Grey Smoke!

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swanny

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Had my MD17c reconditioned in situ three years ago - new cylinders, injectors, piston rings etc €4,000 worth! There was still some grey smoke back then but the engineer in Kappeln, Germany told me perhaps the only way to stop this would be to fit a reconditioned fuel injection pump. Now after three years the grey smoke is worse than ever although it does sometimes appear as though there is a tinge of blue colour at the edges of the smoke. Often there is also a light film of what can only be oil on the water.. She appears to run fine, always starts first time and although I have not used it so much in the past three years it has never failed me. But the smoke! Often other boaters beckon me to urgently look at my engine as they think perhaps I have no cooling - they think it is steam! I don't think so, the cooling is regular if not gushing like modern units. The cooling channels were also cleared during the recon. Any thoughts other than 'Re-Powering' with a nice red Beta???????????
 
Is your engine perhaps being over cooled? Is it getting up to the correct working temperature (82-88degC)? Have you checked your thermostat?

Alternatively, take the boat out for a real blast. Diesel engines are working engines and need to work hard. It may clear the engine out a bit if you give it a good workout at prolonged high revs, especially if you only give it gentle use most of the time. Afterwards, the smoke should be gone.

If not, you may have worn bores or injectors. Does the oil become very dirty (black) very quickly ater an oil change? This is often a sign that the engine is quite worn.
 
Ah! Engine doesn't get worked hard at maybe you are right - and the temp guage is very slow in coming up although when I open the engine box up after a run, it certainly feels hot enough! The gauge appears to read normal I would say. Perhaps I should let a clever person fiddle with the top end to see it can tune up a little. The oil is remarkably clean after this season although like I say, not much use this year. I guess I tend to underuse it because of the smoke which might make it worse???? I certainly never run at full revs. I'll give it a try, she's still in the water. Thanks.
 
Most engines have distinct different temp run req'ts depending on whether they are direct raw water cooled - the it hads to run cooler to stop creation of slat encrustration in channles due to heat ... Heat exchanger engines having fresh water in the channels are set to run a lot hetter via thermostat.

I didn't know anything of this till I re-read my Perkins books ... and then asked around - seems other engines have similar as well.
 
If it is not steam then grey smoke in diesel engines is always unburned fuel. Causes are usually lack of compression or an injector problem. No way should a reconditioned engine be giving out grey smoke.
Recommend a Beta if you decide to re- engine
Martin
 
If you can live with it do so, all diesels smoke even new ones,possible causes are, underworking,give her a full power run for at least 30 mins,dripping injectors,get them serviced,bad fuel, how long has the fuel been in the tank?the clean oil is a clue to the engine underworking,but i would live with it and save your money.
 
It's possible that you have a duff cylinder............. valve,or injector. This could cause the grey smoke and the slow rise in temperature due to not burning the fuel.

Compression test and start from that point.......... first

Dont spend money on fuel pumps until you have checked everything else.

Tom
 
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