-II data. The throttle position variable does indeed vary downwards under acceleration during this event, reverting to 78.43 or 78.82% upon release of accelerator. I have not logged it varying outside the event.

3a) Note the terms "apparent" and "event". One thing the service manager did tell me was the car was not logging it as a DPF regen- the last DPF regen logged was some ~670km ago.

3b) The service manager said he hasn't seen anything like this before. He didn't seem unhappy with my driving style and the dealership is familiar and experienced with a few diesel engine issues now. I hope Subaru don't impound the car for further testing!

More to come when results are in. I wonder what the thing's up to or thinks it's up to?
 
Save
#467 ·
I see it in the CSV file i uploaded to torque but it doesnt show in the selectable pid list in torque. Is it possible there is something missing from the string in the CSV file ? If i manually input the values via the torque add pid section it doesnt work. cheers for the reply.
 
#472 ·
Ive rechecked the csv file and removed and added it to torque it just wont show. What do I need to add to torque from the csv string ? Is it possible that the 2011 diesel has a different code for this function ?
 
#474 ·
Hello,

I just decided to sold my Forester diesel after almost 8 years. I decided to switch to Toyota RAV4 Hybrid AWD. It was really tough decision as I really want to stay with Subaru. I can forget about all DPF issues and fuel efficiency is better as Forester. Also car dynamic is much better as anything what Subaru can actually offer in the EU. Even new Outback is slower with worse efficiency and much more expensive. Only weak point Toyota has is AWD made via electric rear motor. But I'm not off-road driver, so maybe I didn't see any difference, hopefully. So I wish you all the best with your diesel Subaru cars.
 
Save
#475 ·
Is that the new RAV4 Plug-in hybrid? My parents has a 2016 RAV4 regular hybrid and fuel consumption on that is higher than on my Forester diesel. My dad is a little disappointed by it, but they don't really drive that much so it isn't a big deal.

I haven't had any DPF issues as well, but see that many does. I must have gotten a good one!
 
#476 ·
No it's regular hybrid but 2021 model. I tested fuel consumption this weekend at 200km trip to the mountains and I get better fuel consumption as on my diesel Forester. And I made that trip at the same time, 2 hours. So I'm quite satisfied.

Plug-in hybrid is way too expensive for me. It costs about 15000 eur more.
 
Save
#477 ·
congrats on your purchase.
My wife drives a 2010 Prius and the more I get to drive it, the more sense it makes as a means of transport. No engine idle while in traffic jams, no engine while decelerating or braking, no engine while moving slow. If you pay attention to your driving style and use as much electric as possible, you can really accheive impressive consumption numbers. Of course nothings comes close to Subaru AWD, but if you dont have half a meter of snow every winter, I dont see thats an issue.
 
#478 ·
My impreza diesel is still going strong. No dpf issues in the last 15k km. Last regen was 3500km ago, and that was the automatic regen that is beeing done at 6500km.
now the car has over 190K km. oil changes at 10K. Subaru dealer has been impressed with the performance of the dpf at the last oil change. Told me that he never saw that many km without regen. :)
 
#479 ·
It has been a while (actually, longtime) since I have been here whilst I dealt with a few personal issues.

Currently I still have the Forester. It doesn't get driven much but goes out for a shortish (due COVID-19) run once every couple of weeks to keep it running. I've got some diesel stabiliser/ system cleaner in the tank to protect it and assist with DPF cleanliness.

Car has actually been running quite well. All works, only issue is clutch shudder when driven after sitting for a week or two. I'm assuming some slight oil contamination of the clutch surfaces- I guess maybe a slight rear main seal leak or similar.
Given it is winter the DPF regen issue has been (predictably) behaving itself. I also have an additive in the tank to protect the fuel from going stale and to assist regen.

Did my own oil change this time- somewhat overdue on time- very easy, you just need the 12(?)mm allen head for the drain bolt. Car's high enough that I don't even have to jack it up to squeeze under to get to the drain bolt. When I did, I had a quick look at the front suspension, did note a cracked boot on one of the ball joints/tie rod ends/drop links/something so that may need to be attended to in the future. There were some other oil leaks/seepage around the engine too, but not enough to drip. I reset oil dilution following oil change of course.

Now before I did the oil change I initiated a forced regen which took approx 10-15 mins to run its course. To my slight consternation, the first 5 mins or so a reasonable amount of blue/grey smoke was emitted- not clouds, but enough to visibly drift up and over the fence in the dusk light. In my opinion it smelt somewhat of oil/diesel- which may be expected under regen conditions of course. The exhaust note was somewhat uneven with what sounded like slight intermittent/non-regular misfiring. After the first 5 mins or so the smoke gradually disappeared and remainder of the forced regen completed without visible smoke. I have not seen this smoke on a forced regen before, certainly not the amount I saw this time. If the turbo or another component was failing, I would've expected the smoke to remain constant. I'm just wondering if there has been some oil contamination of the DPF/exhaust system over time from a slight oil leak. If anyone has any opinion on what might have caused it, feel free to chip in.

Taking the car for a quick run afterwards and performance/driveability was good, sharp/snappy, no flat spots or misbehaviours, actually reminded me of when it was new. As I drive it only a few 1000 klms a year, if I can afford it I might hang on to it for a bit of fun- camping with my daughter was the main aim. COVID-19 amongst other things has seen to preventing that and no doubt will so long as I hold the car- but as I am stubborn I will hold the car in defiance of life and make it continue to stop me. :confused:

I'll catch up with the thread and forum if I can when I can. Thanks to all who have posted above.
 
#480 ·
Hello guys, it´s been around 5 months since I had my oil changed and my PDF cleaned and reset. The regens cicle has improved a lot. Last winter (january-march) The car was doing regens every 60-120 km on the highway. With the same driving routines and roads, I am now doing 900km on the highway without regens and the car then regens if I do some short and frequent trips (i.e. short trips in the mountains). I have also obtained that with 35-40 celsius degrees on the road (I live in Spain). It seems then that my DPF needed a clean and reset. Now works great. Regard
 
#482 ·
Well the car has been behaving since the oil change and forced regen... at least for the little I've been driving under lockdown recently. As my personal situation also seems to have stabilised somewhat recently I think I'll change my signature re: the forester going. That should provoke things! :p
 
#483 ·
F-up Forester strikes again
Well, just an update. I deceded to go on a bit of a trip down the coast with my daughter.I've been waiting for this for years due to COVID. So I moved the cage (cargo barrier) forward to behind the front seats. Now we have oodles of space to throw stuff in, and could sleep there if necessary. We didn't even fill the floor area much less stack stuff up!

Tested the car on the drive out of Canberra, everything was ok. In particular I tested the clutch as I knew it was getting a bit soft. All fine accel in 6th up the hill out of Canberra.Car ran fine all the way down towards Pambula/Merimbula in warmish weather- even my daughter thought so!

However it was down the coast that the troubles started. On a day trip down to Eden, upon return towards Pambula on the Princes Hwy, on an uphill under cruise in 5th the clutch suddenly let go. It rapidly got worse after that. Called the NRMA, who tested it- it would stall ok- and said it was simply worn. Fair enough after 225k km incl city driving- can be considered a wear item. But a ginger test drive in the morning showed the revs would flare easily even in 3rd now, and 2nd under moderate acceleration. Much worse in a day or so of driving around the area- perhaps ~200km. No way it was getting back up any hill much less 600m climb & 300km back to Canberra. We were staying 30km inland from Pambula, the main mechanic centre nearby. So it was a ginger run down from Wyndham to Pambula- all downhill- to get to a mechanic. Of course this was a Friday so we had to wait out the weekend, this was coupled with a sick (by this stage) daughter. Luckily I was able to organise a lift back to Canberra- funnily enough, in a manual petrol Forester of the same model. There are heaps of Foresters around that area, so at least the mechanics are familiar with them.

At least car was OK on the flat at Pambula so got to go around to the beach for a day or so.

So it will almost certainly be a new clutch, expensive in these things with the dual mass flywheel. Wouldn't have minded if it gave some warning, or let go more gradually so I could have nursed it back to Canberra. But car is stuck in Pambula and won't be looked at until after Jan 4th at earliest and this issue occured over a week ago now...

Also regens all over the place, did achieve a ~250km regen distance on the way down, however several very short (~50km) regens in between whilst babying the clutch.

And the reverse light switch is playing up. Not nice reversing in the country dark without reverse lights. These type of smaller niggling issues worry me, they shouldn't/woundn't/don't happen on a Japanese car and point to cheapening of component sourcing (other have happened - the neutral/gear selection switch, rear diff temp sensor, key fob, etc.) on this model.

$1k planned holiday will turn into $4k now I suspect. At least my daughter had fun (even through the tummy upset)

I do wish to persist with the car because with the rear cargo area now with the barrier behind the front seats it is an ideal cargo/holiday hauler- esp as it is set up with driving lights, weathershields, cargo mats, etc.
 
#485 ·
Thanks! Now this worries me too, because I am at 220k km. on normal driving clutch grabs quite early, but when there is a load on the car, like trying to get on a curb, or recently - manuvering through deep snow, the clutch really grabs at the very end of pedal stroke and that is accompanied with the magnificient smell of burning clutch..

just checked, clutch kit and flywheel are around 650 Euros for Sachs and Luk kits, so not that big of a deal.
 
#486 ·
@DieselForry,
That's a similar situation to mine. First sign is a clutch that grabs high, especially under a load. That clutch burning smell is something special, isn't it! Great for removing tailgaters- slip the clutch a bit on takeoff, then watch them drop back and change lanes :p

Note my clutch has had city driving plus some abuse. Country driving and/or better use may see yours last longer.

Oh and look out for your centre diff if it hasn't already gone.

Having said that I think the clutch is too weak for the job in any case. If I revved the engine the car would never stall in third- simply sit there revving the engine with the clutch burning out.
 
Save
#487 ·
"A fool and his money are soon parted."

Further update to the clutch saga. I got the car back on the weekend. ~$2750 for the clutch replacement. At least it's an Exedy DMF unit and should outlast the rest of the car.

I couldn't organise myself to get a lift down and have the car ready at the same time, so I ended up catching a bus down on the weekend to meet someone who'd collected the key for me...forgetting I had a second key and could've organised for the other key to be simply locked in the vehicle,

Between those I think I satisfy both parts of the quote.

At least the clutch works nicely now...and I'll post pics of the old clutch if I get a chance (saved the parts). Weighs more than I expected, Sachs brand...who said Subarus are Japanese? Didn't look at driven plate yet, quick look at flywheel shows 'hotspots' like the NRMA man said there'd be.
 
Save
#489 ·
Oh yes, pleasure to read some good news for a change :D
I wonder how much the Exedy kit was?

My favourite car parts store doesn't show Exedy, but show SACHS- 320€ for DMF and two options for clutch kit 150€ and 220€
The more expensive one is "reinforced" (SACHS 3000 950 066)

Sachs brand...who said Subarus are Japanese?
Well, last week I was a victim of a split intercooler pipe elbow and it also is made in Germany. Noticed oily residue, while changing oil. Replaced that with aftermarket "Gates" brand. Luckily didn't run in any DPF problems.
with warm (~28-30C) weather- EGT was up and DPF diff press was low
You mean EGR was closed? I wonder why..
 
#488 ·
And further to the clutch saga...and DPF regens...

Car had been regenerating at short distances prior to clutch replacement, 40-60km due to running about gingerly with slipping clutch likely resulting in lots of EGR.

Had to then drive home from the coast (Merimbula) to Canberra (after a day pottering around the coast- beaches closed due to tsunami warning after Tonga eruption; weather was cloudy and sea was messy/choppy&discoloured anyway). So put diesel in and added Penrite DPF cleaner regen additive. Prompt regen, (prompted by 'testing' the new clutch :D) then next regen after approx 80km at base of Brown Mtn and proceeded all the way up the hill (I think longer than normal). Brown Mtn was socked in with drizzle and cloud, down to ~20m vis, but I had a clear run all the way up and I think this climb, albeit at low speed but lots of heavy throttle & climbing did the regen good. When I got to the top and the regen finished, the car then proceeded to drive with 0% EGR all the way back to Canberra. In this case I racked up ~160km for 8% soot, even with warm (~28-30C) weather- EGT was up and DPF diff press was low. Once I hit the Canberra zone and reduced to 80-90km/h driving- suddenly EGR kicked in and quickly the soot climbed into the 30-40% by the time I got home another 20km later- EGT was down and DPF diff pressure was up, albeit not too much.

Car drove well all the way- engine smooth, no stutter or hesitations, smooth good accel. No other issues and everything worked- except one thing- the revese lights don't work now at all. Fuel economy was excellent- showing approx 4.8l/100km post-regen (prob means 5.2-5.4l/100km) but that is as good as, if not better than, the car has ever got at 100km/h. Clutch- wouldn't know it was new- smooth uptake, light clutch action (again finally!), consistent action, no shudders, no grabbing, no noises, etc...
...AND NO SLIPPING! :cool:
 
Save
#491 · (Edited)
Quick update...it's been a while.

Car driven intermittently nowadays, at 226k km. Will prob only do 5k km in a year, if that. It's been running well since the clutch replacement, no issues. Did my own oil change, now that was easy...didn't even have to jack the car up, just went straight under! The diesel additive seems to be helping with regen distances and general engine smoothness/performance and economy. I'm averaging about 5.8l/100km, as good as it every got. I think there was some leakage through the rear main seal, since that was replaced with the clutch there's been no shudder esp after a cold start (when any leaking might've got onto things). Currently at ~410k since last regen and not quite near it yet...although DPF diff pressure is behaving differently to previously, higher at cold temps and lower at hot...reverse of previous behaviour! :oops:

I even took it on a drive up to Sydney and back to try to break it, it ran faultlessly (with good fuel economy) and has been fine since.

Main non-functioning item at the moment is the washer nozzle in front of the driver...clogged with something. Wire strands didn't clear it out either. Oh, and the dicky reverse lights (gearbox switch).
 
Save
#493 ·
Hey Pitrack,
Thanks for your writeup. I purchased an SH 2010 Forester about a year ago for the Mrs who was losing her work car and going on mat leave.
We had a glow plug go pretty quickly (which shorted the fuse). I had to take the car in to get a new FOB for it, so I asked the mechanics to take a look at this while they were there.
They just ended up unplugging the glowplug, saying "this is QLD, barely any need for them here". Shortly after another one went, so I just unplugged that too.
Since then we've had a few DPF issues, with it clogging up. I've just been removing the unit and giving it a cleanout, and that's fine, but I've since learnt that the car uses the glowplugs to achieve burnoff temps during a regen. This would explain my issue I reckon. Anyway, I ordered some plugs and have popped the first one out, but they look quite different, and I can't get the new ones started (thread looks different too). Just wondering if you know what plugs you ended up going with.

New and old plugs pictured.
I purchased them from ebay. The listing is pretty confident they should be right. eBay page
Image
 
#494 ·
We had a glow plug go pretty quickly (which shorted the fuse)....so I asked the mechanics to take a look at this while they were there.
They just ended up unplugging the glowplug...Shortly after another one went, so I just unplugged that too.
I simply unplugged all mine and left it at that.

Since then we've had a few DPF issues, with it clogging up. I've just been removing the unit and giving it a cleanout, and that's fine, but I've since learnt that the car uses the glowplugs to achieve burnoff temps during a regen. This would explain my issue I reckon.
I haven't notice it using the glow plugs for DPF regens. I monitor my car and it doesn't show the glow plugs on during a regen. However they are used during the warm up, they turn off (I think) at 45C indicated coolant temp. So I'm likely generating more soot when cold.

Anyway, I ordered some plugs and have popped the first one out, but they look quite different, and I can't get the new ones started (thread looks different too). Just wondering if you know what plugs you ended up going with.
I haven't! Left the old ones in there, disconnected. Runs fine! :)

Of course the online people would say they would fit- they're collecting the money and not test-fitting them!

Those do look different. It's quite critical to get the right model no. for the year as they changed them around. The electrical parameters (and temps) may also be different. If you can't look it up exactly (and I think there was a Dubai based crowd that may have been able to return the correct part numbers- I think they were called "partsouk" or similar) it may be best to run to your local Repco/Autobarn and get the right ones. Moreso because if they don't fit, you can take them back.

Be careful fitting new ones- get the right torque, they're fragile and so is your engine's Aluminium head!

I had to take the car in to get a new FOB for it,
Those *#^$% fobs! If another old one goes, pop it open and have a look at the solder joints. It's usually a bad one (or more), generally around the battery terminal connectors if I remember rightly. Fix that and the fob usually works again.
 
Save
#495 ·
Just an update,

Infrequent Forester driving (and infrequent checking of this site) nowadays. Last regen dist ~550km, very respectable so not even that's playing up at the moment. Dare I hope the issue is currently solved for some reason? Or is it just its standard winter good behaviour???

Everything else running fine, more or less. Take it out once or twice a month, generally when the weather is quite bad (lots of rain). Even had to 'ford a pond' which had formed in the left hand turning lane at the intersection just outside work last week- good thing it was the Forester and not my Mazda 3, must've been 20-30cm of water. Just drove through slowily in 1st keeping the car moving, luckily the left-hand lane I was turning into was empty of cars...because it was full of water! :)
 
#496 ·
Gday @pitrack_1 !!!

Thanks for keeping the forum alive !! I have read every post from the start !!

Looking for your wisdom on the matter. Details are as follows:
Bought the 2012 Forester Diesel as the 2nd owner in March 2022 with 294,000km on it (auction). Now the odometer showing 305,000km driving Melbourne Metro with not a lot of sustained 70km/h to my liking.
It has been driven mainly in regional/country VIC by the 1st owner.
Seems like the DPF is cooked. All the classic signs of it showing plenty of REGENs assuming that it may/may not have had a DPF replacement.

Option 1: Get the Diesel taken off my hands for whatever price in current state. (Maybe wrecker?)
Option 2: Spend $2.8K for the mechanic to slap on a new DPF and maybe sell it?
Option 3: Spend $2.8K on the DPF and keep it for road trips?

The question to you given what you know now about Subaru Diesel, what would make sense? Again, the options are just options. I would appreciate someone with your experience to weigh in.

Cheers
 
#500 ·
Harrumph! Hope you consider a couple of months soon. That's about what I drive the vehicle nowadays. As you can tell, I'm getting grumpy in my not-so-old days... I'm a precocious grumpy old man! :p

Option 1: Get the Diesel taken off my hands for whatever price in current state. (Maybe wrecker?)
Option 2: Spend $2.8K for the mechanic to slap on a new DPF and maybe sell it?
Option 3: Spend $2.8K on the DPF and keep it for road trips?
Turbosage, don't know if you're still here or still have the issue. In my opinion:
0) These vehicles are unhappy under city running conditions.
1) DPF likely getting towards end of life.However proper diagnosis is essential, get someone to look at any codes, the regen count, ash and soot loads,pressures and how the engine is running. If the DPF got replaced, the ECU should have been told and the DPF counter should have reset, so the ash should be low and I think the regen total also low (I think that gets reset too, but not sure, would need to check my car).
2) Get the DPF cleaned unless it has been damaged is a good option and I would pursue that first. Keeping it for road trips is a good option, that's what I do with mine.
3) At that many klms, perhaps consider a replacement vehicle, although the country klms should have been good.
4) During the pandemic the price of these vehicles was quite high, not sure if they still are given diesel's price currently. It may be worth investigating a private sale, you may be surprised- have a look at gumtree.
5) If you haven't had a MIL (Malfunction Indicator Light) yet, check distance since last MIL - should be a parameter for that. If it's from just before you bought the car...I'm cynical, possibly the original owner was told to get rid of it due to pending issues.
6) I have used an additive that seems to have improved my DPF regen distances. The penrite DPF cleaner can help, and I use the fuel doctor diesel fuel additive, this certainly seems to help with the DPF regen distance, smoother running and better fuel economy.
 
  • Like
Reactions: Kevin
Save
You have insufficient privileges to reply here.