Hmm ... After 44 pages, have we got any kind of likely single answer / small set of answers to this, or is it different for each car? Do I need to go get it plugged into a diagnostic machine and then fumble in the dark from there on out? IE is it a particular part going wrong that's common to all these stories, or is it the
's default response to any error condition?
1.5 Dci 80,
/housing/intake pipe cleaned of all their carbony crap, two new relays dealing with preheat/start and cooling fan circuits, clean air filter in place, changed
filter and replaced jet-black ichor that was was previously filling its veins with five-ish litres of pure clean 5w40 fully-synth PD-spec... and disconnected the battery twice for more than a half hour each time...
And it still happens.
It's not as dramatic as some people's experiences here, but it's still potentially problematic and it points to something being wrong. The engine seems to run absolutely A-OK apart from when some electronic part goes on the fritz and decides to wrap everything in cotton wool.
Whatever the source is, it seems to be related to power demand; if I ask more than roughly half power (40hp, enough for 85mph on the flat but far less uphill) for an "extended" period (about 15-30 seconds, these are UK roads we're talking about :D) then the light comes on and the car appears limited to the aforementioned half power. It's sufficient to just about keep up with traffic and torque isn't as affected as power, but the driving experience is much like you'd expect a five-door hatch with a 734cc turbodiesel engine to be... unpleasant and uncertain.
Cruising just below the trigger level doesn't have any effect. Pressing on with foot flat to the floor tends not to trigger it, but will occasionally do so. Weirdest of all, it can be cleared by declutching and letting the revs drop below 1500, and sometimes it will eventually clear after some time spent cruising very gently in the 1500~2000 range.
Driving in almost all other situations is completely normal, except it occasionally seems to suffer what my dad calls "sticky wastegate syndrome" - the
randomly doesn't spool until noticeably higher revs than expected (1250~1500) - sometimes 1750, sometimes 2000~2250, thus robbing the engine of a great deal of performance below that speed and suddenly surging forwards after. Other times it seems to boost more than it should, at least going by the noticeably increased wooshing noise coming out of the passenger footwell. The two symptoms may or may not be related, who knows?
Also there is an occasional "cough" from the engine, like a violent misfire, when running at lower speeds and throttle loads. I have changed the fuel filter (not had chance to examine the old one yet) and, after a hell of a lot of priming (still with air bubbles in the lines?!) the problem is much reduced, but not completely gone.
It was manifesting more when fuel was low and reduced after topping up, but I'm now nearing the point of the reserve light coming on and it's still only happening quite rarely, when letting it run this low would have rendered the car near-undriveable before I changed the filter.
Again this may be unrelated, but more data points for the diagnosis...
Extra ~ The problem still manifests with the
valve plug disconnected, so either the solenoid is completely dead (or the wiring's had it), or it's not having any influence in the matter. (no probs Tahrey