Help with blue smoke issue

[Archie0979]

I have recently bought a Avensis 2.2 d4d 2007. I have had it in the garage to get some minor issues repaired. It had some slight amount of oil dripping from the intercooler intake hose which the mechanic has already said is not an excessive amount and not to worry about my turbo as it isn't blown. He has cleaned and replaced the hose and it is much better but still leaking slightly, he is waiting on a new hose and o ring seals and will replace them next week. I also had an issue with a hard cold start where you could physically hear the diesel running back from the fuel filter housing and causing air to get in to the system. If you primed in manually until hard it starts first turn of the key with no problem. The housing has been replaced and it starts much better but still not perfect. The water pump was leaking and has been replaced and also my belt was making a noise and has been replaced. The mechanic had said the oil had not been replaced in a long, long time so the filter and oil was done. The only issue he can't figure out without further investigation is that once the car has been sitting idling for long periods of time the car starts to give off blue smoke. The longer it sits the worse it gets. Under normal conditions you don't get any smoke AT ALL when starting or normal driving. He said it could be a few thing's but because of the age of the car he said it might not be worth it as he might not find the fault at the first attempt and the labour will add up. To add the breather hose was smoking heavily at idle in to the intake system but again it clears after running normally. Nothing is pointing towards the head gasket and he thinks it is probably the valve stem seals but it could also be the piston rings, turbo seals, injector seals or a sticking/failing injector. Has anyone else had a similar experience with this issue? I might add that I have no EML light and the car has no loss of power and pulls like a train although despite being a diesel I still think it is slightly lounder than I would expect.

 

Just wanted to add that I also have diesel redex system cleaner in the fuel. This is a very dark blue colour and I have read that the burning kerosene in the redex can cause blue smoke, does this sound right?