DPF cleaning using liquid cleaner

[studio500]

Hi All
Our recent purchase of a Meganne 1.9DCI has also brought with it the dreaded FAP regeneration problem.

Afte only 1 week of use the problem arose and despite a long journey from the Midlands to Cambridge only last week, the car has started to under perform with the familiar wooshing sound that preceeds the Regenerate FAP display on screen.

I have therefore decided to go down the DPF cleaning route using one of those cans of readily available DPF cleaners. I don't know if this is a wise move or not but I'm willing to give it a go, especially as the MPG on the car has now dropped to sub 30mpg.

My question is, the can says to remove the pressure sensor or similar probe on the DPF. I understand that there are a number of probes before and after the DPF cannister so to speak, but which one is the best to remove and is this done underneath the car, as I have seen some manufacturers engines on youtube where the probe is removed from inside the engine compartment?

Any thoughts would be very much appreciated

[triumph2.5man]

Hi, exactly which model and year of Megane do you have?

[studio500]

Hi,Apologies for the delay, health is something that's not on my side lately.

It's the Wifes car and it's a 2005 Scenic privelidge 1.9dci (130 E4)

I've booked it in with a local garage but if it's pretty accessible I would do it myself.

Another niggling problem is sometimes the fan doesn't work on setting 4 or 5 9 (can't recall exactly which number) according to the wife and so takes a long time to defrost or de-mist but I'm more concerned with the atrocious fuel economy and the wooshing noise when the FAP appears full.

We also just had an orange service light suddenly displaying on the dash too.

Many thanks

[studio500]

I think the guy who we bought it from knew about the problem because on the test drive he said, "with these cars you have to take it on a run every know and then or a FAP warning comes up".

Also as we pulled up outside his house he was just pulling up in the car itself as if he had just taken it on a run.

Just my thoughts.

[triumph2.5man]

Thanks for responding (you would be amazed how many people don't!)
I was hoping somebody else would reply but it was not to be. What I know about FAPs or DPFs can be written on the back of a postage stamp. As far as I am concerned FAPs are bad news and just something else to go wrong and what you have written confirms my opinion. I have avoided FAP-endowed cars like the plague. The way things are going, diesels will soon be banned anyway, FAP or no FAP!

I am not an expert on Scenics but I note that your car fell foul of Euro 4 introduced 2005. As far as I know this did not include the 1.5dci (our mark 3 1.5 2009 does not have a FAP thankfully).

I have been consulting my Megane Haynes manuals (I do not have Scenic ones). The mark 2 up to 2005 does not mention FAP at all. The mark 3 does not cover the 1.9dci engine but does mention FAPS. Basically it says what you already know - regeneration is automatic. Urban driving does not help but a fast 20 mile run at 60mph is recommended. No interval (time) is given for such a run. There is pressure and temperature sensor on the FAP but not known if accessible from above or below, probably the latter.
There is a caveat that if the filter is allowed to block because of excessive urban driving, regeneration might not work and it sounds as if this could be your position. Give it a try with the fluid - I would.
Sorry I can't be more helpful. Perhaps another member could give an opinion.

Mike

[studio500]

Thank you Mike for taking the time to reply and the investigation that you kindly conducted on my behalf.

I have read similar problems as those that you mention, I've even read some instances where owners have had the FAP can cut open, the insides removed and the can welded shut again, but I do not know what this effect this would have upon future MOT testing.

In all honesty I wish I had known this before purchasing the vehicle as I would most certainly have gone for a 1.5DCI instead.

I'll take a look under the car this weekend and report back on my findings as it may benefit other members in the future with a similar problem.

But once again, thank you for your kind input and patience with my response time.

Your help is very much appreciated.

Marc

[Cliffyboyd]

Hi iv removed my dpf innards and had software removed/re mapped for 220 quid ,best thing I've ever done ,more power ,better mpg,46mpg instead of 41 ,does not effect emissions test ,just had it mot'ed flew thru .

[triumph2.5man]

That's very interesting Cliffy. I wonder how Marc, the original poster, got on? We have not heard from him for over 2 weeks. I thought afterwards about having seen clips on Utube where DPF is removed and washed with a pressure washer - with good results apparently.
Did you have the guts of the cat removed at the same time?
At least with the Renault system, that awful, toxic eolys fluid is not used as in the Focus and the PUG!

Mike

[Cliffyboyd]

Hi ,no my cat remains untouched,I cut a big hole in my dpf ,smashed out all the brittle inards,put them in a bag,which got me £ 50 off software/re map price.
The cat does the emissions bit,but the dpf collects soot particles,and if like me you do short journeys the dpf will block up all the time ,the best solution to that is thrash the arse off it down a duel carriage way for a bout 30 to 40 miles ,I was constantly getting check injection on my dash ,I'd take it out thash it ,warning would go off,but after a few years it reached its maximum re gen limit ,so i took drastic action and removed it ,iv never had check injection since ,fuel consumption is much better .
Incidently the size of the holes in the dpf is ridiculous, no wonder they block up ,modern diesels are not designed for short journeys, the dpf needs to get hot enough to burn the soot ,it turns it too ash.
Check injection can also be caused by the glow plugs ,even thou they are only used on start up ,apparently they are constantly monitored .
Iv also heard of people just putting a brush handle through dpf to smash them out,no need to take apart and weld up ,do not remove dpf inards without software removal as well and also leave leave dpf body and sensors ect in place so they pass vehicle inspection
Cheers

[Cliffyboyd]

I'd just like to add another common fault with dpf's
Either end of the dpf is a pressure sensor,they measure the pressure difference between front to back ,they have a thin rubber pipe going to them ,its common for these pipes to split causing check injection ,happened to me ,iwas advised by my local garage to buy new dpf !!
Very simple to fix as you can imagine.
Get your self a Renault specific code reader ,mine cost £ 90 ,has paid for its self times over

[triumph2.5man]

Thanks for that Cliffy. I could never maintain my Renaults without CLIP! Cheers,