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Considering a Forester diesel


scandalxk
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Hi All,

I need a car for work, which will take me several hundred miles up the motorway in reasonable comfort and economy, then a few miles up forest tracks and construction site access tracks, some of them moderately steep, rough or slippery.  My budget is up to about £7k, and I like diesels for the economy and reliability (my current Skoda Octavia has just clicked over 200k miles).

I was considering a Honda CRV (the 2007-on model) on the basis of reliability, economy, and the fact that the auto-AWD is mechanical, not electronic.  (I am not looking for extreme 4x4 ability, I have to emphasise.  Ground clearance is as important as 4x4.  I know that the CRV is not exactly a farmer's wagon.)

Then someone gave me a lift in a recent Forester diesel, and I was very impressed.  He loves it.  According to the specs it should be more economical than the Honda, have better off-road capability, and have all the few accessories I need - in particular cruise control for the (Scottish) motorways and the average speed cameras on the A9.  I could afford a 2008-9 diesel model with about 80k on the clock, but not much newer than that...

...and then I started reading around and I keep hearing about DPFs, DMFs, "injector relearning" (whatever that is) and broken cranks.  Oh, and I noticed that there are very few 2008-13 Forester diesels on Autotrader with more than 100k miles on the clock!  So here are some questions:

1.    DPF:  How likely is it to fail?  What are the implications of failure?  How much does a replacement typically cost, fitted, at a main dealer or independent?  Can you expect it to last as long as the original?  Can you get used ones, and if so it is worth while?  Is it practical to remove it completely (could it be detected on MoT)?

2.    DMF:  How likely is it to fail?  What are the implications of failure?  How much does a replacement cos?  Can you get a non-dual mass replacement?  Does failure cause any other damage to the car?

3.    What is "injector relearning" and why is it a problem?

4.    Broken cranks:  I think I read somewhere (I can't find it now) that this problem stemmed from poorly written engine management firmware that fed too much torque to the crank, and that the cure was revised firmware.  Is this true, does the revised firmware actually cure the problem, and how can I check whether a given car has the revision?

And I suppose finally: If not a Forester, then what?  Back to the CRV?

Sorry about writing an essay for my first post!  All advice gratefully received.

Many thanks.

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My mum has a 2012 diesel forester, and she absolutely loves it! She's owned it from new and it's never missed a beat. There have been times when i've driven it and it is such a comfy car compared to other diesel cars in it's class...

As for most of the issues noted I can't help as she only has 35k on the clock and as stated hasn't had any issues yet.

I'll try my best to explain injector coding though: Diesel injectors are made to very strict tolerances, and after production every single one is tested for fuel output. The code stamped on the top is linked to the fuel output of that injector. Your engine learns the fuel outputs (codes) of your injectors so it is vital to replace the injectors with ones of the same code, then make the car 'learn' them again (to ov

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6 hours ago, HawkeyeLawrence said:

My mum has a 2012 diesel forester, and she absolutely loves it! She's owned it from new and it's never missed a beat. There have been times when i've driven it and it is such a comfy car compared to other diesel cars in it's class...

As for most of the issues noted I can't help as she only has 35k on the clock and as stated hasn't had any issues yet.

I'll try my best to explain injector coding though: Diesel injectors are made to very strict tolerances, and after production every single one is tested for fuel output. The code stamped on the top is linked to the fuel output of that injector. Your engine learns the fuel outputs (codes) of your injectors so it is vital to replace the injectors with ones of the same code, then make the car 'learn' them again (to ov

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Thanks very much for that clear explanation, Hawkeye.

You're right, the fact that your mum's car only has 35k on the clock means it is not really useful for my purposes.  I can't afford one that new; as I wrote, I think I could get an early one with 80 - 100k on the clock, and as I can find only a few with over 100k, I do wonder whether that is the limit of their expected life!

Thanks again.

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10 minutes ago, Tidgy said:

Way things are going personally i'd stay well clear of diesels.

Yes.  I like diesels but I can't see the price of diesel fuel going anywhere but up in the next few years (relative to petrol).  Noises from the government recently seem to be designed to prepare the ground for some future action.  But a cheap diesel car may still be a good bet for a couple more years.  I certainly would not buy a new one.

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27 minutes ago, scandalxk said:

Yes.  I like diesels but I can't see the price of diesel fuel going anywhere but up in the next few years (relative to petrol).  Noises from the government recently seem to be designed to prepare the ground for some future action.  But a cheap diesel car may still be a good bet for a couple more years.  I certainly would not buy a new one.

They are already banned in certain cities so its only a matter of time before the tax them to buggery to stop people buying them. Also they only make financial sense if your doing over 18k a year anyway

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@scandalxk there's some useful stuff in this thread about the diesels.  I had DPF issues on my last car, and they wanted £750 for a new unit - that was a VAG 1.9 TDi.

Surely your budget can get you a tidy enough Octavia Scout? since your last one has been dependable!

 

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6 minutes ago, W444AJD said:

@scandalxk there's some useful stuff in this thread about the diesels.  I had DPF issues on my last car, and they wanted £750 for a new unit - that was a VAG 1.9 TDi.

Surely your budget can get you a tidy enough Octavia Scout? since your last one has been dependable!

 

Thanks W444AJD.  Yes, I've seen that thread - including your contribution - and the one thing it did not give was the cost of a DPF.  I'm not particularly frightened by big bills: I replaced the camshaft on my Skoda at 180k, which my mechanic thought was mad, but it has paid off! I assume that a Subaru DPF would be very roughly the same as an Audi...?

As for the Octavia Scout, yes, that is certainly on the list.  Not so good off road as the Forester, and in particular less ground clearance, but still a very good car.  Better than a Yeti, which has a much smaller boot.  According to a friend, who has owned two Scouts, the DPF on the Scout will almost certainly fail at around 160k.  My current Octavia is pre-DPF and is still going strong at 201k.  The big, big problem with my standard Octavia is extremely poor ground clearance under the sump, which makes even good-quality forest tracks difficult.

Thanks again.

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A DPF is a consumable part.  The time between replacement depends on how the car is driven - budget for £500-1000 at some point after 50,000 miles and you will be prepared.

A colleague just had a new one on a Mondeo (£500) after 130,000 mainly motorway miles (car is almost 6 years old), I've known others fail at 50-60,000 - largely 'pootle round town' motors purchased by those who want to save a few quid on fuel, forgetting they are killing the expensive DPF very quickly!

 

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51 minutes ago, daveyjp said:

A DPF is a consumable part.  The time between replacement depends on how the car is driven - budget for £500-1000 at some point after 50,000 miles and you will be prepared.

A colleague just had a new one on a Mondeo (£500) after 130,000 mainly motorway miles (car is almost 6 years old), I've known others fail at 50-60,000 - largely 'pootle round town' motors purchased by those who want to save a few quid on fuel, forgetting they are killing the expensive DPF very quickly!

 

Thanks daveyjp.  I think the question of whether you regard the DPF and DMF as consumables or as "WTF???!!!" shockers is crucial.  If you regard the DPF as a consumable that WILL need replacement, then you can include it in your budget calculations and work out whether the other benefits of the Forester over (say) a Honda CRV are still worth taking on board.

So I think I need to test drive a CRV and a Forester (and maybe a Scout, maybe even a Kia Sorento), find out the DPF (and DMF) outlook and costs of each, do some sums which include some assumptions about the price movements of diesel relative to petrol over the next few years, and ask the vendors some detailed and searching questions about exactly how their car has been driven: down to the shops and back every day on a cold engine, or up and down the motorway to Scotland?

Thanks again.

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Just my two pence: at work 90% of DPF problems we see are blockages, NOT failures... Most people see something like 'DPF efficiency below threshold' and assume it needs replacing- not most of the time! We rejuvenate them with the lexus diesels we see- just unbolt the downpipe from the turbo, give it 4 squirts of the cleaner, 4 squirts of flushing concentrate, bolt back together and drive in 3rd gear at 50mph for a few mins in rejuvenation mode. We charge customers £800 for this (as opposed to £2k+ for a new DPF... if you can get hold of the flushing concentrate and rejuvenation procedure for your particular model, you're looking at a couple of hundred quid max!

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I know that some DPFs are a hell of a lot easier to clean out than others.  Some of them need cutting and re-welding for example.  I was quoted around £750 for replacement DPF, so not up at £2k, but that was an Audi A3 so I dont know how Subaru ones compare.

Taking out the DPF and doing the software cheat I guess is an option - but how does this affect your insurance in event of an accident? and I think its an MOT fail now too?

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12 hours ago, HawkeyeLawrence said:

...[we] just unbolt the downpipe from the turbo, give it 4 squirts of the cleaner, 4 squirts of flushing concentrate, bolt back together and drive in 3rd gear at 50mph for a few mins in rejuvenation mode. We charge customers £800 for this...

Crikey!  Nice work if you can get it...  :biggrin:

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So here's an interesting thing.  My friend (who is a significant petrolhead with a long Subaru history, and owns a Richard Burns Special Edition Impreza) has a very high opinion of the local dealers here in Carlisle, Stan Palmer Ltd.  So I went in to find out how much they would charge for a replacement Forester DPF, fitted.  They replied - -

"Dunno, mate, never had to do one.  We have cleaned the odd one, but only on cars which spend their lives pootling around town with a cold engine.  We charge £50 to clean the DPF."

They also said that to avoid crank problems I should look for a 59-plate or later (i.e. one that has a VIN where the 10th digit is "A", "B" etc., meaning late 2009, 2010 etc.) because the crank and bearings were redesigned at that time to cure the crank breakage problem.

An interesting alternative view...

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Later models with revised crank is best (done at least 2 crank revisions), they also have benefit of better component and software revisions.

Injector relearning is a mode the ecu goes into to check relative injector function and calibrate itself. Injectors are coded from factory and when replaced this code has be entered into ecu so it knows base values of new injector .

DPF is bit of hit and miss issue, driving type plays big roll but so does subaru software versions. Ideally dpf's should be strippable so easily manually cleaned at service times, regen and chemical cleaning is not great for environment or owners wallet . Back pressure from dpf reduces engine efficiency massively and costs owner a fortune over life of vehicle. Removing it not option as ilegal and mot failure ...

If buy diesel forester just try buy latest model can and test drive it at least twice for prolonged varried drives (make sure clutch feels nice) and try check previous service issues via dealers etc. Later models and latest software mixed with high mileage use tends give little issue but if a short tripper or not doing high enough anual mileage reap financial recovery then diesel is big expense .

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3 hours ago, Mr B said:

Later models with revised crank is best (done at least 2 crank revisions), they also have benefit of better component and software revisions.

Injector relearning is a mode the ecu goes into to check relative injector function and calibrate itself. Injectors are coded from factory and when replaced this code has be entered into ecu so it knows base values of new injector .

DPF is bit of hit and miss issue, driving type plays big roll but so does subaru software versions. Ideally dpf's should be strippable so easily manually cleaned at service times, regen and chemical cleaning is not great for environment or owners wallet . Back pressure from dpf reduces engine efficiency massively and costs owner a fortune over life of vehicle. Removing it not option as ilegal and mot failure ...

If buy diesel forester just try buy latest model can and test drive it at least twice for prolonged varried drives (make sure clutch feels nice) and try check previous service issues via dealers etc. Later models and latest software mixed with high mileage use tends give little issue but if a short tripper or not doing high enough anual mileage reap financial recovery then diesel is big expense .

Thanks Mr. B, that's really useful.  At the moment I have a budget that is limited to an earlier Forester.  I could just about afford a '95 model with at least one crank redesign.  Perhaps my Skoda will last another couple of years and then I would be able to afford a slightly later model - but then, I need to get up those pesky construction tracks in the meantime...  :mellow:

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31 minutes ago, Mr B said:

could look at raising the skoda 60mm with custom springs from springcoil or I think weitek done rubber spacers for vw/skoda !
Doubt get anymore than 60mm though.

Interesting thought!  I think rubber spacers are only for the rears, aren't they?  It's the clearance under the sump that causes problems.  Probably a bit late in the life of this particular Skoda to be thinking of new springs...

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