407 very intermittent surging

[moizeau]

Cheers Mike, I'm sure this going to be a bloody sensor or electro valve somewhere. I've also no idea why Diag hasn't reported it as inactive unless something is fooling the system? I'll plug the 'puter in and run live data in another 250 miles when a regen is due-ish. It only does it when it's regenning as I can see, or just before? The last twice when I've driven through it and plugged in, it says that the last regen was done 0 kms ago.
Thanks again, I'm sure I'll be keeping you posted.

[moizeau]

Right just found something interesting and going to check. In one off my very early posts about this I mentioned these pipes thinking they were vacuum pipes for the CC. Could someone with more knowledge than me read through this post on the Peugeot forum and see if it makes sense please
https://www.peugeotforums.com/forums/40 ... ng-191082/
Off to find a straw, also this should show up on an actuator test I would think if I can find it?
Back soon
Cheers in advance

[GiveMeABreak]

Firstly I've come to the conclusion that it's not surging, but dropping the revs down to idle before picking back up.

I've been keeping my eye on the % off soot in the filter. Yesterday it was up to 67%. The last time it regenned it dropped to 2% but the status stayed at 'regeneration', I presume because it hadn't finished?

The percentage of soot is only an estimate Pete using the sensors - it can't be 100% accurate and as soon as a regen has occurred, of course you will start accumulating soot again until the next regen kicks in.

Today it started playing up again, dropping off before picking back up. Quite dangerous to drive if in traffic!. I carried on driving and held it in 4th to keep the revs up. There was a change in exhaust note (as if it was blowing and a hot smell) Drove through the 'dropping off' and then continued for a good 10 - 15 mins all above 2000 rpm. Got home, plugged the 'puter' in, soot now back to 2% (again), not 0, and the status still remains at 'regeneration'.

That hot burning smell and noise is very likely the regeneration cycle kicking in.

I was told the Eolys was topped up recently, how could I check physically and what should the Diag figures be?

The amount of additive in the tank is only an estimate Pete. It is calculated from the quantity added at new and then by the amount the computer has injected since, but is only an estimate - there is not physical device to measure the volume in the tank. The only way is to visually inspect it and that usually involves removing the additive tank and physically emptying out and measuring the quantity. We also are assuming that whoever last topped up the tank managed to reset the additive level in either the additive ECU (if yours has one) or the injection ECU afterwards.

One other thing, what could I monitor on Live Data regarding different sensors, egr, turbo, pressures etc and what should they be? This is getting way beyond my knowledge, but I'm very willing to learn, though would rather not have to!
Cheers all in advance

If I recall the car was stored for rather a long time - maybe it will take a while for a good clear out of the system after standing for a while. I doubt the additive level is the issue - as it reports it has cleared the soot down, so must be regenerating - it's just why it is not telling you it is completed. In Diagbox, you should be able to run a Global Test, then after that, from the ECUs listed, select the Injection ECU and confirm. From their you should be able to see all sorts of information regarding the status of the filter, the soot loading, average miles / KMs between regens and other info. If you snapshot some of these screens using diagbox or print screen and post up the shots, maybe we will get a clue as to what is or isn't happening.

PS - I'm just clearing away the foam lance from washing the cars and then will get you the info re the lamps..

[EDC5]

Right just found something interesting and going to check. In one off my very early posts about this I mentioned these pipes thinking they were vacuum pipes for the CC. Could someone with more knowledge than me read through this post on the Peugeot forum and see if it makes sense please
https://www.peugeotforums.com/forums/40 ... ng-191082/
Off to find a straw, also this should show up on an actuator test I would think if I can find it?
Back soon
Cheers in advance

The post on the peugeot forum is talking about the double-doser unit that you car might have that can bypass the intercooler when regerating.



So basically one flap closes and the other opens to bypass the intercooler. Each flap has it's own vacuum solenoid valve. If one of these fails shut then when the ECU closes the other one both will in fact be closed, choking the engine.

[moizeau]

Thanks Marc and Elis, Elis that is exactly it. And the ecu sees a problem and opens it again, dropping off revs then returning. Just pulled the pipes of the electrovalve end, 2 on the lhs and 2 on the rhs. 1 pipe on each side is marked with a green clrcle, this is the one that moves the throttle body flaps and they are quite a loose fit. Do the pipes just pull off the throttle bodies? It looks like they do from your photo Elis. If so I can blow down the other way to check for a leak where they connect to the valve. I'm guessing the throttle bodies can be checked on Diag also with the engine running. If so it would simulate the issue. Just off to try and find a bit of pipe to make a better fit and the valve end. Don't want to starrt cutting anything yet.
To be continued...

[GiveMeABreak]

Your part is 0345F0 Pete - here's one at £55 for a Magneti Marelli one in case it's faulty:

https://www.ebay.co.uk/itm/Air-Doser-Fo ... 1397953456

[moizeau]

Right, fitted new extensions on the valve end, so they should be sealed. From your photo, Marc, I see the butterflies are visible, going to expose them then suck from the valve end. I can hear them moving when I did it earlier, but I don't know how much. I also don't know if I've got enough suck to operate them fully. Although the pipes should come off the throttle bodies, they really don't want to and I don't want to force ( and break) anything. The next thing to check would be the electrovalve, any ideas on that?
Thanks for the link Marc

[moizeau]

Just exposed the butterflies, the pipe on the rhs operates the top one, and the lhs pipe operates the oily beast. I haven't got enough suck to fully operate them, but they both move the same amount, they also seem to move freely against the spring. So it just leaves the electrovalve to check, or it is in fact the poor fitting.
Would these butterflies bypass the IC if you were in perfect regen conditions? I.E long motorway stint.
It would appear each butterfly has it's own electrovalve. One is mounted on top on the other but the other way round.

Thanks for headlamp nos. Marc.

[EDC5]

Yes, each butterfly has it's own electrovalve as far as I am aware. If your flaps are malfunctioning there may be an issue with:

Vacuum supply to both electrovalves from the main vacuum system (pipe split)
Vacuum tube between each electrovalve and it's respective butterfly valve.
The electrovalves themselves.
The butterfly assembly and return springs.

As far as I know, one should spring shut and the other should spring open... is this the case? You may have to remove the whole item for a proper look.

[moizeau]

Cheers, yes ,one's open and the other shut, The pipes between the valves and butterflies are good now and the butterflies move smoothly against the springs, so it should be good. I'm going to have a look in a bit if I can check the movement using an actuator test.
If it was the main supply then it wouldn't cause the 'starving of air' because if it can't shut one then it can't open the other. I'm guessing that if the problem persists then one of the valves isn't triggering the butterfly, electrical connection or mechanically inside. If the former I would expect a code. Possibly need to wait and see what happens at next regen?

[EDC5]

You could try disconnecting the vacuum hoses from the butterfly valves and see if that sorts it. Remember you will need to seal them to prevent a vacuum leak.

It sounds like when it tries to do a regen it closes one flap but fails to open the other for whatever reason causing the issue.

[moizeau]

Yes, that is what I'm thinking, the hoses really don't want to off the butterflies and I don't want to break something that may not be broken. I may have a look for a couple of hose clamps or even doubling a part of the rubber hoses and cable tie them after releasing any vacuum at the electrovalve end.

[MikeT]

Would these butterflies bypass the IC if you were in perfect regen conditions? I.E long motorway stint.

The butterfy that bypasses the IC (called inlet air heater throttle) is used for regeneration purposes, yes. It's dynamically controlled to temper the intake air temperature.
The other butterfly is the EGR throttle.

[moizeau]

Thanks Mike, Just to confirm that I'm understanding it correctly, the oily beast at the bottom is normally closed (ignition of) and the comes from the intercooler. Under regen the top one would close and the bottom one open forcing warmer air in to assist the regen? It was the pipe that actuates the oily beast that looked suspect, so if that stayed shut and the top one is then closed to assist regen that would cause my issue? Didn't know anything about this system a few hours ago, slowly getting some of it round my head with all the help available.
Thanks

[EDC5]

I wouldn't think too hard about it to be honest, just pinch both of the pipes off to prevent any butterfly actuation and see if the situation improves.

The whole intercooler bypass system seems a bit daft to me. My RHR engine only has the single 'EGR Throttle' (without intercooler bypass) and it can regenerate the DPF just fine.