3208T sooty exhaust, starboard side

[capt2kids]

Hi,
I noticed on a trip, that the starboard engine was smoking a little, the brownish color at 2200 rpm. Below that, no smoke, just runs normal.
But right about 2200 or above, i can see it. At 2400 and above its black smoke. not the brownish color.
I replaced the air filter. It was not like this last year. I thought because i had such a load on it, it was the problem. But yesterday just my g/f and I went out of Atlantic city, and coming in, I kicked it in the ass, and it did the same.
It runs ups the way it should, but just smokes like hell. Its not oil smoke. After initial starting there is no slick in the water either. I have only had it for little over a year, so far its been great, except for the oil leak i found.
But they start right up. A great little boat, but its only the starboard side, so i was going to change out the injectors. If it wouldnt come up to rpm, i would say the turbo.
Help!!!!!!
thanks in advance
bob k

[In Memory of Vicroy]

Its unburned fuel caused by too much fuel and not enough air. Start on the easy side, the air. Check that something is not stuck in the air filter opening, like a paper towel...then take the air cleaner off and see if you can spin the turbo with your fingers. Now very carefully check the pressure air side of the turbo for loose clamps from the turbo thru the aftercooler and into the intake. I had a loose clamp on the pressure side of one of my Cummins one time that caused the exact same thing, it was losing pressureize air.

Fool with the injectors last - the odds of most or all of your 8 injectors going bad at once are slim. A stuck open thermostat causing the engine to run too cold wil do the same.

UV

[CaptPatrick]

Now very carefully check the pressure air side of the turbo for loose clamps from the turbo thru the aftercooler and into the intake. I had a loose clamp on the pressure side of one of my Cummins one time that caused the exact same thing, it was losing pressureize air.

I'd almost put money on that being the problem... Even a little loose is no good. Look for the short blue silicone hose, about 2 1/2" diameter.

[Bruce]

Given the 3208 is a wot 2800 rpm Engine, the rpm your reaching without smoking would indicate the turbo is not frozen but more along the lines of a leak as the boost builds.
Usually you wouldn't get past 1500 before black smoking with a frozen turbo.
When you pull the filter off to check blade spin look at the blades and make sure the blades are clean and smooth and not gunked up with debris.

Check back after checking these things if you find nothing.

[capt2kids]

Thanks everybody. I will get back here as soon as I check it out.
I know for a fact already no air cleaner obstruction. I put on a new filter. Also i looked at the turbo for dirt and i spun the turbo, it was fine.
But i will check the hoses for a break or a loose clamp.
Thanks again for the help. I hope nothing major. I'll pay special attention to the hoses. i know one of them goes to the PCV cannister. Last ditch effort, ill swap the cannisters.
bob k

[Bruce]

The turbo outlet should not go anywhere except to the intercooler or intake if you have no cooler. The breather hoses for vapor won't matter.

If you find no hose issues you could have dirty intercooler fins.
A way to check this is without dissasembly is with two 30psi gauges.
One on the inlet side and one on the outlet side and they should read the same pressure.

[capt2kids]

Thanks for all the info. I checked everything i could except for what Bruce told me to check. Please help me, but behind the turbo thats the intercooler? It has one hose in and one hose out?What goes thru those hoses?
the intercooler is sandwiched between the turbo and exhaust elbow?'
Does the intercooler have any mechanical parts? What role does it play?
Sorry i am so stupid when it comes to Cats, i always had detroits.
Bruce what kind of gauges do i use? if i have different pressure, it means its clogged somehow?
Happy Fathers Day all/
bob k

[Bruce]

An intercooler has one hose in and out for air and the same for fluids. In is from the turbo, out goes to the intake. Many intercoolers can be hard plumbed into the cooling system most are hose plumbed.

Depending on the hp rating the cat 3208 intercooler usually sits on top right behind the injection pump across the V shape between the heads.

Its is basically a radiator for air. When you compress air(turbo), the temp increases. The intercooler being cooled in marine mostly by raw water decreases the air temp because engines like cooler incomming air will develop more hp from it. Besides its being driven by exhaust gases which get pretty hot also and transfer that heat thru the turbo housing.

What the guages will show is if there is a pressure differential between inlet and outlet. This would indicate dirty fins thus preventing the proper amount of air going into the engine at higher rpms usually leading to black smoking.

Even with an air filter these fins can clog over time and just like a heat exchanger need to be pulled and cleaned as the water going thru them will leave deposits and lead to less heat transfer decreasing hp.

If the pressure readings are the same, let me know how many hours you have on the engine. We'll have to look somewhere else.

No chance you have something around the prop?

I pm'd my number to you if you get on the boat and have questions.

[Charlie]

No intercooler on 3208T. Sounds like you are loosing boost. When mine will not turn up it is the fuel filters, but not much black smoke.

[capt2kids]

Yes Charlie, ur right, no intercooler. Its only 260 hp. And Bruce told me where it would have been, and it wasnt there.
I'm headed down now to look and take it for a ride. Bruce was gracious enough to give me his phone number, but i wont bother him unless its absolutely necessary.
thanks,
bob k

[Charlie]

Bruce gave some excellent advice. The old rope around the prop trick is one almost no one thinks about.
As Bruce pointed out it could be a number of things.

I just spend two days trying to figure out a high pitch squeal coming from the front of a motor. It would come and go. I tighten the belts and after a hard run it was back. At the dock it would go away after a while. I got a mechanic's stethoscope and listened for bearing noise. Since the squeal was loud I figured it was the water pump bearing. The bearing is only 27 years old. No noise at the bearings. Belts look good, but I changed them anyway. Squeal went away. It sure did sound metal on metal. Go figure. At least that saved me over $500 bucks for a new pump. I figured to get a new one and rebuild the old one for a spare. The bearing is $110 bucks alone.
Hopefully it is something simple.
Good Luck