2001 Volvo C70 juddering in neutral

all lights can be read with a scanner.the revs are limited by the ecu to avoid engine damage,this is normal when lamp is on.
the vibration could be the duel mass flywheel when they start to break up a vibration occurs after that complete loss of drive as the engine is no longer connected to the gearbox.just a thought id get it to a garage with experiance of these problems

From experience...as mine is in the garage for much the same thing. I began to experience the same problem. The other night the rev needle started hunting (moving up and down). after it warmed up the problem went away so I put this down to the extreme wet weather we have been having. However this morning it did the same again, I drove 5 miles down the road and the engine warning light came on. It might as well have a pound sign instead of a picture of an engine. I have driven down to deadmans cross garage as they are the nearest and they had a diagnostic computer which has pin pointed the problem to the intercooler. There is probably a hole in it poss caused by underside damage in the past. I havnt had the car long so it must have been brewing a while. They have to take the bumper off, so so far the cost is £139.00 which is the labour and diags. So far cheaper than volvo dealer however its still more than I wanted to pay. The price for a new intercooler is approx 200 plus, and I have a feeling it cannot just be plugged and repaired as it is a high pressure system.