Hi Guys

What's the chances of DPF failure when buying a high mileage diesel .......80k plus. Is there any way of checking how close to failure a DPF is.

 

Regards

Benterrier

It all depends on the type of driving the car has done, big mileage isn't always an issue for DPF's, there are cars on Briskoda that have hit 200,000 miles without issue.

 

You can plug into the car using VCDS and check the ash content inside the DPF. As the DPF regenerates it burns off the soot and leaves behind a small amount of ash, once the ash reaches a certain level the DPF begins to struggle and is a key indicator of the DPF's likely demise.

Edited 23 May, 201610 yr by silver1011

A lot will depend on quality of fuels as well, and if the previous owner skimped on oil changes etc.

If they used cheapest fuels without additives, and went to max before oil changing then there is a chance other parts are going to cause problems such as turbo oil feed pipe being partly blocked

From Honest John: "the problem is that diesel particulate filters have a limited life of perhaps 80,000 to 100,000 miles before they become completely clogged with ash, cannot be cleaned out or 'replenished' and need to be replaced."

We've got toledo 1.6 tdi taxis with 200k+ that haven't had any issues with the dpf, we have one with 187k that's still on its original turbo and clutch and flywheel. Only issues we seem to have is the egr valves going between 60 and 100k. Cars are serviced every 10k

Thanks guys.I guess by your replies several things influence the service life of the unit. How is this regeneration activated, bye the car or driver? and what does it involve.

There is no sure fire way to know the real state of the DPF. its the same as the engine, clutch, cataylst & other mechanical parts on the car. 

 

If it was driven normally, serviced regularly & kept in a good state of repair chances are you shouldn't have any problems.

Modern cars & engines should run to 200k km and above with only minor maintainence if looked after correctly.

 

With all used cars, each car has to be treated individually as many factors can affect the engine life.

If its 1 year old with 80k of 4 years old with 80k there a difference.

Check the service logs, have any special repairs been done, has it been driven evenly over its life, did the last owner keep in 2 years or sell after 2 months etc etc etc)

 

 

In general I would say a diesel with DPF from the last 3-5 years should be no problem at high mileage as the technology is somewhat proven.

There are not many O3 owners I can recall having problems with the DPF at higher mileage so far but it is a realitvely young car.

Diesels from 5-10 years ago I would be more wary of as the technology was new then & there were many problems (hence many peoples fears now about DPFs)

Thanks guys.I guess by your replies several things influence the service life of the unit. How is this regeneration activated, bye the car or driver? and what does it involve.

 

DPF/Regeneration functionality is automatic on all cars (even older ones).

The engine control unit does all of the calculation & control.

The driver has nothing to do except drive the car normally.

It won't regen if the tank is less than a quarter full. That's what I got told but dunno if that's true or not

From what I understand VW group cars are now much better with DPF filters and regens in general. Think this has something to do with the filter location and the bits they needed for the Euro6 rules.

 

Here's some more information on DPFs I found 

 

http://www.hypermiler.co.uk/technical/the-diesel-particulate-filter-dpf-faq

 

I really wouldn't worry as long as its been serviced corrected using low ASH oil as recommended by Skoda.

Its a sod how the once relative simple diesel engine has become so complex and expensive to maintain. Gone are the days of my first diesel car, a mk1 5 speed diesel golf.

So progress and lots of money making ideas in the name of a healthier environment has led to this piece of unfinished technology, costing the unwitting motorist hundreds of pounds. I went for a test drive the other day and asked the salesman about DPF's ... He said we don't want to talk about those things now do we , jokingly! and its not covered in the warranty with this secondhand car your driving, its a consumable.

So my idea of a 2013, 90k mileage Passat tdi cr 140 for £7.500 ...(sorry but is a VAG car)isn't a great idea me thinks.

Thanks for your replies guys and sorry if I went off topic ....(Octavia 3)

Regards

Benterrier

Good excuse to remove it and remap it lol

I wouldn't instantly dismiss the purchase of a 2013 90,000 mile Passat on DPF worries alone.

 

As has been mentioned using good quality fuel, regular oil changes together with the right type of driving and DPF's can last well in excess of 200,000 miles.

 

Opinions on this vary wildly but in the event of a failure you do have several options:

 

1) Buy a new genuine DPF @ approx. £1,200 (fitted).

2) Buy a non-genuine DPF @ approx £600 (fitted).

3) Have the DPF professionally cleaned @ approx £300 (relatively short term fix).

4) Remove the DPF and code out the sensors @ approx £450 (concerns over legality, MOT tests and guilt!).

 

Either way the DPF is just one of very many potential money pits on any used car purchase. Modern cars are increasingly complex.

The turbo going will be just as expensive as replacing or removing the dpf.

I wouldn't instantly dismiss the purchase of a 2013 90,000 mile Passat on DPF worries alone.

As has been mentioned using good quality fuel, regular oil changes together with the right type of driving and DPF's can last well in excess of 200,000 miles.

Opinions on this vary wildly but in the event of a failure you do have several options:

1) Buy a new genuine DPF @ approx. £1,200 (fitted).

2) Buy a non-genuine DPF @ approx £600 (fitted).

3) Have the DPF professionally cleaned @ approx £300 (relatively short term fix).

4) Remove the DPF and code out the sensors @ approx £450 (concerns over legality, MOT tests and guilt!).

Either way the DPF is just one of very many potential money pits on any used car purchase. Modern cars are increasingly complex.

That is interesting as the Australian prices I have seen bandied around for a replacement new dpf are around 3 times more expensive.

VW parts here are very expensive which is why so many owners buy from overseas and pay shipping costs

I bought mine O3 with 106K km on clock no problems with DPF now I have 117K km mostly short trips in town. Had one warning DPF message but I was on highway so I helped it out do the regeneration. After there was no message so just to be sure I went to service and asked to check it up. They didn't say what percentage was DPF filled but they sad it would be wise to do DPF forced regeneration I agreed so they did that and now all is ok! Ones a month the car does it regular DPF regenerations in traffic or on parking lot. Car was old little more than a year and a half when I bought it so I assumed first owner did lots of highway trips, and he was french sales pharmacist. Car was on variable service I switched it to fixed and when I got the car I changed the engine oil just to be safe. Hop this helps.

 

DPF is a problem with leasing cars when they are on variable service plan which is bad cuz oil is not replaced on time and it gets dirty. Then bad fuel is next problem, always put in premium, class diesel. And for end. Short tips are problem if first two things are ignored.

 

So fixed service plan with sooner oil changes and quality fuel should not kill your DPF if you are driving short trips in town, but it's not a bad idea to go to few longer trips!

Edited 26 May, 201610 yr by Croat

Just buy an economical petrol.....only turbo problems to worry about then.

The 1.2 and 1.4 TSi can do up to 50mpg if driven sensibly. My 1.2 averages 45mpg.

DPF/Regeneration functionality is automatic on all cars (even older ones).

The engine control unit does all of the calculation & control.

The driver has nothing to do except drive the car normally.

When I had my first VRS there was a note in the service manual about how to get the DPF to regenerate. I had to do it 3 or 4 times but after 120K miles I never had to replace it

 

IIRC it was something like 50mph in 3rd gear for 15 minutes

 

Handy little guide here also http://www.vwgenuineparts.co.uk/DPF_regeneration.shtml