Poor starting and blue smoke - help and advice
I have an 850Tdi CD Auto P reg (Audi engine)
It smokes terribly when outside is cold, despite new glow plugs. Upwards of 5 degrees it is fine, but still has whisps of light coloured smoke.
The strangest symptom is happens when you are going around 75mpg when torque converted lock up is in operation. If you ease off the throttle, then place it down again when the car is on the 'overrun', the motorway absolutely fills with thick blue smoke and the car clear 'chokes' and then fires back into line.
At 50 or 60, it doesn't do it because the car is in effective free-wheel.
Also, it is worse if you have travelled for a while at a constant speed, and once it has smoked, the second time is not so bad.
My thinking is that somehow, oil is being sucked from the intercooler on the overrun, thus choking the combustion. Once clear, it doesn't happen again. The oil, is suspect, is coming from worn Turbo seals. Does this sound reasonable? Not much oil consumed between 5k services, however.
It has approx 270k miles and is due a cambelt change. I am not sure whether the terrible starting is the same thing, or something else as well such as timing
All thoughts welcome!
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