I have a knock . . . . .

[vhv5hss]

Mmmmm. This could be bad. Anybody heard a big end bearing knock in a 03' Rs6?? Or, of a big end letting go??

May not be quite there yet to finger lower crank issues but have certainly eliminated top end valve train noises as possibilities . . . . . . .

Will keep all posted as investigations unfold . . . . . .

[V8weight]

I've seen the crank pulley come loose on dozens of Audi's causing what sounds like a lower end knock. That's why you always replace the 8 crank pulley bolts during the timing belt service. Something to check before you condemn the rotating assembly.

[kismetcapitan]

fingers crossed that it isn't a bearing. I've spun bearings on my Nissan, and it sucks. Does ATI make harmonic dampers (crank pulleys) for the RS6? Can't hurt in terms of stabilizing potential crankshaft flex, although V-8s tend not to be as prone to flexing.

Do you have a stethoscope? I find them to be invaluable to listening to the insides of a block and pinpoint suspicious noises.

[hahnmgh63]

Never heard of a RS6 crank going. And for that matter anyone here of a 4.2 V8 crank going?

[ttboost]

I can't imagine ANY of these Cosworth motors popping at the power level most of us are at...unless you run it out of oil or something...

[vhv5hss]

Well, in that case it seems that there is indeed a first for everything.

Bearing has turned in #3 big end and opened enough clearance to give us the knock that we first heard and thought as lifter noise. Is interesting as no colour on crank and certainly hasnt seized, in fact, there is no sign of galling and no sign of heat at all.

At this stage have simply dropped oil pan and removed caps. Kinda fascinating in that we can see no sign of wear on any other bearings, no sign of oil starvation, no incidences of low oil warning light, good clean oil (FUCHS SuperSyn) and only 190KM on car. Engine has REVO, otherwise stock, resealed OEM SMIC and pulls like a train.

I guess we will drop engine, open up and see what direction we head. Will keep forum posted.

[kismetcapitan]

were the rod bolts a bit loose? Hopefully the crank journal isn't scored and it'll be a quick fix to size and fit new shells.

I wonder if ARP does rod bolts for this engine; whenever I've had to take apart a Skyline engine (the only car I've really worked on), I replaced the rod, head, and crank cradle bolts with ARP units.