Particle filter at risk of blocking and p0238 fault code.

[frogdr1ver]

Hi there,

*****Have updated the title to reflect the latest issue, please see the end post.*****

Ive got a 2008 C4 Grand Picasso 1.6 hdi thats done 110,000 miles or so. When its cold first thing, it quite happily revs, boosts and changes gear no issues. Once its warmed up it feels like its not boosting properly, the revs go up but with a lack of power, if you manually tap the gearshift it will change up and once it get settled it will carry on changing fine.

It tends to be worse if you need to do a rapid acceleration from a standstill such as heading across a roundabout. It was really bad for a while (almost undriveable) and i blanked off the EGR valve which cured it for a week or so then its been the way it is now since then.

It had a new turbo early last year and a new clutch late last year. Ive used diagbox to scan it and its not showing anything up other than P0401 air flow higher than recommended. Cant see any obvious air leaks, vacuum leaks. Vacuum pump is sucking fine.

One thing i was confused about today i started the engine, turbo vacuum solenoid pulled down as it always does, i removed the inlet to the vacuum pump expecting the solenoid to lift and it didn't it just stayed there. Is that normal as i thought the vacuum would keep it held down?

Any advice on where to look next would be much appreciated.

[GiveMeABreak]

Hi and welcome to the Forum

This sounds like it is the MAF - this chap had the same symptoms as you, but had the everything replaced apart from the MAF and guess what... it was the MAF! Have a read and you might save yourself a few quid and a lot of stress

http://www.citroenpicasso.org.uk/picass ... uit-fault/

[frogdr1ver]

Thank you, id wondered about the MAF before but kind of thought that fault would be caused by the EGR being blanked off? What sort of prices can you get MAF's for? GSF are doing them for £100 with discount at the moment, is there anywhere else you would recommend?

[GiveMeABreak]

Send me a Private Message with your VIN and I'll check the correct part for the MAF for you, as we really need to make sure you have the right one.

[GiveMeABreak]

OK Euan, the part number for the MAF (or Flowmeter as they call it) is 1610874680. The PSA part number is 1920 GV.

Here's a listing for one on the bay:
http://www.ebay.com/itm/CITROEN-BERLING ... 43e75149df advertised for £79.

You could try and clean your old one up with some special MAF cleaner first to see if it makes any difference, but this is the part if you think it's likely to be the MAF.

[frogdr1ver]

Much appreciated, i see thats the delphi one as well. Did buy a cheap egr valve from ebay recently, caused chaos with the computer so was removed and sent back! Ive had a look at the MAF when ive stripped it out before, whats the success rate of the cleaning fluid?

[RichardW]

Is this an EGS car? It sounds like it's not changing up unless you force it? Is the EML on? The EGR valve on ours (manual) kept causing the handbrake light to come on! If it is EGS and is not changing gear, then I doubt it's the MAF....

[frogdr1ver]

It is an EGS car, no EML on, changes fine 90% of the time no problem at all especially when cold. When i put the cheapo EGR on it caused the handbrake light to come in which was bizarre. Thats been removed and the old one put back in and blanked again and no warning lights. It wont change at times as the revs dont come up enough or quick enough like a lack of power/boost

[RichardW]

The EGR / handbrake thing is a particularly cunning piece of progamming - the action of certain EGR faults is to disable the auto handbrake - but not set the EML! I changed the brake light switch and underbonnet fuse box and spliced some wires behind the battery trying to cure the handbrake light, before I eventually found a fault description that said the EGR disables the handbrake! Changed the EGR and no more handbrake warning....!!

The air flow fault is probably due to the EGR being blanked - it would be expecting some recycle of air, so if there is none, then the fresh air flow will be higher. If you've got Diagbox, then you should be able to check what the air flow is doing when the engine is running - does it rise smoothly when the engine is revved? With the engine off, push down on the turbo actuator and check that it comes straight back up. If the air flow checks out OK, then the vac solenoid for the turbo (which is tucked down the back of the engine!) is another common fault point. I would also check the differential pressure across the DPF in diagbox - is it high; especially when engine is revved?

[frogdr1ver]

I'll check those readings over the weekend, the vacuum actuator that opens the IGV's on the turbo stayed pulled down when i removed the inlet to the vacuum pump, is that normal? I would have thought that the vacuum would have been lost? Is the vac solenoid home replaceable if it turns out to be that and any tests that can be done on that?

[frogdr1ver]

Thought id do an update on this, the latest issue ive had is the "diesel particulate filter at risk of blocking" warning is now on. I forced a regeneration but that failed (filter is at around 58%), when i looked in diagbox it said it had been trying to regen every 250 miles (poss km) and could not complete it. I suspect thats to with the egr being blanked and not getting up to temp.

I had also removed the egr butterfly valve from the air doseur to see if that was causing the intermittant power issue at pull away, which it wasnt (unfortunately). Also getting an occasional turbo over pressure warning as well.

Ive got a used air doseur from ebay to fit when i get home and want to replace the egr to try and sort out the regeneration

Can anyone link me to the correct (and reasonably priced) EGR Valve please? I have enquired about this one http://www.ebay.co.uk/itm/141821312695? ... Tags=bu=bu and they say it is correct but the last egr i got caused chaos with the car so was sent back and refunded.

thanks in advance

[GiveMeABreak]

That one in your link is not the correct one - the part number I gave you in the last post (1610874680) or 1920GV is the one listed for your car.
Some links:
Used £25
http://www.ebay.co.uk/itm/Peugeot-207-2 ... SwZ1BXdk2q

Both the part numbers are listed at the end of the listing page - New £50 12 mths warranty
http://www.ebay.co.uk/itm/MASS-AIR-FLOW ... SwHnFVygIh

New £93 (note that warranty is 12 months, but limited to exchange, replacement or repair
http://www.ebay.co.uk/itm/AIR-FLOW-MASS ... SwPhdVGoR3

So here's a few choices to be going on with.

[frogdr1ver]

Hi Marc,

Its not the MAF im after (i bought the one from your original post) its the EGR Valve im after now.

[GiveMeABreak]

Can you PM your VIN again and I'll get the part for you

[frogdr1ver]

Thats great thank you, PM sent