OK so I thought I had the car diagnosed correctly and it very much seemed like the DMF was bad. I have since dismantled much of the front of the car to repair that along with other things. But now that I have the original DMF off, it does not seem to be in such a bad shape after all... The symptoms the car originally had (with 100k miles on the original clutch and DMF): Very often there would be clatter when starting the car cold. Not upon every startup though. Clatter stops when clutch is depressed and comes back when clutch is lifted again. A pronounced "clank" when lifting off from a standstill. Right when the clutch engages, there's the clank. And also when shifting gears, once the clutch gets connected again, clank. When the power train warms up, the clatter will lessen, can even go away. Sometimes the clatter is there when idling with warm everything, sometimes not. Clutch becomes much less noisy after a period of driving, often it begins acting quite normally once warm. There are no other strange noises from either the engine or the gearbox. And the clatter is definitely connected to the clutch action in some way, as with a depressed clutch the clatter is gone. When I first test drove the car, there was no clatter at idle. The clutch felt a little clunky, but not noisy. Then after several startups and about 30 miles total driven, I started the car up again one more time. Very prominent clatter from the engine bay. So in short, it all sounded and felt exactly like a bad DMF. But now I am puzzled. Could it be that the old DMF is faulty even if it looks and feels exactly like the replacement one upon inspection? And if not, what else could be the problem causing this clatter? Could it somehow be a gearbox problem? FWIW the gearbox seemed to work faultlessly; no worn synchros, no noisy bearings and/or gears, it worked extremely smoothly in every way. --------------------------------------------------- Thing is. I have a replacement DMF, a used one that was checked by a Renault tech who said it was fine. In terms of play, it has six and a half teeth of movement. Prior user also said no problems with the DMF. But. With comparing the replacement DMF with the original now that both are off, they seem to be in pretty much identical condition (!). Exactly the same amount of play in all directions. So...Do I have some other problem causing the clatter or could the old DMF still be the culprit even if it doesn't seem that bad when testing it by hand. Clutch itself didn't show any signs of damage, only normal wear. Sorry for the wall of text and thanks for all your help!
Actually, if I do remember the symptoms correctly this would in fact indicate a problem with the gearbox and not the DMF, since the rattle goes away when the clutch is depressed and comes back when it's released (!). If there is a bearing failure on the gearbox which would cause this, what would my reasonable options be? How much does a good condition used gearbox go for, and what are some ballpark figures for a partial rebuild?
Someone elsewhere mentioned that the culprit might even be the crankshaft thrust bearings. But since the sound is a rattling kind when idling, and not only the single "clack" when clutch is released I don't know if that could be. Someone wiser?
