Advice on diesel (DPFs), buy or avoid?

[oxblood8]

Hi All

So I'm still in the process of potentially replacing the RS4 and have shortlisted a previous model SQ5 and an A6 Allroad (2012 onward). However my overriding fear is having DPF issues as I see this come up often (most notably Morrie and his SQ5).

So I'd use this as a daily. I work literally 5 minutes from work so that obviously is a very short trip which wouldnt allow the exhaust to get up to temp to trigger the regeneration. I also once a week play sport which is a 20 minute drive each way. I assume this length of trip would be the ideal time to get the exhaust up to temp and let the DPF regeneration do its thing?

I'm just wanting opinions on whether given my type of driving, should I take the plunge or avoid diesel altogether.

[Topgun]

Yes the powerful bi-turbo diesel of the SQ5 is a great drive - however, doing very short trips .... I would definitely say is not optimum for diesels. I live in Canberra and I feel the beast always needs a good run to burn off diesel soot, buying good diesel (not truck diesel helps) ... I've even switch off the stop/start to keep things running smoothly. Potential future problems with the DPF is my main worry too, as I also followed the saga that Morrie had a while back. The DPF regeneration is important to flush things ..... mine works fine ..... but I think Morries DPF no longer worked .... which started the drama with Audi to get it fixed under warranty ... a sad result. Based on what you tell me with your driving distances .... maybe err on the side caution here ..... and not go for a diesel ?

[kctt]

I think the key is to learn why you get this issue to begin with. After learning about Morrie's troubles with his DPF, I modified my driving habits.

Firstly, I now drive on manual mode to allow the revs to be around 1900/2000rpm when driving around the suburbs. In auto, at around 60km/h, the revs tend to be a lazy 1200-1300rpm, no where near the required revs for the DPF to operate. Even on the freeway cruising at 100km/h on auto, it is not be enough to get the revs to 1900rpm.

Secondly, I pour a can of Liqui Moly every couple of thousand kays for maintenance. This also allows your DPF to start burning off soot at lower temps and thus you don't have to religiously ensure your revs stay at 1900/2000rpm.

Before I did this, I will always hear the DPF operating after short trips (less than 10 mins). After around 5000kms of driving like this, I've not heard the DPF come on since. Touch wood, this will prolong the DPF life.

Driving short distances are generally not good for cars regardless. In the case of the RS4, short distances will result in faster carbon buildup. Different problem, same cause.

Good luck with your decision. The SQ5 is a cracking car, so much so, I've not missed moving on from my RS4 (except maybe for not having a manual gearbox).

[itaplikeabiatch]

this has been one of the biggest issues with me considering going to the sq7. this whole dieselgate thing and a lot of diesel conspiracy issues has scared me off getting a performance diesel. does anyone know if the sq7 will suffer from the same issues? the whole dpf thing is a big putoff for me.

[Morrie]

The good old DPF issue hey. As for the SQ7,yes it will be susceptible to DPF issues just like any other deisel that has a DPF. As I wrote in one of my posts(I can’t remember which one it was...Motor or Wheels magazine)on average over 50% of DPFs in Australia are failing or experiencing problems just after the 60,000klm mark(they should last over the 200,000klm Mark). As for buying a deisel SQ5 and only driving it 5mins to and from work every day and 20mins back and fourth to sport once every weekend,I don’t even think the Liqui Moly DPF solution will help you. Remember,I live in Central QLD,no traffic lights and one roundabout in Middlemount where I live. I do not do too many short trips at all. The closest big town is 1.5hrs away and I always make sure to give my SQ5 a good workout on most trips. Yet the clowns at Audi Australia still questioned my driving style even though Audi Townsville backed me and said I drive my car in a fashion as not to cause the DPF problem that I had. Still Audi Australian declined to fix/replace my DPF. So once the Townsville Audi guys done their tricky stuff and fixed the DPF I started using the Liqui Moly DPF solution every 3 or 4 tanks of deisel. So if your feeling lucky buy the Deisel SQ5(it is a wonderful machine,I still love mine but when I finally decide to get rid of it I will never get a deisel again)but if you do not want to risk it buy a unleaded veh.....mabey get a top of the line GT KIA Stinger!.

[oxblood8]

Thanks for the replies everyone. I think the smart decision for me would be to stick with a petrol, I think it would be just too much of a headache constantly thinking/overthinking when driving the car to really enjoy it. A shame really as I do love the SQ5 and the A6 Allroad.

Just talking to a mate here at work this morning, he was telling me in the latest Wheels mag someone wrote in saying they purchased a secondhand Q5/SQ5 with 52,000 kms on the clock. Almost immediately the DPF failed and had to be replaced. When replacing it, they found that it had already been replaced as the DPF that was on it didn't match the one when manufactured. So 2 DPFs in ~55,000 kms!

A mate of his has a Porsche Macan with 8,000kms, DPF needs replacing, he's spewing that he didn't get the petrol as he loves the car.

[momento1]

Gents i have to pip in here and say i couldnt disagree with you more (in part or in full)


Ive had my 2013 SQ5 for 98,XXXkm now and my wife mainly drives it to work 3 days a week (approx 50-80km round trip in moderate traffic), and just to do the school runs on other days which is a lot less.
when i get in the car, which is usually once or twice a week, on weekends, i do give it a spirited drive, but not anything illegal.
I either drive in sport or manual mode and down shift to slow down, and get the revs up. But again nothing extreme cause i have the kids with us (although they always giggle on the torque accel capabilities)

Car is strong as day one, and no hints of anything untoward.

I was literally in the car last night telling my missus how much i love this car. And she completely agreed!

So i cannot rate it highly enough.


I even went to the dealership to look at trading to the newer SQ5, and even the sales guy looked at me and said "Honestly if you have no problems or concerns with your SQ5, why are you trading? Its the best model Audi have brought out in a long time!" He even went as far as saying for driving experience it is still better than the new model

Thats just my experience anyways

[Morrie]

Fair enough mate,I’m glad u haven’t had any dramas withe the DPF on your SQ5. Mine is also a 2013 SQ5 I bought brand new and it has 935000klms on the clock now. The SQ5 might work for you and at least your wife is doing 50-80kay trips 3 times a week. That’s a lot different then doing 5mins to and from work 5 times a week as oxblood8 is talking about(don’t forget a Audi DPF costs $6000),that’s asking for trouble. Plus I think it’s absolute crap having to have to drive a veh harder every now and then just because of the DPF(not that I don’t mind driving it harder).

[momento1]

Fair enough mate,I’m glad u haven’t had any dramas withe the DPF on your SQ5. Mine is also a 2013 SQ5 I bought brand new and it has 935000klms on the clock now. The SQ5 might work for you and at least your wife is doing 50-80kay trips 3 times a week. That’s a lot different then doing 5mins to and from work 5 times a week as oxblood8 is talking about(don’t forget a Audi DPF costs $6000),that’s asking for trouble. Plus I think it’s absolute crap having to have to drive a veh harder every now and then just because of the DPF(not that I don’t mind driving it harder).

True. And i understand that. I just never considered it a problem and havent heard enough horror stories to sway me otherwise.

I guess my other theory is that if the dpf does die on me, all im going to do is remove it and get it tuned out with an aftermarket tune.
Better to pay 1500 odd instead of 6k

[Cristian G]

I’ll chime in here too.
While I didn’t have a SQ5, I did have a Q7 3.0tDi. I never had a problem with the DPF in the time we owned it and my wife did a lot of round town driving in Sydney. There was a couple of times I noticed the car going through it’s own regen cycle, but it was not a common event.
I’d also like to point out that this is not an Audi only problem. The current 200 series landcruisers are also suffering from DPF issues, and I’ve heard whispers of the latest Prado also, but I don’t know if the Prado actually has one. My 2014 150 series doesn’t.
I think it’s the typical beat up. You hear a lot of stories of problems, but you never hear (except for momento above ) how many people don’t have problems. I’m not denying it’s an issue, I’m just saying you hardly ever hear when everything’s great.