I've recently noticed that when I accelerate in 4th from around 1800 rpm, there is a distinct jolt through the drivetrain or from the engine at between 2000 and 2500 rpm. It's unusual and doesn't happen in any other gear. Any ideas? (apart from changing down to 3rd!)

It maybe the flywheel?

Sent from my iPhone using Tapatalk whilst in a taxi rank

Or an engine/gearbox mount perhaps when the turbo comes in.

My money is on the DMF.

Depending on how hard/fast you accelerate, 1,800rpm is quite low for 4th, especially with the PD's abrubt delivery of lots of torque.

The Dual Mass Flywheel is a weak point and the PD170 eats them faster than most, especially with a regular low RPM / high gear driving style.

My money is on the DMF.

Depending on how hard/fast you accelerate, 1,800rpm is quite low for 4th, especially with the PD's abrubt delivery of lots of torque.

The Dual Mass Flywheel is a weak point and the PD170 eats them faster than most, especially with a regular low RPM / high gear driving style.

Could it be the same if it's on the petrol as that's what I've got?

yip it can mate, i get the same, i also get a thump when i drop from 6th to 5th around 60mph and then put my foot on the gas it as if the gearbox moves totally weird.

yip it can mate, i get the same, i also get a thump when i drop from 6th to 5th around 60mph and then put my foot on the gas it as if the gearbox moves totally weird.

That's exactly what it's like. Oddly, couldn't replicate it today with a mechanic friend in the car - typical. Guess I'll just have to not accelerate from lowish revs in 4th!