308 HDi emission fail

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nikeastwood
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308 HDi emission fail

Post by nikeastwood »

our normally very good at MOT 308 HDi has failed its MOt at the diesel emissions test, its a visible smoke test and you can hardly notice it.

car is regularly serviced, has the original cat/dpf in good order no engine light or depollution faults and the car is good on fuel.

car hasnt been used as much recently, but the MOT test place was about 6 miles away along country lanes so engine was nice and hot

now, what can I look at? any additives? a decent motorway run before I take it for retest [he said he wouldnt log it on, test it and see how it does]

turbo is good, all pipes seem to be fine, it pulls good and smoothly.

I have half a can of EGR cleaner/intake spray, I might blast that through it, double check its pipes, and take it on the moroway for about a 20mile trip before taking it immediatly back for a rest on monday

any tips? fire away.
nikeastwood
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Re: 308 HDi emission fail

Post by nikeastwood »

right, some extra info.

I plugged the car into my Delphi VCI, I do have PP2000 and Diagbox, but find it irritating to use, so my Delphi Clone is the thing I turn to to diagnose general running issues and to test actuators etc.

I had a code for "too high airflow", cant remember what the code was, I cleared it. But anyway it can relate to the EGR being stuck and airflow not being right.

Using the live data, we took the car for a drive from cold, and observed the EGR function, it was opening at part throttle, and idle, and closing when power was needed and this was correct. We did a variety of roads and I have no reason to suspect the EGR really as it was functioning well, and as it should.

I rescanned, the code didnt reappear for the high air flow.


I dont think the car has ever done a regen, its additive tank was estimated to be at 61% and it was at this level a couple of years ago!, how can I find out if it has ever done a regen? in diag/PP2000?

some hard revving saw the exhaust throw out some soot, but I did actiave the additive pump via software so that may have added some to the fuel before we did our test trip.

I have a friend who has an MOT centre, he said to "just thrash it at high revs for a bit", I will try that on sunday we are going to wales for the afternoon.

have also bought some Wynns Diesel Particulate Filter Cleaner, to add to the fuel before we go. I work nights and Monday morning after work I am going to take it for a drive and go straight back to MOT centre and get it on the test while engine is hot.



also noted, at previous MOTS, they have held the revs at a constant high revs [4000?] while doing the test, but today they just revved it up a couple of times, which of those tests is right?
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GiveMeABreak
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Re: 308 HDi emission fail

Post by GiveMeABreak »

If you go into the Engine ECU on Diagbox it will show you lots of info including the regeneration status, distance between regens etc.

I can't see what benefit operating the additive pump via the diagnostic will do to be honest apart from checking it is actually working :-k reason being is that each time you add fuel to the tank, a metered dose of additive is also injected into the tank. This means the fuel mixture already contains additive in it.

Don't forget that natural regeneration will occur on good runs when the exhaust gasses react 550 °C. Assisted regeneration will only take place when the filter needs it and the exhaust gasses are not normally hot enough. If the filter was becoming blocked you would of gotten a message / warning before now though.
nikeastwood
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Re: 308 HDi emission fail

Post by nikeastwood »

passed

a good ragging plus some additive in the fuel got it through.
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Huskyxantia
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Re: 308 HDi emission fail

Post by Huskyxantia »

Well done , got a bit worried reading this theres me thinking hello is this the start of many more hdi engines slowly fail8ng mot and being scraped.
nikeastwood
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Re: 308 HDi emission fail

Post by nikeastwood »

I also have a 207 110 HDi, but it has had the EGR and DPF mapped out of it, sailed through its last mot.

next year, I will just give the 308 full beanage for a day or so before I take it for test, what seemed to clear it wasnt just a long run, but just letting the engine rev much higher in each gear than normal driving would, as diesels are quite relaxed when it comes to revs as you dont need much rpms to get power.
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Huskyxantia
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Re: 308 HDi emission fail

Post by Huskyxantia »

nikeastwood wrote:
28 May 2022, 21:05
I also have a 207 110 HDi, but it has had the EGR and DPF mapped out of it, sailed through its last mot.

next year, I will just give the 308 full beanage for a day or so before I take it for test, what seemed to clear it wasnt just a long run, but just letting the engine rev much higher in each gear than normal driving would, as diesels are quite relaxed when it comes to revs as you dont need much rpms to get power.
Did you map the egr ,dpf yourself? Is this easy to do ? Sounds interesting
nikeastwood
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Re: 308 HDi emission fail

Post by nikeastwood »

hi, I got somebody from facebook marketplace to come and do it who does remapping, I bought the 207 with faults and it had a blocked dpf, I bought a new dpf for it but when I dropped the old one out the cat had been removed by a previous owner, and the dpf had a hole through it. I put my new dpf on but it blocked within 200 miles, and that was because there was no cat to burn off excess deposits before they get to the dpf.

So I bought an older 207 cat only pipe to replace the cat/dpf pipe I had, its a straight swap, I fitted an EGR blanking plate and then had the egr and dpf [with additive etc] mapped out, I kept the power map the same because to have it mapped for more power, will always mean it burns more fuel, and I didnt want that.

cat , and cat/dpf only pipe side by side:
2021-10-09 13.21.14.jpg
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Huskyxantia
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Re: 308 HDi emission fail

Post by Huskyxantia »

Looks very interesting and a much happier car by the sounds of things , blocking up after just 200 miles is a shocker !