I bought a 1985 240 last year, low mileage (170000 km) in very good condition, M46 with overdrive.
Apart from the usual maintenance items on a Volvo of this age, it has been trouble free and runs beautifully, especially on the highway. Last week when I started it up to go to work one morning there was a light knocking in the engine in addition to the normal piston slap. The noise gradually disappeared as the engine warmed up as long as the engine was kept under 2500 rpm. Above that the noise was there, though not as bad as when cold. After sweating all morning wondering what to do, I went out at lunchtime to try it again. The noise was gone! Revved it hard, no noise!
This is my first B230E engine, our others are B23s and I am aware of the piston slap, mine disappears within a few minutes. But this noise was heavier and confined to one cylinder. The only thing out of the ordinary was the car was moved from my driveway to the street and back again each night three days in a row. The next morning the knock was there. Oil and filter recently changed 10W30. Has not occurred again in last two weeks. Has anyone else experienced this on a B230?
Thanks in advance for any advice or input.