Smoke from DS DS5 Diesel engine after a short run

[Donkey]

Hi,
I have a DS DS5 powered by a 2.0 BlueHDi 180 diesel with a 6 speed auto. It's a 65 plate with 17k on the clock. I got it three months ago and have put 3k on it. It does regular short journeys and as such doesn't get up to temperature. However it often gets good long runs at speed, the last being 500 miles over Christmas, up to Aberdeen and back. I've always filled it up with Shell V-Power Diesel and the service book is up to date. I'm aware of the potential problems relating to the DPFs on the Euro 6 engines wrt short trips, and regularly drive longer distances so it has the opportunity for regeneration.

Today I went on a short urban run of about 3 miles (10 minutes) to the supermarket, and back home again after about half an hour. The engine temperature gauge didn't even register any heat on either part of the journey, which I have found to be the norm. When I came back and turned into my driveway I could smell burning, just like you get when lighting a barbeque using lighter fluid. I stopped to reverse and saw alot of smoke from the rear of the car. My driveway is quite tight to turn round so it takes a few movements to turn fully. Each push of the accelerator gave off more smoke. I stopped and revved it again - lots more smoke, a kind of white/grey colour coming out of the exhaust. I checked the dash, no warning lights or messages or fault indications. Temperature guage hadn't even registered any heat (it's a digital one) and AdBlue level was sufficient. Revved it a few more times and more of the same smoke came out. With the engine still running I opened the bonnet and the smoke smell was in there. I revved the engine again and could see and smell the same smoke coming from behind the engine block. Checked under the car and could see nothing escaping from the exhaust. I took the cover off the engine for a better look and could see nothing untoward, no obvious leaks. Coolant level was normal and the oil level too, although I did notice a few bubbles on the oil on the dipstick. I also found a little bit of mayonnaise under the oil filler cap. During this time the radiator fan came on and the temperature gauge had risen to 60 degrees. Despite all of this, the engine sounds like a diesel should - no knocks, is steady and quiet (for a Diesel) and performance prior to this was as expected.

I'm thinking a few things here:
First being that I've interrupted it's DPF regeneraton procedure. However, it was nowhere near up to temperature and hadn't got to the desired speed - I might have just hit 30 mph briefly after a cold start under urban driving conditions. Although I'm not altogether familiar with the Euro6 Diesel workings I'm sure a DPF regen won't have started under the above conditions. And surely there shouldn't be any smoke / vapour anyway.
Secondly, I've got water ingress into the engine block ie cylinder head gasket failure (I hope not), taking into account the white/grey smoke and mayonnaise under the filler cap.
Thirdly, could the mayonnaise under the cap be due to the short runs? Any moisture in the engine hasn't had a chance to dissipate so it's collected at the highest point?

Has anyone else experienced similar? Does it just need a good run (which I was planning to do tomorrow) or does it need a visit to the Citroen garage before I do any damage?

Thanks in advance

[GiveMeABreak]

As for as the DPF part of your query goes:
The Engine ECU and the BSI records details of the last few trips and whether it has been able to regenerate or not and will apply a particular programme to regenerate when the conditions for that profile are met and it will keep trying until it fails - and then when the soot gets loaded, the sensors will detect the pressure differences going in and out and you'll get the message on screen if it can still not regenerate. That's when you need to go for a run at over 40 MPH for 15-20 minutes when engine is at operating temperature.

The Ad-Blue is completely separate and is for the SCR - that gets injected into the cat, whereas the DPF additive gets injected into the fuel tank. As the AdBlue is just Urea, that shouldn't smoke in the burning sense.

It is quite possible to interrupt a regeneration - if you notice a little smoke or vapour just leave the car to idle - don't rev it. It will finish the cycle if this is what it is doing. The only way to see what the record is and the state of the regeneration and whether it is having issues with the cycle is to get it on a Diagbox to see what the status is.

[Donkey]

OK, so the car effectively learns as it is driven and regenerates based on what it has learned. When I revved it I only took it to about 2k, nothing more as it was still cold

The worry I had/have is the amount of smoke that came out of the exhaust and that there was smoke coming from the engine bay at the same time. I've not come across this before but then again a Euro6 engine is still new to me.

[lexi]

There is heat produced in the air filter on regeneration.

[wurlycorner]

No experience with these, but just from a 'ignorant consumer' perspective, it doesn't sound right that a car should be generating smoke like that by design, surely?!
That sort of thing is just going to get constant questions and trips to the dealer under warranty, from every owner?

[TallPaul73]

This has just happened to me Ds5 150... smoke coming from back of engine but no other issues. Did u find the cause? Was it an interrupted regen?