A6 3.0 TDI - sudden smoke & oil loss –
09-05-2019,09:57 PM
A6 3.0 TDI - sudden smoke & oil loss
Driving along then suddenly clouds of grey/white/blue smoke. Crawled a few miles home, smoke much less off load. Within ten miles, low oil warning.
Car has had history of periodic blue smoke 'bombs' (usually only after unusual attitudes eg multi-storeys etc), so a few months ago I vented the CCV
to atmosphere (via a filter) and the blue smoke 'bombs' completely stopped. Was planning a catch can, but was proving difficult. Now this.
Nothing on VCDS.
No lights on dash.
No rough running.
Idles normally with no smoke.
No smoke on start up or when cold.
No change in power.
Starts and drives normally.
Suspected turbo. No damage to compressor. Clean, with a little fresh oil at intake, but normal 2-3mm radial end float and not touching casing.
Axially, normal play guessing about 0.1-0.2mm. Spins freely. Spindle not broken.
Turbine, no damage. Same axial play, but radial end float barely detectable. Matt black apearance. No visible oil.
Actuator freely operates throughout range.
Charge air from turbo, found a little fresh golden oil (just been seviced) . Enough to dribble one end to the other, but pipe clean other than that.
I'm not convinced it's turbo.
CCV/PCV? Tried a surgical glove at idle, barely half inflates. However I havent (yet) tried that at normal RPMs. I can see a little oil collected at the
bottom of the 'V', right near the CCV, which could be suggestive of it being blocked/high crankcase pressure.
I sucked on this CCV pipe from the air inlet end and it was definately blocked solid. YET, when the engine is running smoke oil is seen.
Is my suck too little and proves nothing, or does this suggest high crankcase pressure to open the valve?
Wonderful car, hard to find now with rare high spec and still with sensible miles, but I'm tempted to throw it in the river!
Any ideas please?
A6, C6, ‘55, BMK, S-line, 4F5, 7GN, Sunroof, Bose, Xenons, LEDs, Valcona, Pearlescent