Hi, new to the forums. I have a problem with my engine, it’s a 1.5 BMC. It started to smoke really bad and was very low on power with a misfire blowing clouds of white and bluish smoke like a 50 a day smoker but maybe worse, occasionally a hoop or two as it makes a popping noise from the exhaust. It kind of dies down when moving and under load but comes back as soon as it’s put in neutral then the misfires start again and clouds of smoke from the exhaust, smells a bit like paraffin. I have to be honest, the engine wasn’t running very well for the 3 years I’ve had the boat and it has always kind of smoked, black smoke mainly so I believe to much fuel but it didn’t really bother me as it seemed to chug along fine. I’d like to add that I knowingly added the wrong oil, I think it was 5/30 fully synthetic about 6 months ago, only because the oil level was low and it’s all I could get (I think 2 litres) I haven’t bothered servicing it since.
I checked the engine and the head gasket was leaking water and oil so presumed it was the head gasket. I’ve stripped the head off, checked for cracks (no need for skimming), checked the cylinders (seem fine to me no scratches) visually inspected the pistons and all seemed ok, replaced the valve stem oil seals, grinded and polished the valves because there was a lot of pitting on the sealing faces, set the tappets and replaced the head gasket. Put it all back together and it’s still the same. I have noticed a tapping noise that gets louder as you rev the engine that makes me think there may be an oil supply issue (possible blocked oil filter as I haven’t changed it yet because I could not get the engine to operating temperature to drain the oil using a pump) the tapping goes away if I apply full throttle and rev the engine then reappears occasionally but I’m still left with the misfire and the clouds of smoke polluting the environment.
I was hoping someone on here could point me in the right direction as I’ve spent a few days trying to figure out what the fault could be. Could I be right in assuming maybe the timing chain tensioner or chain are to blame and messing up the injector timing, possibly faulty injectors or am I just hoping it’s an easy fix and the engine needs a full rebuild ?
If anyone else has experienced the same problem or symptoms and managed to sort it I’d be happy to hear from you