Forrester 2.0 Boxer Diesel, why all the worry ?

[Stuartspanners]

Hi, yes I'm a newbie, on here at any rate, but have been a lifelong Subaru fan and there is not much I haven't worked on over the years. I currently run a late 2010 2.0 Forrester with the flat four Boxer Diesel engine. I am always being asked by customers how i find it and whether they should buy one? Now that's a subjective question, because we all know that every make of car has something that folk won't like about it, even those that have an opinion...... but have never actually owned one themselves ! .... My own vehicle has done nearly 90,000 miles of which i've covered around 40,000 of those both here and abroad..... Since day one of owning it, it has "knocked and rattled" from cold, ( which is why the customer got rid of it and I aquired it ) I changed the tensioner (only slghtly better) I changed the oil every 5,000 miles ( no difference ) I changed the injectors, waste of time ... I ran Slick 50 for a year, marginally quieter, or was I just kidding myself ? .....in the end though, even i stopped worrying and just used it, and guess what ? Nothing happened.....it didnt blow up.... it didnt get any worse, it didnt use any more fuel, in fact it has never let me down, and yet three years later and 40,000 miles of hard driving, it still knocks like a hammer on a block of metal for the first 5 minutes or so after start up.....then as suddenly as it came....it disappear's ....and all is silky and smooth, and quiet for the rest of the day, and continues to be as I write this .....So, whats the point of this post? Only to say that sometimes even us so called mechanical professionals can over worry something that actually isn't a worry at all.... its just accepting and living with the fact our vehicles are sometimes not as perfect as we would like them to be, be that through design or otherwise....Subaru are indeed a left field choice, not to everyones liking, they can be a strange and complex beast at the best of times....but I'm growing more and more attached to my "not perfect" mode of transport, in a normal world, engines with problems tend to start quiet and get progressively noisier as the problem increases..... with Subaru and this particular engine it simply gets quieter ! .....or is it just mine ?.... Happy driving 2018.

[savage bulldogs]

Think the early boxer diesel engines had a issue with the crank , I'm sure someone on here knows exactly what it was that was prone to failing .

I did have a 97 uk turbo that sounded horrific on cold start but once up to temp sounded fine . That was definitely piston slap and once the pistons had expanded and the engine up to temp , it sounded fine .

The 2.5 ltrs do get a bad rep too , with some standard ,unabused and well looked after engines, popping the headgaskets or suffering from ringland failure .

Will i be selling my 94 sti anytime soon ?

Nope , not a chance [emoji16]

i love my quirky retro underdog scooby to bits [emoji6]

[Stuartspanners]

My thoughts too......but surely it wouldn't last 40,000 miles would it ? I've seen that problem on a number of pre 2010 engines, but haven't actually worked on any later ones with the crank problem, that's not to say it doesent happen, I've just not come across any myself, plus it's so damn quiet once it's warmed up, and in the summer months you hardly notice it ? .....On any other diesel or petrol engine a loud knock when cold usually spells disaster, certainly i dont know of any other make I've worked on where a noise that sounds like a big end knock gets quieter the hotter it gets ! ....and certainly not one that's, still going strong 40,000 miles later ! .... as a seasoned engineer I'm baffled .....either I've been incredibly lucky, or this is a very unusual characteristic of this particular engine ? 

[Mr B]

lot of knocking and rattling all do with ecu map and calibration of injectors and sometimes heater plug and injector faults too .
Early diesels 2008/2009 worse for the crank failure, 2010 still do it but had block and crank revisions by then that made big improvement .

Why most people worry is fact injector, heater plug, crank and also dpf issues all very expensive and a painful diagnostic process .

We done a few diesel engine swaps now, I could buy 2 or 3 2008 to 2010 engine/running fault diesels a month trade if wanted as that many about.

Good one is great car but get a bad one and financial hit is high and it major kick for some buyers who went into the purchase on subarus pre diesel reputation .

 

 

 

[Stuartspanners]

Hi there, ......must be different down your neck of the woods, not so many "Pre 2008 / 2010" Foresters about up here with sensible mileage, especially ones that are not Farmer owned anyhow, and to try and find one that hasn't been a pet carrier or used off road is almost impossible, this one has only had 1 Private Owner before me and is fantastic throughout.

I'm still not worried as using it daily ...... BUT .....I'm always waiting for it to go bang in the winter as it' just knocks so loud on cold start, but as I say, I've down over 40,000 miles on top of the 46,000 that was already on it, and it never has ! ...... still as quiet as ever once warmed up ?

What I'm really looking for is someone else to say, "mine does that, it always has" ....... or..... "I know exactly what that is, change this or that" ..... trouble is, I know my way around this engine and so do a few other Subaru Techs I know, including a great Main Agent Guy who has worked on loads of them, and even he is baffled, the noise sounds incredibly like piston slap, but never heard of a Boxer Diesel suffering from that ?

[savage bulldogs]

I personally don't know much about the diesel lumps but i do know my way round the early impreza engines .

I know of several petrol turbo scoobies from classic (92) to blobeye (04) that have had piston slap for years . I'd read that the v3 97 to v4 98 were more prone to this due to the open deck type block and a change in the composite of the piston material .

I think its probably due to either incorrect oil grade , lack of service interval or lack of mechanical sympathy. I've seen a few drivers bouncing off the limiter from a cold start and with the pistons being cold , the tollerances are bigger . The exessive throttle when cold can cause bore wear and ovallity would create bigger tollerances and more noise from cold but once the pistons have expanded they take up the play (goes quiet)

My v3 uk had piston slap at 86k but i serviced it every 5k and always warmed it up /cooled it down before i used boost . I got it remapped and it done 20k before i pulled the lump out to replace it (by choice , it still ran fine ) .

As long as you dont have too much blow by when cold and let it warm up and cool down the petrol ones are fine . my friends 97 uk had piston slap at 70k . It was remapped to 320hp and now has 260k on the original engine [emoji6]

[Stuartspanners]

Therein lies the problem ....... Like yourself and others on here, I and a number of associates are aware of the older petrol engines ( 2.5 etc: both here and North America ) having suffered piston slap for whatever reason ? and yet many are still going strong miles later.......but "Not" the later Boxer Diesel's, very few people seem to know anything about them,  in fact it's hard to find private or trade individuals that even own them, let alone work on or talk about them, it's not the prone tensioner slap , nothing like that noise, and it's been replaced anyway, nor can I believe it's rod or bearings, they simply wouldn't, and couldn't, have lasted this long ? ....... This has a full Subaru history ( plus my own maintenance ) was owned by a mature sensible owner, has never towed or been off road to my knowledge? so it's not abuse or maintenance related, I would simply like to know if anyone has a 2008 / 2011 Forester with the 2.0 EE20 Boxer engine that's only noisy when cold  ........ but you try finding someone !

Still loving it though, and often get asked ......"Is that a Lexus?"

[Mr B]

A knocking noise similar big end on the diesels is normally due to injector fuelling, testing and calibration or ecu updates can help resolve it in many cases.
Some are worse cold but narmally still present when hot . It certainly not likely internal mechanical issue .

[Stuartspanners]

Yes.....I have heard that a re-calibration of injectors can sometimes make a noticable difference, I dont have the firmware to calibrate myself, and i would say it takes approx 5 minutes to quiet down once started in current  cold weather, but then it ticks over as per any diesel and drives absolutely fine, .....sounds like a loud metallic crack crack crack sound when started though? Totally appreciate that as with any vehicle, intermittent rattles, knocks, misfires etc:  are the worst kind of faults to accurately diagnose ! .....thanks for all the replys, if anyone on here owns one of this year (2010 /11 or later and has similar noises when starting from cold ? Then by all means get in touch ...... 

[Clogwork_orange]

Greetings

I have only recently become the owner of a 2010 Subaru Forester Diesel (115,000 miles). It is a bit of a Jekyll and Hyde.  

 

On cold mornings the car would run rough for a couple of miles and make a loud clattering noise when accelerating. The clattering seemed to be worst in the 1500 -1700 rpm range and would disappear when I came off the accelerator. As soon as the heating/airco kicked in (after 1~2 miles), the roughness would subside and the clattering would be less noticeable; once the blue engine cold light extinguished, the engine would run smoothly and the clattering would either disappear or be barely noticeable.

 

Under warranty the garage has replaced the glow plugs and cleaned the air system. Plus quite a bit of fuel system cleaner has gone through. The rough running has more or less disappeared and the clattering is a lot less. I drove it on 200-miles round trip (motorway) and it was sweet; however, the clattering has not gone altogether. When clattering, the belt tensioner moves about, but I think this is a symptom rather than the cause. Somehow I have the suspicion that the injector/ECU timing is wrong when cold and readjusts when warm.

 

Despite its foibles I still like the car though…

[MarkJoseph]

On 2/1/2018 at 9:05 AM, Stuartspanners said:

Therein lies the problem ....... Like yourself and others on here, I and a number of associates are aware of the older petrol engines ( 2.5 etc: both here and North America ) having suffered piston slap for whatever reason ? and yet many are still going strong miles later.......but "Not" the later Boxer Diesel's, very few people seem to know anything about them,  in fact it's hard to find private or trade individuals that even own them, let alone work on or talk about them, it's not the prone tensioner slap , nothing like that noise, and it's been replaced anyway, nor can I believe it's rod or bearings, they simply wouldn't, and couldn't, have lasted this long ? ....... This has a full Subaru history ( plus my own maintenance ) was owned by a mature sensible owner, has never towed or been off road to my knowledge? so it's not abuse or maintenance related, I would simply like to know if anyone has a 2008 / 2011 Forester with the 2.0 EE20 Boxer engine that's only noisy when cold  ........ but you try finding someone !

Still loving it though, and often get asked ......"Is that a Lexus?"

My Subaru 2010 diesel now 370,000kms. Makes that intense noise. Always has. Then later it's quiet. Oil change every 10,000kms. Never an issue...ever.  Most brilliant vehicle for many reasons. 5.0 ltr/100kms. Incredible. Always. 

[Mapforester]

Hello everyone from Turkey:

I bought my Forester  model year 2009 185000 km on clock 2 months ago. He have some problems that i solved

- new Battery,

- new flywheel,

- new timing chain,

- adjusting valves.

He is now go so clear when engine is hot. But in cold blue light on, he is very noisy and rattles.

Mechanics say that all early diesel engines have same block and crankshaft problem. They say i will have to change shortblock sooner or later.

Yeah it could. But i love my forester. Like "stuartspanners" i will see how long he goes without crankshaft failure. 

İ hope he doesnt fails. But for now: when engine is hot he is smooth with 5 liter per kilometer out of traffic. 

By the way stuart if you can help me about some tips or etc about my car i would be thankfull.

This is how he sounds before and after chain and valve.

https://youtu.be/SN84JBggCfY

Best regards.

 

[Fozjohn]

Hi, I've had my 2011 EE20 for a few months and I get a clattering noise when feathering the throttle whilst driving. If it were a petrol engine then I could only describe the noise as loud pinking sound. Surely this is not normal. I was also told to check EGR valve which I will this weekend. My forester has done almost 92k miles. Any more ideas as to what noise is would be great...

[Iain C]

On 6/5/2020 at 3:31 PM, Fozjohn said:

Hi, I've had my 2011 EE20 for a few months and I get a clattering noise when feathering the throttle whilst driving. If it were a petrol engine then I could only describe the noise as loud pinking sound. Surely this is not normal. I was also told to check EGR valve which I will this weekend. My forester has done almost 92k miles. Any more ideas as to what noise is would be great...

I've owned a 2008 diesel Outback now with 123,000 miles on it for just over seven years; as another member mentioned a few posts earlier, my opinion is also that the injector timing is out when the engine is cold especially in winter conditions.  Car runs like a sewing machine once properly warmed up.  I've also tried Slick 50, premium diesel, Millers diesel additive etc but none have made any difference as far as I can tell.

[MackL98]

We have a 2008 130k mile diesel. A bit rattly when cold, but after a warmup its fine and smooth. I use mobil 1 ESP 5w30 every 6k miles or so. The only major thing its had in its life is a clutch and latterly a dual mass flywheel (symptom, ..can't get the gears when you want them).

[Johnc]

Hi everyone I've got a 2010 forester and I'm after a bit of advice I had a bit of a meltdown with it and had the engine reconed new crank etc now 5000 miles later its got a knock and with the lockdown I've missed the warranty I've just dropped the sump off and no bit's of metal in there so that had me and I sieved the oil and found some bits of plastic so I was wondering if anyone has any idea what they might be 

Edited July 29, 2020 by Johnc
Adding pictures

[A Lamb]

I have a 2015 Forester diesel and it rattles until the blue light turns off, it started doing it after it had been in for a safety recall and I think they did a software upgrade, anyway that  was two years ago. The car has done 43000 miles with no faults ( done service myself) 

[Subaru euro 4]

On 3/31/2018 at 10:18 PM, Clogwork_orange said:

Greetings

I have only recently become the owner of a 2010 Subaru Forester Diesel (115,000 miles). It is a bit of a Jekyll and Hyde.  

 

On cold mornings the car would run rough for a couple of miles and make a loud clattering noise when accelerating. The clattering seemed to be worst in the 1500 -1700 rpm range and would disappear when I came off the accelerator. As soon as the heating/airco kicked in (after 1~2 miles), the roughness would subside and the clattering would be less noticeable; once the blue engine cold light extinguished, the engine would run smoothly and the clattering would either disappear or be barely noticeable.

 

Under warranty the garage has replaced the glow plugs and cleaned the air system. Plus quite a bit of fuel system cleaner has gone through. The rough running has more or less disappeared and the clattering is a lot less. I drove it on 200-miles round trip (motorway) and it was sweet; however, the clattering has not gone altogether. When clattering, the belt tensioner moves about, but I think this is a symptom rather than the cause. Somehow I have the suspicion that the injector/ECU timing is wrong when cold and readjusts when warm.

 

Despite its foibles I still like the car though…

The movement in the belt tensioner is more than likely due to the alternator clutch pulley gradually seizing . Easy and cheap to replace. 

[Subaru euro 4]

On 1/31/2018 at 1:49 PM, Stuartspanners said:

Hi there, ......must be different down your neck of the woods, not so many "Pre 2008 / 2010" Foresters about up here with sensible mileage, especially ones that are not Farmer owned anyhow, and to try and find one that hasn't been a pet carrier or used off road is almost impossible, this one has only had 1 Private Owner before me and is fantastic throughout.

I'm still not worried as using it daily ...... BUT .....I'm always waiting for it to go bang in the winter as it' just knocks so loud on cold start, but as I say, I've down over 40,000 miles on top of the 46,000 that was already on it, and it never has ! ...... still as quiet as ever once warmed up ?

What I'm really looking for is someone else to say, "mine does that, it always has" ....... or..... "I know exactly what that is, change this or that" ..... trouble is, I know my way around this engine and so do a few other Subaru Techs I know, including a great Main Agent Guy who has worked on loads of them, and even he is baffled, the noise sounds incredibly like piston slap, but never heard of a Boxer Diesel suffering from that ?

I’ve exactly the same experience. I have a euro4 2009 version. Yes it’s loud when cold by once slightly warm it’s quiet and smooth. Now past 100000 miles, I change the oil and filter every 6000 miles, it just keeps on going. I bought it on 62000 a few years back and I love it. Never lets me down. Oil dilution reset every oil change, no issues whatsoever.