(26 Jul 2020, 10:33 pm)streetdeckfan wrote I wonder what part of the engine makes them so unreliable.
Clearly it's not a major failure otherwise they'd be off the road for longer, so it must be something small, but that keeps recurring
Probably due to the smaller engine, the B9s engine was very under stressed for its application, 260ps from a massive 9.6 litre engine, the same basic engine making 380ps in the B9R coaches just shows how under-stressed it was. A little 5 litre, same size you get in streetlites afterall, doing similar work to a 9 litre+ just gives more potential of going wrong, even if it’s fundamentally a good design, which I’m sure it is being a Volvo.