My Engine blows Blue Smoke – Black Smoke – White Smoke

HomeBlogMy Engine blows Blue Smoke – Black Smoke – White Smoke
Posted on 2 December 2016

Free Smoke Test

We do get asked a lot about what does this colour smoke means.

So we put together our own smoke analyser

Why does my diesel engine blow black smoke?

Black Smoke: It indicates poor and incomplete combustion of the diesel fuel.

  • Block air filter or intake system
  • Problem with fuel injector pump or injectors
  • Engine timing out
  • Low cylinder compression (i.e. cylinders, piston rings, ring grooves)
  • Restricted induction system
  • Excessive carbon build up in combustion and exhaust spaces
  • Incorrect valve clearance

Why does my diesel engine blow blue smoke?

Blue Smoke: is an indication of oil being burnt.

  • Low cylinder compression (i.e. cylinders, piston rings, ring grooves)
  • Worn oil rings – sticky oil rings when cold.
  • Worn valve guides or seals
  • Cylinder head pooling oil ,valve oil drains blocked /sludge and poor PVC valve, similar to valve stem seal problem – called the “sludging” issue. Common issue on later model engines past 2003
  • Cylinder glazed
  • Incorrect grade of oil (e.g. oil too thin, and migrating past the rings)
  • Fuel dilution in the oil (oil thinned out with diesel)
  • High engine oil level

Why does my diesel engine blow white smoke?

White Smoke: occurs when raw diesel comes through the exhaust completely intact and unburned

  • Faulty glow plugs
  • Low engine cranking speed
  • Problem with fuel injector pump or injectors
  • Incorrect injection timing (could be a worn timing gear or damaged crankshaft keyway).
  • Fuel air leak
  • Low cylinder compression (i.e. cylinders, piston rings, ring grooves)
  • Incorrect valve clearance

 

We can also help to provide you with oil analyses too.