206 Hdi Limp mode and black smoke problems

[Paul Baldwin]

Hi,

sorry if this info is all a bit vague but I haven't moved onto ecu controlled cars for obvious reasons!

Neighbours car is randomly playing up so I thought I would take a look at it. Initially ecu light is on and won't rev past 2300rpm ish. After pulling off various sensors and turning ignition off and on, starting and stopping all of a sudden it starts to rev freely.
At this point I took it to give it a GOOD clear out. It goes well, revving to just under 5k, bit of smoke out the back but not loads. I've read that these things suffer badly from blocked egr valves, manifolds and cats hence trying to clear it out.
All was well until suddenly I get plumes of black smoke out the back and the revs hold even when I take my foot off the throttle!!! This was accompanied by a distinct pinking/dieseling noise from under the bonnet. Ended up having to turn the ignition off and then on again which settled it down BUT it has now dropped into a proper limp mode I assume as it's holding 3000RPM accompanied by smoke and missing IF you hold it on the "limiter"
My first thoughts were "shit, it's running on its own oil" but I think it goes too well for that and the turbos quiet.

Any ideas? Will get her to order a cheap code reader asap if that's going to be any help?

Other than that, when it's going right it sounds great and goes well, doesn't use fluids either.

Cheers

Paul.

[Toms306]

2.0 or 1.4 HDi?

And does it hold at 3k or 'jump' around there?

[Poodle]

Yup, you've definitely f*cked it. HTH.





























Um, cheap code readers can be misleading, often to the extent of producing codes that are irrelevant or simply nonsense. If it's the 1.4/6 they're known for chewing through turbos and injectors, the injectors as often as not will be completely swamped with tarry deposits on the head.

[Paul Baldwin]

Hi, it's the 2.0l, only found out last night btw. It holds at 3k but has a constant misfire and smokes if you hold it there. When it was revving freely before the fault came back it was sweet as and pulling really well.

It may be a coincidence but the last thing I unplugged that made a good difference to the running was a sensor at the bottom middle of the injector rail?

Poodle. Don't think I have tbh :p I just provoked the same randomly recurring fault! If it had been running on its own oil because of a bad turbo leak etc it wouldn't have turned off on the key :-)

So a cheap reader deffo isn't worth it then?

Just reading a few of the linked threads at the bottom of the page reminds me. It's also running on, taking a second or so to turn the engine off after you've turned the ignition off.

[Toms306]

Ah the 2.0 is slightly better for us as the smaller ones didn't come in the 306s lol.

The sensor under the rail is rail pressure, it usually either works or cuts the engine though. Your fault sounds more like the regulator (on the HP pump), especially with the running on as well...

A cheap reader may be of some use, but not often!

[Paul Baldwin]

Ok ta, will investigate more at the weekend

[Poodle]

Haha yeah i was just messing. Certainly doesn't sound like it's running on it's own oil from your description. As Tom says, start with the regulator. Failing that there's quite a few things listed in the link in my sig.