407 very intermittent surging

[moizeau]

Yes please Elis. I can see the problem with the oil prior to the change but it should be OK now? Have just re posted them with a better resolution.
Thanks

[EDC5]

Here we go:

One thing to remember is that you have a different injection ECU to mine, you've got the Siemes and mine is the Delphi. Not sure what difference that would make.

And yes, with all of that new oil the oil pressures should be a lot better but damage could have been done in the past by the low pressure.


From your pics it looks like your ECU is currently attempting a regeneration, it would be interesting to take it for a drive now for about half an hour at reasonable speeds to see if it completes it's regeneration.

As we can see from the soot loading on mine, 78%, my ECU will attempt a regeneration soon; not surprising as I've driven 544km since the last one.

[moizeau]

It was on regen before I took it for a drive for 30mins all above 2000 rpm, locking it into a low gear if necessary to keep it there, still on regen?
I shall compare our screen shots and see what is different. Thanks

[GiveMeABreak]

I take it this car hasn't got a particulate filter ECU because it shows as not present.

It's actually referred to as a Fuel Additive ECU, which were separate on earlier cars. This operation is now handled by the Injection ECU, so any data relating to that part will be found nested in there.

[moizeau]

Thanks Marc, no red herrings there then

[GiveMeABreak]

[moizeau]

Just compared your figures Elis, there are several differences in the way they are shown, mine doesn't mention how fluid is in the tank. Everything else looks similar apart from my particle filter soot load is up to 88% and is still showing it's status as 'regeneration'. This is after the missus did a rund trip of 30 miles to the shops. At the bottom of the page it shows degree of filter soot clogging as 69% and particle filter load state as' filter in correct state' I would try a forced regen but it sounds a bit brutal.

[GiveMeABreak]

The system is designed to regenerate only when needed and a forced regeneration is not recommended under normal conditions because of the strain on the components. If a normal regeneration cannot complete, the ECU automatically makes a note of this and the number of attempts to undertake the regeneration cycle.

It will apply different strategies in order to complete the regeneration cycle until it has completed. When it fails to do this after a number of attempts it will then put the depollution light / particle filter clogged message on. That’s really the time to do a forced regeneration.

[EDC5]

It just seems strange that the status of your ecu say 'Regeration' but if all is well then I wouldn't bother.

I think 'degree of clogging' refers to the crap in the DPF that can't be burned off and basically corresponds to DPF 'lifetime', yours being 69% of it's useful life used. I would assume that regenerations become more frequent as the clogging increases as there are effectively 'dead' areas in the DPF where no soot trapping can take place.

Yes, Marc is right. The forced regen does seem brutal and if everything is OK I wouldn't do it.

[GiveMeABreak]

Yes, it’s the Cerine in the additive that can’t be burnt off, so this remains in the filter over time until it is cleaned out properly or replaced with a new one.

[moizeau]

Just been for a drive into town to try and get the AC charged and a chip in the windscreen fixed. A round trip of 40 miles with good A roads. Accelerated hard past a couple of cars, eased of and it wasn't a surge but more like the revs dropping off and then picking back up. I used the manual stick to keep the revs up above 2000 and kept going to see if it would clear. It did, so did another 10 miles enthusiastically. When I got home, plugged the 'puter in. Soot is now at 2%. It still says it's in regen mode but possibly because it hadn't finished completely? Thinking about it every time it's 'surged/dropped revs' it's after it's got nice and warm and following an acceleration. Perfect scenario for a regen I would suspect? I wonder if it is struggling to regen? Time will tell but at least I now know a little more about where to look in Diag for clues. If it surges again I'll check the soot content. If nothing else it eliminate it from further inquiries!
Cheers for the help so far

[GiveMeABreak]

Normally when the engine is running at normal operating temp, it is sufficient to allow regeneration to naturally occur without much or any assistance Pete. The issues really are when it gets to temp and then decides it needs to do one, that invariably if the engine is stopped and a few short trips after, it won't get the chance to complete and then has to try again later and if it doesn't get the chance then it engages regeneration using the consumer devices to increase engine load, like the heater rear window and the glow plugs etc., to get the engine to temp as soon as possible.

[moizeau]

I did notice that it has been getting up to about 92 very quickly. Following the regen, it takes it's time and seems to run cooler so that makes sense. With the altering revs, maybe it's trying to regen with the revs too low? I'll be keeping an eye and an ear on it. Cheers

[moizeau]

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?

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'.
This is obviously not normal behavior but I'm lost at what could be causing it. I am, however, convinced that behavior, or rather misbehavior, occurs during a regen. I will be continuing to monitor soot % and have set the trip to zero.
I was told the Eolys was topped up recently, how could I check physically and what should the Diag figures be? It's going to Lyon and back in a weeks time, all in one day (hopefully), so I will also take readings before, on arrival and after. It will be interesting to see what the results are.
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

[MikeT]

Regen from 67% or more down to 2% is good and perfectly normal imo, Pete. Can't say why Diagbox reports it's still in progress.
Either way, I doubt it's related to the surging you describe.

Maybe you could snapshot live data when the surging occurs (I'm sure Diagbox has the capability, though I can't advise further I'm afraid as it's not something I've attempted yet). Perhaps focusing at air data and related, duty-cycled valves for instance?