Bill wrote:
In message , NY writes
"Bill" wrote in message
tairs...
Where I suspected a resonant frequency of the DMF flywheel masses and
springs, the effect was - for example - when waiting to turn right
across traffic, a gap appears and you let the clutch in sharply,
there is a bang and the engine stops dead. I wonder if there is some
damping on the springs which can fail.

Is that on a Skoda? I wonder if you've fallen foul of the quirk of some
Volkswagen engines (I presume Skoda and Seat use VW engines) - I think
it was the Mark 5 Golf which used the PD (Pumpe Duse) diesel engine
rather than a more modern HDi-type engine. That model of Golf is the
only diesel that I have ever stalled on test drives - sometimes
repeatedly - when setting off. Even when I drive a petrol car (being
used to driving diesels) I don't stall. But that VW seems to have an
ECU which senses that you haven't applied enough power and instead of
chugging, which is warning to apply more power, and eventually picking
up speed, ie normal diesel behaviour, it reacts by cutting the fuel
altogether, making absolutely certain that you will stall. It is also
the only diesel car I've driven that doesn't like being driven in dense
stop-start traffic by lifting the clutch with no accelerator,
controlling the speed by a quick half-blip of clutch (maybe not even
full engagement) and then press the clutch again to coast to a halt a
few yards further on. You have to drive it more like a petrol, with
fast idle and more clutch slippage to avoid going too fast for that
engine speed - not a problem when setting off from rest to accelerate
away, but a problem if you want to move a short distance in a queue of traffic.

It is on a Skoda, and, yes, I think the 1.9tdi is a PD engine (although
I could be wrong). However, I haven't noticed those effects. Maybe your
test drive vehicle had the start of the effect I'm describing.

No, its the engine management just killing the engine if the revs drop too
low. I suspect very low revs can induce damaging resonances in dual mass
flywheels. Ive experienced it in many modern diesels.

Tim

--
Please don't feed the trolls