[Slimlavud]

Hi all
I have been trying to stop smoking for years - it goes in fits and starts but never for long enough...
I bought a 740 Volvo 2.4TD wagon (estate) a couple of months ago, very cheap and with what looked like a new engine fitted - very clean and not just been steam-cleaned on top. It was very rough and smoky on start-up. starting on two or three cylinders and then chiming in on all after 10 seconds or so. I suspected glow plugs and/or low compression. I checked the valve clearances - all OK. Head bolts are all tight. I changed some glow plugs but the existing ones also all tested good. Found injection pump only held on by one bolt on the flange plus the bracket bolt at the front was tight - I fitted proper bolts all round and tried moving the pump back and forth a bit to check timing roughly - have now got a dial test kit and will check it properly soon. The smoking (grey/blue smoke) continued when warm, a big cloud after idling a bit, on every acceleration with and without turbo. It was not using much oil and was getting around 28-35 mpg. No oil in the water/water in the oil etc. Changed oil for fully synthetic, still smoking the same. About 600 miles have gone by and I noticed number 1 injector dribbling from the joint in the injector body, could be run-off pipe leaking but these are new also, and injectors look new-ish too. Then suddenly, yesterday, it stopped smoking! All I can get now is some black smoke on suddenly accelerating with no load, a bit of smoke when I use the turbo - no more than normal I think. It still starts up on 3 1/2 cylinders and runs rough for first minute, then fine but not much power when cold - I am baffled - any ideas or shall i just thanks Volvo god (Thor?) for fixing it while I slept? I guess it could be a intermittent blowing head gasket or crack in the head between two cylinders closing up sometimes? Shall I just stop worrying?