Diesels - Keeping DPF/EGR Clear

[Mr Bump]

I am 'possibly' looking at moving from an A5 to a Q5 and pondering which to get.  I only do around 8k miles/year, mainly short journeys with my commute being town/A roads in stop/start traffic, so I have read it may be unwise a bad idea to consider a diesel.  However, the mpg from a petrol/plug in Q5 (once battery depleted) is pretty lousy so I am still tempted by the diesel, plus I do like the torque they provide.

Once or twice a week I can easily arrange to take a slightly longer route home from work which would include a 14 mile drive on dual carriageways where the car would warm up properly (that drive takes around 25 minutes).  I can also take it for a blast at the weekend if needed.

Would that mix of driving be likely to see me have issues with diesel or should that suffice to keep it clear? I realise that's in an ideal world.

Thanks.

[Steve Q]

Yes you could end up with blocked dpf with soot if the engine isn't run hot for long enough. I'd definitely advise a petrol in your case. 

Also I'm not sure what towns/cities you visit but diesel will be more of a problem if emissions zones are brought in. 

[Mr Bump]

Thanks Steve.  I have read differing opinions today on what 'short journeys' constitute, along with claims from TDi owners that they have never had an issue.  Similarly there are people who have.

As above, I'd be making sure the car had a 20 - 25 minute motorway run once a week whereby it would be warmed up properly - is that likely to be sufficient to offset the daily short journeys Monday to Friday, and avoid the dreaded DPF blocking?

Thanks for the help.

Edited November 19, 2024 by Mr Bump

[Steve Q]

Not necessarily as it depends on when the car wants to do a regeneration on the dpf. 

Unfortunately dog and egr issues are common problems on most modern diesels these days. Use the search function to see the different threads to see what I mean 

[cliffcoggin]

Paul.

It makes no sense to do unneccesary journeys merely to keep the DPF clean, which is unlikely to work, and in the same breath be concerned at the mpg of a petrol or hybrid. If you do mainly short journeys a hybrid would be ideal for you as long as you can recharge the battery at home.

[Mr Bump]

Thanks Cliff, though I partly disagree.  Having spoken to a number of dealers there's a consensus that a petrol Q5 is 'very thirsty', so I'm not sure a 20 minute blast in a diesel would be enough to offset the cost between the 2.  Whether or not it would solve the DPF issue, I'll defer to you as I am not that well informed on the matter.

Ref the hybrid whilst it's a good suggestion, I am not sure it's any different to a petrol to be honest, and perhaps even worse.  The official range for a Q5 PHEV is around 26 miles so in the real world that's likely to be around 20 at best.  That's not enough to even cover my daily commute to work on a full charge which means that for some proportion of the journey I'd be driving a petrol with the added burden of a massively heavy battery.  I am not sure that's a great solution.

I do have the concerns about the diesel/DPF issue which is a real shame as the Q5 would be my preference, all told.

[cliffcoggin]

Paul.

If you are limiting youself to only a Q5 then you will have to compromise between range, fuel cost, and DPF problems.

Perhaps it's time to consider another model or even another brand that would give you more options.

[Steviebobs]

Hi, I'm new to this site. I have had problems with my DPF for 4 months, no DPF warning light just engine warning light and flashing coil which put me into limp mode.

I was told on 3 occasions that the filter was blocked and couldn't carry out a regen. I took it to Lookers in Guildford (Audi) they had it for a day (£800), they said that they tried 2 times to regen,they couldn't do it so said the only option was a new DPF (£3500). The cars only worth £5000. I booked it in for a DPF clean but while I waiting for the date to arrive I tried a regen with my £220 diagnostic tool (Launch).........It worked, cleared engine light and coil back to full power. It's been a week now.

It's only done 85000 miles but I only drive short trips but now I'm doing a longer trip a once a week and using DPF cleaner/Regenerator.

I will say that the car worked well just in limp mode. I hope this may help others having the same problem.

[Stevey Y]

7 hours ago, Steviebobs said:

Hi, I'm new to this site. I have had problems with my DPF for 4 months, no DPF warning light just engine warning light and flashing coil which put me into limp mode.

I was told on 3 occasions that the filter was blocked and couldn't carry out a regen. I took it to Lookers in Guildford (Audi) they had it for a day (£800), they said that they tried 2 times to regen,they couldn't do it so said the only option was a new DPF (£3500). The cars only worth £5000. I booked it in for a DPF clean but while I waiting for the date to arrive I tried a regen with my £220 diagnostic tool (Launch).........It worked, cleared engine light and coil back to full power. It's been a week now.

It's only done 85000 miles but I only drive short trips but now I'm doing a longer trip a once a week and using DPF cleaner/Regenerator.

I will say that the car worked well just in limp mode. I hope this may help others having the same problem.

Hi have you now realised that is all Audi want to do is sell you a new DPF, good skills with the additive it definitely keeps it at bay, considering that nearly all branded DPFs have Silicon Carbide cores they should outlast the car thats why any DPFs they remove are sold via a third party, sonically cleaned and sold as refurbished, makes you smile when you think £220 versus £10,000 for IDOS managed to do the job don't you detect the faint odour of lying Bar steward.

Steve.

[Steviebobs]

That's what I thought, they had no interest in cleaning the DPF, 10 days after that appointment I needed to lift the bonnet to add wind screen wash, Audi had not put the plastic engine cover back. When I went back to complain and get my cover the guy said, I thought that I would get a new DPF. I think that it was a very sloppy service.

 

[Stevey Y]

3 hours ago, Steviebobs said:

That's what I thought, they had no interest in cleaning the DPF, 10 days after that appointment I needed to lift the bonnet to add wind screen wash, Audi had not put the plastic engine cover back. When I went back to complain and get my cover the guy said, I thought that I would get a new DPF. I think that it was a very sloppy service.

 

Hi Stephen, that would of equated to you need a new engine cover on your next visit, only £160, there are no  lengths to which these people wont go to extract more money from your wallet, who do you think pays for the spotless work shop and beyond Cr@p technician practises, many years ago my friend worked at a Ford main dealers and because he was new was put on fleet services, when he went to draw oil and air filters for the latest batch he was working on he was told NO, they only change them every third service and to just give the canister filters a wipe with brake cleaner to make them look new, this had the effect of causing multiple cam failures which the dealership replaced under warranty as Ford HQ was supplying the parts and paying the labour, Win/Win for the dealer.

Steve.

[Steviebobs]

I agree, it's got to the point now that find it very difficult to trust any tradesman/company. Mechanics is one of those trades where you do need trust, do they drop the oil or suck it out, do they really change filters etc and of course the hours they charge for labour, did it really take 3 hours or are they adding an hour on because they say it was more difficult than they thought.

[Steviebobs]

Just asking for info. I'm looking for a hardback Haynes manual for an 2011 Audi q5 3 litre v6 diesel. I've tried online and can only find downloads, i like to have the book not carry my computer around with me. If anyone knows where to get one. Much appreciated in advance. Steve