Right.

Diesel engines produce lots of torque. That's why most people like the feel of them - that 'wall' of torque that you have from lowdown right through the rev range.

The DMF is there to act as a shock absorber for that torque - especially in low gears - otherwise that torque would be sent straight to the gearbox.

Remove the DMF, and you WILL end up tearing the gearbox apart. If you're the type of driver who has managed to go through 3 DMFs so far (I've been driving diesels almost exclusively, doing 30k+ a year for the last 15 years, and not managed to wreck one yet), then I'd expect the gearbox life expectancy to be a couple of years at most. Possibly just a few months, especially with the remap.

Rebuilding a gearbox is a lot more expensive than replacing a DMF.

If you've re-mapped a Ford/PSA 1.6 16v diesel to 133 BHP you won't have to worry about the DMF for too long, as the engine will probably eat itself!!

The DMF doesn't reduce torque to the gear box, rather it smooths out the torque peaks as each cylinder fires. Removing it can lead to an increase in noise, vibration nd harshness (NVH). Many people that changed to a conventional solid flywheel found that the crank shaft snapped soon after! However, by the sound of it you are talking about a Valeo Kit 4P or equivalent. This is more than just a solid replacement - the clutch plate has singificant rotational flex built into it to take up the former role of the DMF - it is however less than the DMF, so you may find an increase in NVH. Best to treat the DMF with kid gloves, and it should keep going - don't allow the clutch to heat up, so no holding it on hills, and don't let it slip too much as you take up the drive. Don't sit with your foot on the clutch either, as modern release bearings are built down to a (cheap!) price. Note also that changing the clutch on one of these is a PITA as the DMF / Cat has to come out to get access to one of the bell housing bolts, and that often means draining the cooling system and removing the rad.....

Post injection?, a new one on me, what on earth is that?

Not unusual for this engine to eat turbos, but it's for other reasons and this site and the whole motoring world on the internet is overflowing with threads on this engine and its appetite for turbos.

Thanks for that, never realised that regens could cause such damage, is the model known for this particular reason for turbo destruction or is yours unusual?

Edited by gordonbennet on 07/05/2017 at 00:24

Thanks, another black mark for this engine in my book.

Know someone who has an Audi A6 3.0 TDi. Ended up getting a new engine after the old one got 2 melted pistons and stuck open injectors form regen. I know, other engine, other manufacturer, other regen sistem. The ideea is that a blocked DPF is unhealthy for an engine and the regen is what kills your engine.

Thank you for the time!

The other bit of a regen that starts killing your engine is injected diesel falling past the piston rings when an engine has a bit of wear - diluting engine oil with diesel (not a great lubricant). If this becomes really bad and the engine oil level substantially raises with diesel all sorts of problems ensue including potential engine runnaway when engine starts running on it's own sump oil - commonly know as bang!

This was a serious problem on some early DPF installations but fortunately later designs have exhaust manifold close coupled DPF's that are much more likely to achieve passive regen (without injecting diesel!) and where if active regen is required this is much more efficient/quicker.

Edited by Big John on 07/05/2017 at 22:41