Nissan Qashqai - DPF Problems

[OLTB]

Evening all

My seven year old diesel Nissan Qashqai limped home last night at 20 mph (apologies to those behind me) and this morning I was told by the chap at Halfords Autocentre that it was probably the DPF (I have since looked up what this means). This evening it was confirmed that it was the DPF and they can't fix it (there were a few other errors that came up on their computer system when they ran a check). It's starting to sound expensive but I thought I'd ask here if this is something that needs replacing or could it be 'washed out' at a cheaper cost? Halfords said they would recommend a specialist close by but it looks like I'll be without the car for a while I think. I don't think the car is worth more than £3k or so (it's done 155k miles) so we shall see...

Any help/enlightenment would be appreciated - it's just a shame that at an expensive time of year, this crops up

Cheers, OLTB.

[staffordian]

I'm guessing that it's beyond the point at which you can try to regenerate it with a long steady run?

I know it went into limp mode, but have Halfords managed to overcome this by resetting the codes?

If it will run again I would be tempted to try a steady twenty or thirty mile run in third or fourth gear at 50mph in the hope you can burn off at least some of the accumulated crud. That's assuming you can find a road which will allow this!

Failing that, there are folk who claim they can clean them but I'm not sure how successful they are in reality.

These DPFs are the work of the devil, and seem to cause trouble even for those using a diesel in the way engines fitted with DPFs are supposed to use them...

[OLTB]

Thanks staffordian - I can't understand how it's happened as I drive to work daily (a 50 mile round trip - an hour each way) and most of that time is steady driving at 40-50 miles an hour. Perhaps it's just the miles I've done and a build up over time.

I'm picking it up this morning and I'll ask if they can reset the codes as you suggest so I can at least drive it to another garage for repair without annoying the drivers behind me.

Maybe I'll get a hybrid next time!

Cheers, OLTB.

[jackdaww]

Maybe I'll get a hybrid next time!

Cheers, OLTB.

==========================

or just a straight PETROL will avoid DPF issues.

[staffordian]

I'm picking it up this morning and I'll ask if they can reset the codes as you suggest so I can at least drive it to another garage for repair without annoying the drivers behind me.

Cheers, OLTB.

I'm not certain resetting the codes will temporarily overcome it, but worth asking.

[ten0rman]

Thanks staffordian - I can't understand how it's happened as I drive to work daily (a 50 mile round trip - an hour each way) and most of that time is steady driving at 40-50 miles an hour. Perhaps it's just the miles I've done and a build up over time.

And that, as far as I know, is the problem. You are just not working the engine hard enough.

When we bought our petrol Avensis (nearly 6 years ago) to replace the previous diesels, I looked at as many recommendations as I could find. It seemed that in order to avoid DPF problems we needed to drive at 60mph in top (or presumably the same rpm in lower gears at lower speeds) for 20 mins. minimum. Unfortunately we could not guarantee to be able to do that, so back to petrol. I pity really because I do like the slogging power of a diesel, but, c'est le vie, n'estce pas? Anyway, the Avensis does just as well apart from a reduction in mpg.

Regards,

ten0rman

[OLTB]

Ahh, I see - well, I’ve been told to take it back to the dealership as it’s too complicated for the other garage. I think I’ll fix the problem, and use it towards a newer car.

Cheers, OLTB.

[bungeejumper]

£1200 probably for a new DPF, sadly. It's a kind of tax on diesel cars when they get to a certain age - although, as some have pointed out, it's more of a problem for cars that don't get the occasional "Italian tune-up". And it's one of the reasons why I've switched back to a petrol car. (Which also returns better mpg after a long hot 'decoke' run, but that's another story.)

There's another way of looking at it. If your car has done 155K and now needs £1200 spending on it, that equates to a cost of about 0.8p per mile, which is probably less than what you're spending on tyres, and considerably less than the savings you're making from having a diesel engine in the first place. I'm guessing that overall you're still quids in.

I have no personal knowledge whatsoever about this, but I gather that sometimes the automatic regeneration that's supposed to clean up your DPF can fail to happen, for one reason or another. And that a combination of manual resetting and/or cleaning can do the trick, or at least buy you time.

https://www.whocanfixmycar.com/services ... lter-clean has a video which might be informative. £175 might be worth a punt?

BJ

[jackdaww]

the root issue here is small vehicles trying to be a refinery for a crude fuel - kerosene.

it difficult and wide open to abuse by both manufacturers and users.

[wydffa]

I only use my volvo V70 for long trips but the DPF failed (no warning light, valves damaged) after 180K miles. My local garage replaced it with a used DPF from a low mileage write-off.
I will not buy another diesel.

[OLTB]

Thanks all - I contacted the dealership and they said to get my recovery service (The AA) to see if they can perform a 'static regeneration' and if not, to recover it to them.

The AA chap met me at the Halfords Autocentre and plugged in his computer which showed a reading of 41mg (I think) of soot which was too much and computer said no...

He then made a few calls to some local chaps he knew and one of them said that they clean DPFs and they'll have it done by either next Thursday or Friday. If it works, I might be lighter some hundreds of pounds, but at least it's not in the thousands.

As many of you have said above, this is the last diesel I get - I drive a few miles each year (25k or so) so fuel bill will be higher, but I think it's worth it.

Cheers, OLTB.

[jackdaww]

Thanks all - I contacted the dealership and they said to get my recovery service (The AA) to see if they can perform a 'static regeneration' and if not, to recover it to them.

The AA chap met me at the Halfords Autocentre and plugged in his computer which showed a reading of 41mg (I think) of soot which was too much and computer said no...

He then made a few calls to some local chaps he knew and one of them said that they clean DPFs and they'll have it done by either next Thursday or Friday. If it works, I might be lighter some hundreds of pounds, but at least it's not in the thousands.

As many of you have said above, this is the last diesel I get - I drive a few miles each year (25k or so) so fuel bill will be higher, but I think it's worth it.

Cheers, OLTB.

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good decision!!

[monabri]

My wifes Mondeo went into limp home mode approx 3 yrs ago. My mate ( a mechanic) 'cured' the problem. He simply started the engine and revved the nuts off the car. It's been fine since.

My wife drives a 2 litre diesel about 2000 to 3000 miles per year. When we took it for an MOT a month ago, I was in the garage when they did the emissions...I doubt a maniac joy rider with a death wish would have revved the engine so much.

So, try warming the engine and then treating it mean...real mean!

[sg31]

DPF's regularly cause problems. Most times they can be put right by the following in order...

Run the engine hard for a period say on a motorway in a lower gear than normal

There is a fluid that can be poured in the fuel tank, wait until the emergency fuels light comes on, pour the fluid in and run for a few miles at high revs

A suitably equipped garage can get the car to run through a regeneration process where the car engine is taken through certain rev ranges in a set sequence which should regenerate the DPF.

There are companies that can clean the DPF using chemicals (I think)

Replacement of DPF is the last resort. In my case a replacement would have cost £700, buying from the manufacturer was £2000.

I know all this because my engine management computer showed a DPF fault and I had an after market warranty. The warranty people ran me through the whole process.

(There may be other processes available but these are the ones I am aware of)

[OLTB]

Well, the garage have called and said that there is a split boost pipe and some glow plug faults. The soot reading of 41g apparently isn’t excessive. Total cost to repair everything and re-gen DPF is £430 plus VAT. I don’t know what a boost pipe or glow plugs do but apparently they all could affect DPF so just pleased it’s fixable.

Thanks for all your responses chaps and hopefully will have wheels soon.

Cheers, OLTB.

[bungeejumper]

Well, the garage have called and said that there is a split boost pipe and some glow plug faults. The soot reading of 41g apparently isn’t excessive. Total cost to repair everything and re-gen DPF is £430 plus VAT. I don’t know what a boost pipe or glow plugs do but apparently they all could affect DPF so just pleased it’s fixable.

Congrats! Affordable surprises are my favourite kind.

I don't know what a boost pipe is either, except that your turbo won't achieve very much without one. I do know that an air-leaky piece of duct to my intercooler was enough to kill all the acceleration on my diesel Focus and reduce it to limp mode. Your glow plug faults might be coincidental - TBH they don't do much except on very cold mornings, so an existing long-term problem with them might not have been noticed for a very long time. Either way, they're not an very expensive item.

BJ

[Mike88]

Glow plugs are the devil to remove. Often they break and then the expense occurs by stripping down the head and boring them out. Make sure you get a fixed price from the garage before they start work.

[bungeejumper]

Glow plugs are the devil to remove. Often they break and then the expense occurs by stripping down the head and boring them out.

Indeed. There are a hundred reasons for not stripping down the cylinder head unless you really have to. But I/my garage had no problems with replacing mine at 110K, so here's hoping for the O/P.

I thought there were tools for removing broken plugs in situ? And then you'd just follow through with a helicoil to rebuild the thread?

BJ

[Mike88]

Glow plugs are the devil to remove. Often they break and then the expense occurs by stripping down the head and boring them out.

I thought there were tools for removing broken plugs in situ? And then you'd just follow through with a helicoil to rebuild the thread?

BJ

You could be right but surely there is a danger of metal fragments falling into the engine which could be catastrophic. Whatever the solution let's hope the repair goes well for the OP. It would be good to receive some feedback as many diesel owners could benefit from the OP's experience.

[OLTB]

Well, car now fixed and running well. The list of faults are as follows:

1. Boost pipe to manifold was split
2. Glow plug failed which short circuited the glow plug module.

These all helped in upsetting the DPF sensor.

The work required was to replace the boost pipe, glow plug and glow plug control module and then perform a DPF regeneration.

Total cost was £430 + VAT.

Oh hum

Cheers, OLTB.