SEAT Alhambra DPF repeatedly blocking

SEAT Alhambra DPF repeatedly blocking

Author
Discussion

HSmith22

Original Poster:

3 posts

18 months

Tuesday 23rd May 2023
quotequote all
After many years of my wife refusing to believe that driving the kids 100m to school in a 2L diesel could have any ill effects, last year's trip to cornwall was nearly scuppered by a blocked DPF.
Following an active region at the roadside, and another a few days later in St Ives when the warning light appeared again, I got a professional chemical clean when we got home.
From that day onwards (though I can't recall if this happened prior to the cornwall trip), the engine fan has kicked in after every journey of more than a few miles. It stays on for about 10 minutes, as if a region cycle has been interrupted. I've dropped it in to the local garage a few times, no fault codes exist so they've been scratching their heads. I've pretty much only used the car for 40 minute journeys to work, all motorway, since last year so the dpf should be pretty clear, or so I thought.
Last week, during a trip to the south coast, after 90 miles, DPF light came on again. Cue region at the garage, cleared from 35 grams of soot down to 2 grams. Three days later, another long journey of over an hour and a half, and the blocked light comes on again.
Garage now recommending a change of DPF.
Question to all you lovely wise folk, do you reckon the problem lies deeper? Would the ECU be having issues, hence no region cycles really happening? Do I run the risk of a EGR also being blocked? Am I throwing money down a deep deep well in trying to get this sorted, or should I finally say goodbye to the old girl (2014 , 68,000 miles?)
If anyone's had a similar experience I'd be really grateful to hear of how you fixed it.
Thanks.





Tomanybikes

987 posts

33 months

Tuesday 23rd May 2023
quotequote all
HSmith22 said:
After many years of my wife refusing to believe that driving the kids 100m to school in a 2L diesel could have any ill effects, last year's trip to cornwall was nearly scuppered by a blocked DPF.
Following an active region at the roadside, and another a few days later in St Ives when the warning light appeared again, I got a professional chemical clean when we got home.
From that day onwards (though I can't recall if this happened prior to the cornwall trip), the engine fan has kicked in after every journey of more than a few miles. It stays on for about 10 minutes, as if a region cycle has been interrupted. I've dropped it in to the local garage a few times, no fault codes exist so they've been scratching their heads. I've pretty much only used the car for 40 minute journeys to work, all motorway, since last year so the dpf should be pretty clear, or so I thought.
Last week, during a trip to the south coast, after 90 miles, DPF light came on again. Cue region at the garage, cleared from 35 grams of soot down to 2 grams. Three days later, another long journey of over an hour and a half, and the blocked light comes on again.
Garage now recommending a change of DPF.
Question to all you lovely wise folk, do you reckon the problem lies deeper? Would the ECU be having issues, hence no region cycles really happening? Do I run the risk of a EGR also being blocked? Am I throwing money down a deep deep well in trying to get this sorted, or should I finally say goodbye to the old girl (2014 , 68,000 miles?)
If anyone's had a similar experience I'd be really grateful to hear of how you fixed it.
Thanks.
Get the best trade in or WBaC type offer and get shot imo.

MustangGT

12,301 posts

287 months

Tuesday 23rd May 2023
quotequote all
Get shot and get a car better suited to the low miles you do. A petrol hybrid would seem a likely best fit.

I-A

422 posts

164 months

Tuesday 23rd May 2023
quotequote all
How often is a re-gen required? Is it based on miles? (i.e. a certain amount of soot is generated after x number of miles?)

Smint

1,996 posts

42 months

Tuesday 23rd May 2023
quotequote all
I wonder if the basic issue is the EGR and inlet manifold sooted to hell, is it possible to get the pipe off where it enters the EGR and have a peer inside even if via an endoscope, if the inlet is down to 50% flow only then the car won't run right until that's cleaned out.

legless

1,796 posts

147 months

Tuesday 23rd May 2023
quotequote all
I had a Volvo D5 that had similar issues, a d it turned out to be a sensor problem.

There is a flow sensor before and after the DPF, and the ECU uses the difference in these values to determine how full the DPF is and hence when to run a regen cycle.

Changed the sensors. No more problems.

I-A

422 posts

164 months

Wednesday 24th May 2023
quotequote all
legless said:
I had a Volvo D5 that had similar issues, a d it turned out to be a sensor problem.

There is a flow sensor before and after the DPF, and the ECU uses the difference in these values to determine how full the DPF is and hence when to run a regen cycle.

Changed the sensors. No more problems.
Would this issue through up a fault code?

GeniusOfLove

2,297 posts

19 months

Wednesday 24th May 2023
quotequote all
Tomanybikes said:
Get the best trade in or WBaC type offer and get shot imo.
Best advice you'll get.

Sheepshanks

35,039 posts

126 months

Wednesday 24th May 2023
quotequote all
HSmith22 said:
I've pretty much only used the car for 40 minute journeys to work, all motorway, since last year so the dpf should be pretty clear, or so I thought.
If you're thinking passive regen should keep it clear, then apparrantly VW Group, and probably others too, don't work like that - at least in the UK, as they never get anywhere near hot enough in normal UK use.

Ours is in a Tiguan, and is the newer engine, but the previous one works the same - it should active regen around every 300 miles. Had it happen in ours on a Monday morning doing the school run after a fast 400 mile trip over the weekend.

I guess you need to find someone who knows about these things beyond looking at codes. Perhap a model spedific forum could be more helpful.

TooLateForAName

4,841 posts

191 months

Wednesday 24th May 2023
quotequote all
Check the things that dont always throw errors.

Thermostats, glow plugs, etc. Clean the egr

I've seen dodgy thermostats cause regen failure several times.

LuS1fer

41,765 posts

252 months

Wednesday 24th May 2023
quotequote all
They're fitting DPFs to petrol engines now! To get through more rigorous emissions requirements.

At 25000 miles, my 2018 Insignia 1.6 Turbo started throwing exhaust recycling messages. I've thrown in a petrol treatment to try to head it off at the pass ..

Barrie c 66

208 posts

89 months

Wednesday 24th May 2023
quotequote all
There's a mobile lad on YouTube. O'Rileys Autos who seems to be very adept at sorting these sort of problems out after other people have tried and failed, might be worth looking him up to see if he is local to you.

Biggy Stardust

7,068 posts

51 months

Wednesday 24th May 2023
quotequote all
LuS1fer said:
They're fitting DPFs to petrol engines now! ..
What does DPF stand for?

bearman68

4,795 posts

139 months

Wednesday 24th May 2023
quotequote all
Biggy Stardust said:
What does DPF stand for?
Damned particulate filters?

kylos27

202 posts

105 months

Wednesday 24th May 2023
quotequote all
Give it a run with the dpf removed and see if the engines actually smoking or if it’s just a sensor, if it is smoking you need to sort the underlying problem out then refit dpf

Charlie Croker mk2

290 posts

107 months

Wednesday 24th May 2023
quotequote all
O'Rileys Autos = most knowledgeable guy in uk . Watch his YouTube videos and take it to him to sort out he is in Biggleswade .

LuS1fer

41,765 posts

252 months

Thursday 25th May 2023
quotequote all
Biggy Stardust said:
LuS1fer said:
They're fitting DPFs to petrol engines now! ..
What does DPF stand for?
Yes, I know, PPF then but then you'd all be wondering what it stood for.

Jazoli

9,214 posts

257 months

Thursday 25th May 2023
quotequote all
LuS1fer said:
Biggy Stardust said:
LuS1fer said:
They're fitting DPFs to petrol engines now! ..
What does DPF stand for?
Yes, I know, PPF then but then you'd all be wondering what it stood for.
Its actually a GPF (gasoline) now! wink

HSmith22

Original Poster:

3 posts

18 months

Saturday 27th May 2023
quotequote all
Thanks everyone for all your help.
With a new dpf being a third of the cars WBAC’s value I was a bit torn about getting a replacement. The garage offered another ‘legally grey’ option, that would have meant they’d always have to do the MOT, but when I looked into it, it wasn’t that grey more deep black!
Anyways, next throw of the dice is a removal and sonic clean before I bite the bullet and start looking at a new, petrol (hopefully without a gpf) option.
Thanks again everyone for making my first foray into piston heads territory such a good and informative experience.
Cheers

V 02

2,243 posts

67 months

Saturday 27th May 2023
quotequote all
If you do get fixed, and the car still isn’t driven like a diesel, there is a high possibility that this will repeat itself eventually


Get rid I think, you will find a hybrid car like a Rav4 much better for your usage case and just as nippy as a TDI around town.