Smoking 740 Turbo!

Okay fixed the wiper fluid problem~ now I wish that was my only
problem!
This one has been ongoing....
Wife's car is a 1990 740 Turbo Wagon.
About a year ago it started smoking. Badly. Intermittently though.
Replaced head gasket.
Nothing for a while. Then it smokes again.
This time rebuilt the turbo.
Nothing.
Just when we think it's okay....it smokes again.
Our mechanic did so much I can't even remember everything....but it's
been good for about 6 mnths.

Hang on though~ guess what happened today?
Yes~ SMOKE! Blue smoke but only for a minute. But it was BAD!

A while back wife noticed oil in the coolant tank... Related?
Any ideas? Our mechanic moved so can't go back to him. I'm fed up and
at a complete loss. Would LOVE some help! Any input on things to
check....really, ANYTHING are appreciated.
Thanks!

 

Clogged crankcase breather? Did it happen after coasting down a hill?

 

It actually usually starts while idling at a stop....but has been
known to do it while driving.

 

My wife 740 turbo did that as we were getting the air regassed .The mechanic
said why bother the engines shot its fine now and never messes up it was a
quirk of the day .I think a new ogygen sensor helped as well .

 

So this all points back to the clogged crankcase breather?

Sorry, not sure what you meant by getting the air regassed?? Can you
clarify?
Thanks!

As it is, our mechanic who was great got into some kinda trouble
(drugs, money, both, whatever) and skipped town. Now wondering if any
of the work he did was even done and if it was done was it done
right...?

 

I'm pretty sure he's referring to getting the air conditioning recharged
with refrigerant.

 

Aha! That seems obvious now! LOL
Thanks!

 

Sorry I speak in strien down here where the water flows down the sink the
other way I try to think American but frankly its too odd for me .EXAMPLES
FOLLOW .fawcett a tap trunk a suitcase not a boot as on a car .bonnet a hood
..a hood a criminal fender a mudguard .petrol gas . gas liquid petrolium
LPG.fender bumperbar .motor engine .windscreen windshield .rubber boots
gumboots or wellies .AIRCONDITIONING regassed air regassed .Fire up the
engine yes I did that once, we just start the engine .exhaust headers.doing
a head job ask monika and clinton about that one .gear lever gear shift .but
on one thing we agree Volvo means real cars .