Black smoke when turbo kicks in

[labrador]

Have cummins 330bs with 1350 hours on them. Just got the boat in Jan however have put over 150 hours since then. Always had a little grey smoke on start up however was gone in 2 to 3 min and never saw any black smoke when I put the throttles down and the turbos kicked in. The last 2 weekends I see a noticeable delay for the turbos kicking in and black smoke from the port engine which disapears in 10 second or less. The bottom is due for the diver, 3 weeks since, and the oil was changed about 15 to 20 hrs ago. Any ideas on what I should be looking at?
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[labrador]

Not even a guess?

 

[bigbill]

do you have air filters? maybe they need to be cleaned. i'm sure the bottom cleaning will help. have you added a significant amount of weight since you purchased her? all of those little things add up

 

[saltshaker]

Only one engine is smoking? I would start withe basics like fuel filters and bottom cleaning. If that doesn't fix it check for fuel or air restriction. Do you have boost gauges?

 

[Will]

"Turbos Kick In" is often a misleading term. In most all cases, turbos function and run all the time increasing speed as the engine increases speed and the exhaust flow increases. There is a point at which you begin hearing them whine but that is just a sound. It doesn't mean that they are suddenly beginning to provide turbo assist.

As previously mentioned, dirty air intakes are a probable cause. What happens if you bring your throttles up very slowly? Do you still have the smoke?

Will

 

[Avenger]

We just had a case with a Volvo that had the exact same problem. The exhaust housing of the turbo was beginning to rust out and the clearance between the housing and the turbine had become excessive, allowing exhaust to bypass the turbine.

 

[labrador]

Thanks I have walker air seps so guess maybe look at cleaning them? No boost gauges Jack. Will check the racors also.

 

[doc g]

Typically it means lack of boost,(not enough air/too much fuel) or overloading. Had it happen when I blew a boost hose on mine.......Pat

 

[REBrueckner]

You won't believe this but a restricted (dirty) fuel filter can cause black smoke....I had it happen once on a Detroit....see Angela's RPM SPIKE, Black Smoke....on this page currently....that turned out to be her problem also. As noted by Saltshaker, dirty props is also a possible..

The more rapidly you pin the throttles to the max the more likely you'll get brief black smoke...so a gradual increase in RPM while your engines come up to temperature is wise.

 

[yachtsmanbill]

Still a classic!! ws

http://www.youtube.com/watch?v=_gXjN60SLwg

http://www.youtube.com/watch?v=ifkfGV7L0CI&feature=related

 

[krush]

We just had a case with a Volvo that had the exact same problem. The exhaust housing of the turbo was beginning to rust out and the clearance between the housing and the turbine had become excessive, allowing exhaust to bypass the turbine.

And this probably showed up on the boost gauge (if it had one). Boost gauges should be installed on all turbo'd engines for reference/diagnostics.

 

[Avenger]

It did. Boost was low and the engine smoked and lagged until the RPM got to the point where there was enough exhaust volume that it couldn't all bypass the turbine. It's actually a not uncommon problem with marine turbos.

Of course, I too would still check the basics first.

 

[Iggy]

My limited experience tells me clogged fuel filter. Second air filter.