Having been in the auto industry for years, many of them as a used vehicle manager, your solution may be simpler than you think.

Humour me by running some combustion chamber cleaner (CCC) through the engine. There are many on the market just follow the directions. Basically you spray the stuff in the air intake downstream from the air cleaner with the motor running and after just about all the can is empty stall the motor with the last of it. Let the motor sit overnight for best results. The following morning smoke your entire neighborhood out by starting the car and revving the motor. You will be amazed at the size of the hole that you can put in the ozone with the stuff that will come out of your tail pipe.

It may sound like snake oil but often it does work. For example my girlfriend’s, now wife, old Festiva (they had a Mazda engine) had compression ranging from 90 to 110 and was using over a litre of oil every 1000kms. I ran some CCC though it started it the next morning warmed it up and did a motor flushed the motor after that. After she ran the car for a week, I retook the compression and it was 145 to 150 straight across. Oil consumption went down to a litre every 3000kms and stayed that way until we sold it 30,000kms later.

The car we replaced it with is a Volvo 740 incidentally.

I have never run CCC though a Volvo but have though numerous imports and domestics and over half the time it does work. Be warned on the odd occasion it has actually lowered the compression. When it does work, what is causing the compression problem is the rings sticking in the piston because of carbon and crud, the CCC clears it out and allows the ring to seal properly. When it doesn’t work the carbon and crud is actually helping what little seal the rings have and removing the crud causes the compression to go down.

It may sound to good to be true but give it a shot. What do have to loose except for the $10 you spent on the chemicals and of course the damage you did to the ozone with the smoke? :-)