Still need more info.
Are you using only Diesel Fuel?
Was the Car Smoking like that when you bought it?
What do you consider good compression?
What is the temp range in the area the Car operates?


When my Volvo Diesel was putting out hazy gray Smoke; a little a idle and more when the Pedal was stepped on I took a chance that it was stuck Piston Rings and dumped Marvel Mystery Oil into the Cylinder; and it worked. Details of how to are in the DIY section.

In my Case my Car had sat not running for one year due to a leaking Seal on the Fuel Injection Pump. When I got it running it took me 6 months to realize I was driving with an Engine Thermostat that was opening too soak. Both, resulted in stuck Piston Rings.

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84 300D, 82 Volvo 244Gl Diesel