Outer Limits 4x4 Board

hi!! my dad just had his motor fully rebuilt new head the works(2h motor) every time he starts it up when it's cold it blows bluey white smoke, just wondering if anybody would know what would be causing this. he took it back to the mechanic and they have checked the glow plugs and a few small things, no problems that they can see, do the rings just need to bed in better or is that colour smoke mean problems, it's only done 1000klm's since the rebuild. thanks

1000k's is more than enough for the rings to bed in, and i dont think it shouyld have blown any smoke even if the rings werent bedded in.


I would be taking it back and demanding they they resolve the problem.

Glow plugs might explain the white smoke but not any blue smoke. Thats oil and definantly should not be there in a freshly rebuilt engine. This is why you get a warranty.

i know its fairly new but white smoke first up in morning could mean cracked head leaking water into the bore. has the head been crack repaired?

Has the motor been reconditioned or just rebuilt? rebuild=tear down and reassemble.

What parts have been replaced?

Blue smoke indicates oil burning. White smoke indicates excess unburnt fuel. Black/grey smoke indicates overfuelling.

Blue smoke can be caused by cracked or worn rings, crook valve stem seals or excess blowby being burnt by the motor. Oil sometimes builds up in the intake manifold from the crankcase breather.

White smoke is usually a sign of either crook glow plugs, or poor compression, or extremely cold climate. It basically indicates that the fuel isnt burning properly.

Did you run the engine in at all?
Did he build it himself? if he didn't just go straight back to the place that built it

White smoke is unburnt diesel, or blocked inlet filter.....there is something real wrong here, maybe valve or pump timing is out....maybe injecters are stuffed, but if it didnt do this b4 then it shouldnt now...
White is also coolant...does it start on all 6 pistons or run on 5 for 30 seconds or so....
Andrew

this is a fully rebuilt motor $7000 worth the head is brand new same as pistons rings every possibly thing as far as i can see on the invoice, he is a very good mechanic my boss has been using him for years on his comp trucks and never had a problem. it's been back and he say's that he can't find anything wrong with it and the smoke is from a build up of oil in the valleys? thanks for your input and might get it back to him again to check a few things you guys have mentioned thanks again

I'd be asking the mechanic to pull the head down and check everything