12 replies to this topic

[igrf]

I'm not sure if this is a question which I can ask here as I'm usually baffled by the technical expertise of the topics that 'live' in this technical section of the board ...

I only have some basic knowledge about how cars and engines work so am looking for some help

Day to day I drive a subaru outback diesel, it's a wonderfull car, I really like it.
Obviously it's no race monster but for day to day use I find it to be best compromise for my needs.

It has a 2l 4 cyl boxer diesel engine with an open diesel particle filter and commonrail injection.
I have a fuel card (paid by my employer) which is limited to the 'TOTAL' brand, which economically enforces me to always fill her up with total excellium diesel fuel.

In the 90000km that I driven the car so far, the dealer has replaced 6 injectors because they were malfunctioning.
According to him this is because of the fuel that I use.

I know that Toyota made the news (at least here in the benelux) a couple of years ago with a similar problem. I know that the injection system that subaru uses is based on the same common rail system in these toyota engines.

Now the question :
- Can this really be fuel brand related ?
- and if yes can someone explain what the difference is between this and other brands.
- and does anybody know what is in this fuel that doesn't get along with my engine ?

[jcbc3]

I would more assume an electronic problem in your CPU. The fuel may be a convinient excuse of not aditting 'guilt'.

[peroa]

If you have bad quality diesel try using additives.
Do total have a higher biodiesel percentage than others?

[Lee Nicolle]

While I know very little about diesel fuels I do know that some brands can be better than others. And different countries fuels are way different. Modern diesel engines are far more particular of their diet unlike some older ones that would burn almost anything liquid and combustible.
Landcruiser diesels seem to need the injectors cleaned very regularly or they go very gutless and thirsty, so do others I believe.

[igrf]

I would more assume an electronic problem in your CPU. The fuel may be a convinient excuse of not aditting 'guilt'.

The car is still covered under warranty and the dealer has already replaced/checked a number of item on the engine.
Airflow meter, fuel injection pressure regulator, cleaned the EGR several times, replaced the injectors etc so I'm not sure if it has to do with admitting guilt.
I also have a written (email) confirmation that they will keep replacing the injectors free of charge after the warranty expires.

If you have bad quality diesel try using additives.
Do total have a higher biodiesel percentage than others?

Officially all diesel fuel should adhere to the EN590 specification and can should contain around 5% bio diesel.
I say offically because rumour goes that total (which is a french company and in france they have a bigger % biodiesel) will sometimes bring 'french' fuele on the belgian market.

[jcbc3]

But if it wasn't your car, but a generel fuel problem, I would assume that all French Total customers would be grinding to a slow stand still? Or any other drivers in Belgium that uses Total?

Sorry, if I sound like a negative Nellie. It just seems very far fetched to me, that there should be a generic fault with Totals diesel fuel.


(but I can add another horror story of my own. I drive a V6 Audi (2003 vintage) where the engine light has come on. The error reading is something like 'mixture too lean on left and right cylinder bank'. I have had 'everything' changed and tested. It has also been tested for air leaks in the plumbing leading in and out. But the engine light comes back on with the same error message after a couple of days every time it's reset. All this means that I can't sell the car or get it to pass the bi-yearly inspection)

Edited by jcbc3, 05 February 2011 - 14:23.

[Magoo]

Now the question :
- Can this really be fuel brand related ?
- and if yes can someone explain what the difference is between this and other brands.
- and does anybody know what is in this fuel that doesn't get along with my engine ?

Short answer: go over the dealer's head a bit and contact your factory service rep, who if necessary (and ideally) can hook you up with a field service engineer. Your questions for them: Is there something wrong with your brand of fuel, and if so, what is it exactly? The dealer can arm-wave, point fingers, or pass the buck, but these guys really can't. They have to give you a hard, straight answer that solves your problem. If they don't have an answer straight off the tops of their heads, that means the manufacturer hasn't identified a specific problem with the fuel and the problem is likely with the vehicle. If they have identified a specific issue with the fuel, then you have something to talk to the fuel company's technical people about.

Meanwhile, I am curious as to the symptom(s) with the vehicle that leads to the injector replacements. Also, do the injectors fail randomly or is the problem isolated to one or two cylinders? When components are repeatedly replaced, there are generally three reasons: 1) faulty component 2) faulty installation 3) faulty diagnosis, and not necessarily in that order. There are a million ways this can happen, but here is the classic on electrical failures: part appears to be faulty, so the mechanic replaces it. But it's not really the part, it's an electrical terminal or connector at or nearby the part. Replacing the part jostles the connector enough to allow it to work for a while. Then it stops working again, and the component is replaced again and it works for a while again, and so on, until you are out of warranty, ha.

[PJGD]

You need to tell us more about how the problem manifests itself.

What are the symptoms that make you take the car back to the dealership?

Hard to cold start? Rough running? Cylinders that have dropped out [mis-firing]? Loss of power? Change in engine sound? Stalling at traffic lights?

What, if any, are the diagnostic codes that are reported following the problem?

Does the problem occur suddenly and with little warning (example: an electrical issue), or does it develop over time (example: clogged DPF).

How often has the fuel filter been changed? Next time look at the filter (cut open if necessary) to look for gunk and sludge. Is there a WIF (water-in-fuel) sensor and how does water get drained out of the system?

That car has a Denso common rail injection system. I would try to speak with their service division and see what they have to say. We will be interested to hear.

PJGD

[igrf]

The story has been going on for a while so I'll try to recap the events that happened.

It all started when I had the car for a year and it had about 30000km on the odo.
On random occasions the engine stalled, but only when I pressed the clutch.
So for example while arriving at a roundabout, step on the clutch to downshift to second and the engine stalled which resulted in a couple of dangerous situations where I got 'stuck' in front of other traffic.

First thing they did was replace the fuel filter which didn't make a difference.

Next time the dealer cleaned the EGR and replaced a high pressure sensor on the common rail injection pump.

The car ran better but the problem came back after a while.
Additionally I was also unable to start the car again without pressing HARD on the accelerator.
Cold starts were not a problem but if the engine was warm and I turned it off, it would start again but wouldn't run on idle, it would just stall.
Only when revving it to 3000-3500 it would return to a stable idle 900(ish) rpm.

They cleaned the EGR and replaced the same sensor again, additionally they also changed 2 of the 4 injectors.

This cured it for a while but the problem returned again.
In the mean time the problem was escalated to Subaru Belgium (by the dealer) and they installed some data logging equipment in my car which I ran around with for 2 weeks.
Not sure what they did with these logs but afterwards they came with a custom programming for my ECU.

Since this special program is in place, the car doesn't stall anymore. But this is an artificial fix because it somehow increases the revs in critical situations.
I sometimes see the revs drop (like the car is about to stall) but this is then corrected by increasing the revs again.
I also sometimes notice that the revs rise slightly when I press the clutch (without touching the throttle pedal).

So driving like that for a while the engine started to run more roughly, no change in cold starting or anything but it did feel like the power fluctuated while driving.
I mean that while keeping a constant pressure on the throttle pedal the car didn't keep a smooth pace, it felt like it moved slightly back and forth.

Back to the dealer which concluded that the injectors were 'broken' and all of them were replaced.
What I understood from the mechanic was that the 'corrective values' were too high which then meant that the injectors weren't able to deliver the correct fuel quantity.
They also cleaned the egr and all the fuel lines again. They also added some additive to the diesel in the tank.

The engine ran perfect until I had to fill her up again, after which she started to slowly develop the same 'unsmooth' engine running again.
Worst thing is that this isn't constant, so usually when I have time to go to the dealer then the engine will run ok.
But when I'm far away it will happen (Murphy ?).
Anyway I'm sure that it will get worse and in the end they will have to replace the fuel injectors again in a 20k or so.

PS : I’m not a mechanic so I have to rely on what they tell me, I only have some basic engine knowledge but am mostly unaware of the more advanced electronic control stuff.

[Lee Nicolle]

Methinks it has some electronic issues that they are unable to fix.
Though try a tank of a different brand of fuel. Though if like here in Oz most comes from exactly the same supplier anyway!

[Bargebear]

[quote name='igrf' date='Feb 5 2011, 02:59' post='4820573']

Do other Subaru Outback diesels have this problem?

[OfficeLinebacker]

Quite odd. Since you're tied to Total, I want to make sure--you fill it up from different stations right? Like not just the one by your route or whatever.

[igrf]

Do other Subaru Outback diesels have this problem?

Officially not ...
But my dealer told me that after the holiday period they had a number of cars which had problems with the injection system, all of them went to (or drove through) france.
The belgian subaru forum also has some other people complaining about total diesel and rough running and/or injector replacements.
Of course it's not such a popular brand so not too many people are driving them ....

Quite odd. Since you're tied to Total, I want to make sure--you fill it up from different stations right? Like not just the one by your route or whatever.

Yes I get my fuel from different locations, I even hardly ever get fuel from the same pump twice in a row so it's not limited to 1 petrol station.