ENGINE SMOKING

[sundown]

Any suggestios on what may be making a Penta 17c smoke? The smoke has a blue tinge to it and the exhaust leaves an oil slick in the water. The cylinders pressure test out to 360, 380, and 380 psi. The valve guides were replaced two years ago and still appear to be supple.

At present the engine is apart (again) trying to solve this problem. The rings seem to be fine (none are broke and all are free)

The engine smokes so much on start up that it is embarassing to fire up in a marina unless there are hordes of mosquitos around -then I can claim we are performing a public service.

[never monday]

rings or valve guide seals. on some of the MD series there was a CCV hose to the intake. see if you're dripping oil out of the air cleaner

[Sandero]

Did the smoke go away after the engine reached operating temperature?

I have a 17D and recently rebuilt the top end of the engine (a broken valve spring) but did not do the lower end (rings). My engine DOES smoke on start up when the engine in cold. and it DOES eject a bit of oil slick which I think is unburnt fuel. As the engine warms the smoke disappears and this appears to be related to operating temperature. So in warmer weather the engine warms up sooner and the smoke stops sooner. In summer when the engine is warn or hot (from recent use), there is hardly any smoke on start up. I think the smoke is unburnt fuel. However, when the engine was new I did not have this problem. And that is odd. Aint it?

Since the smoking stops when at the engione reaches operating temperature I am not terribly concerned but it could be embarrassing I suppose. You can see the amoiunt diminish as the engine warms.

Yet another reason not to moor at a marina.

[Chief Engineer]

What possesed you to tear down the engine?

There was an article in one of our local boating mags (Nor-Easter) about a cruising couple that came to Baltimore. Their engine was smoking. They went through he-double hockeysticks with tear downs, outrageous attitudes, they even machined the head...all to solve a smoking problem....the owner of the yard wanted them to pay-up and leave with out problem being solved.......ended up that a yard on the upper eastern shore's mechanic (I know him...he's a good wrench) set the injector timing to factory specs and the smoking disappeared.

Look for the simple things first

[sundown]

Never on monday: I will check the air intake filter tomorow - thanks for the suggestion.

defjef: The smoke does disappate considerable when the engine heats up - but it still is problem. I had the injectors rebuilt so they should be ok BUT it could be the metering from the fuel pump - I will run that one past the mechanic and get him to check it.

Chief Engineer: Ripping the engine down (again)was the mechanic's idea: I had managed to get water in the cylinders a couple of years ago and we pulled the engine down at that time to make sure I had done no damage. (it is a long convuluted story that starts from me changing the type of cooling thermostat. One would think that at 65 I would have learned to leave well enough alone ). The long and short is that the engine did not smoke before I started 'fixing it'. The suggestion of fuel metering is one that had not crossed my radar - it will be pursued.

Thank you to everybody for thier suggestions. When I finally get the problem solved I will post what the fix was

[Alan Wheeler]

How many hrs has it done??
Does it get a good work out every now and then??
Do you get into gear and get it working, or do you sit at the dock and let it warm up before getting into gear??

[Chief Engineer]

What part of the "Blue Planet" are you currently on?

[Elie]

I had an MD17 HD, and I think than is not a good idea to dismantle it before trying seriously to establish a solid diagnostic of the cause this smoking. In my opinion this smoking is fuel or injection related: probably an dirty injector or in worst case, the injection pump itself out of specs. I also had this type of problem once when I took fuel at a fishing fleet docks somewhere in North Carolina. Keep in mind that these solid Volvo engines, run at relatively low compression, are a bit smoky to start with, and any miss adjustment in the injection process, creates significant smoking problems. But they are strong and won't be stopped easily: I spend the last few days of the sailing season one running it with a blown head gasket on one head, that put one cylinder out of commission essentially, but the engine run to let me finish my season. Sending the injectors, and the injection pump to an injection shop would be a good start, and anyway it is alway good to have them checked, cleaned, and put back to specs. A single injector leaking a bit would perfectly create such smoking problem.

[Chief Engineer]

Imeant to post on the thread about re- using
eninge oil into the diesel tanks
Sorry.

Originally Posted by Chief Engineer

What part of the "Blue Planet" are you currently on?

[Sandero]

Smoke is evidence of poorly combusted fuel. It would seem that if the smoke problem abating as the engine is warming up it means that the "environment" in the cylinders is changing. A warm engine has tighter clearances doesn't it because the metal expands a bit when hot. This means that the fuel is delivered hotter, the compression may be slightly improved and so forth. If the healthy engine can produce no smoke from a cold start it would appear to be a ring or cylinder problem or similar related to the failure of the cylinder to combust the fuel. It could also mean that there is too much fuel which means not all of it can combust. I don't know how this is effected by operating temp. Perhaps this is related to the injector specs.

Just a guesss from someone who knows nothing about diesels.

[Sailorguy]

My diesel started smoking like a mosquito fogger; found that the breather hose (from the valve cover to the air intake) had collapsed. Replaced hose and smoke problem went away.

Steve T

[Alan Wheeler]

Smoke is evidence of poorly combusted fuel

Depends on what colour the smoke is. The light blue hazy smoke that occurs at initial start up is usually librication oil, or the heavier fuel oil left behind in exhaust and cyclinders after shutdown, when the lighter compnents of fuel evaporate away. This sign is not usually of concern.
Heavy white'ish grey'ish smoke in great quanities is a sure sign you have very bad compression. Black smoke while under load is a sure sign of unburn't fuel due to air starvation of some kind.