Originally Posted by callistov42
Just repowered my boat with a new Yanmar
4JH-5E. The engine is not broken in yet. It only has 3 hours on it now. It is smoking heavily. White smoke, not blue smoke. My mechanic says that it is fuel, not oil
. He says that the engine needs to be run and the rings need to settle in so the compression
will go up and burn the fuel better. I am going to take it out for four or five hours this weekend to run the engine under load. Does the smoking seem right?
I am also going through the brand new 4JH-5E break-in (I have two hours on the motor
, started Monday late afternoon), and am not having any problems with the motor
- it's burning well with a clean exhaust
. I'm running the motor at 2600 rpm
(recommendation from Yanmar was 4-500 RPM
under wide open throttle, which is supposed to be 3000 RPM). Yanmar wants this to be done for 10 hours before doing much else with the motor. Most importantly, do not run the engine at idle or low load.
Has your motor run under load during your 3 hours? If not, as per prior post, run the motor under load to seat the moving parts
- compression should then go up and the fuel should burn better.
Below is my quicky cheat sheet for diesel exhaust
color (stolen from here http://www.uniteddiesel.co.uk/diesel-engine-smoke.php):
I sure hope your motor comes up nicely; it's been a rather expensive three month job on my end to get this far and I'm super happy that all is going well.
This is due to a air to fuel ratio imbalance, either the fuel system is delivering too much fuel into the engine or there is not enough clean air (oxygen ) a few things to look for :
- Faulty injectors (injectors need attention at about 100.000 to 120 000 miles)
- Faulty injector pump
- Dirty air cleaner
- Turbocharger or intercooler faulty
- Problems within cylinder head, valves clogged up due to faulty EGR (exhaust gas recycling unit)
Normally means that the fuel injected into the cylinder is not burning correctly. The smoke will burn your eyes.
- Engine/pump timing out
- Fuel starvation to the pump causing the pumps timing not to operate correctly
- Low engine compression
- Water/petrol in the fuel
The engine is burning engine oil
- Worn cylinders or piston rings
- Faulty valves or valve stem seals
- Engine over full with engine oil
- Faulty injector pump/lift pump allowing engine oil to be mixed with the diesel