All,

Something worrying happend to me twice now so thought I'd seek the combined might of knowledge from this forum.

Basically I have the 4.4 SDV8 and, on occasion, like to experience the performance it offers. I have to say I still find it quite impressive that a 2 1/2 tonne shed can accelerate the way it does to overtake on motorways etc.

I have had a couple of occasions however, while accelerating hard - foot down hard, notice the car seems to over rev or keep the revs high even when I let off the pedal, and sometimes while gentle braking even, continue to rev high and not change up.... then the dreaded 'Restricted Perfomance' bong, leading to lack of power and about 40mph max. Both times a turn it off an on again resolves the problem and I go on my way at a more sedate pace.

Can anyone shed any light on what me the issue with the restricted perfomance issue and over revving or anyone also experienced this behaviour.?

I've not had a chance to pull over and read the codes with the error on the dash - and by the time i turn it off and on again the faukt has gone.

Thanks muchly Ash
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2016 SDV8 AB

Theres a potential danger with this, if turbo's are leaking oil and it collects in the intercooler, when you boot it, the oil is ingested into the engine and the revs will rise out of control. If the turbo's fail catastrophically at this time of overboost / over rev they can then feed the engine with lubricating oil which it runs on and diesel runaway is complete which destroys the engine (it cant be stopped).

I had this happen on a Mondeo automatic and the whole process took less than a minute to wreck the engine completely.
I may be wrong but it may be worthwhile taking a look at the intercooler hoses and see if theres much oil in there. BMW i3 Electric Car
2012 Full Fat RR 4.4 TDV8 (now gone)
2006 VW Touareg 3.0 TDi V6

Thanks AJ - Will do Ash
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2016 SDV8 AB

Hopefully I'm wrong, it's just something to be aware of as a possibility. BMW i3 Electric Car
2012 Full Fat RR 4.4 TDV8 (now gone)
2006 VW Touareg 3.0 TDi V6

Engine runaway will be stopped if the air intake hose from the intercooler to the throttle body is mostly blocked by squeezing with multigrips or is removed or cut open. Having a large screw-driver handy to loosen the clamp at the intercooler would be be the best method as the hose will blow off once loose enough. I stopped a TD5 by squeezing the hose with multigrips.

I've made a device that closes mine's EGR butterfly for a few seconds whenever the ignition is switched-off to stiffle any runaway if it occurs.

You have to be a brave (or desperate) man to stick your hands anywhere near that lump if it's revving out of control beyond the limiters etc. I agree that blocking the inlet would stop the engine but if it does kick off you have very little time to do it before it's too late. BMW i3 Electric Car
2012 Full Fat RR 4.4 TDV8 (now gone)
2006 VW Touareg 3.0 TDi V6