Cummins 5.9 300hp

[fishpcb]

We went out yesterday on a 37' President with twin Cummins 300hp. The starboard engine starting smoking all around the elbo coming out of turbo going into exhaust. This happened when it was ran up to WOT. Temp hit 205 then come down as power was reduced. The elbo smoked like it had oil inside with pinholes.
Could this be the elbo and water holes are stopped up? It's not my boat but I'm looking at one with the same motors.

 

[Ski in NC]

If engines have not been run hard for some time, it is somewhat normal for that area to "cook off" oily deposits and make smoke. Not normal for it to leak anything. And not normal for it to run up to 205F. Sounds like it needs some maintenance.

 

[fishpcb]

The boat has not been run much in the last year. Basically just started ever couple of months and idle at the dock. I think this is the first time it's been out and ran over 30 minutes.

 

[fishpcb]

The temp did come down right away after pulling back power. Also both engines did go up and make 2800 rpm as the book says it should. Other than the smoke at the elbow it did pretty good.

 

[High Wire]

If you have engine exhaust leaking into the ER, thats is a safety issue which should be corrected immediately.

 

[fishpcb]

It came in when the engine was running wot. It's been a year since the boat was ran for more than 15 min. I think it needing running to clean it out

 

[bayview]

Cooling down with reduced load indicates insufficient raw water flow. Now the exhaust hose may be damaged. Plugged system may indeed be the cause but bad pump impeller is the first suspect.

 

[fishpcb]

We will check it out. Then post what we found.
Thanks

 

[fishpcb]

The good and bad about the boat running hot.
The bad is the guy didn't want to spend any money on the boat and made me a offer I couldn't resist. So I bought the boat.
The good news is the only thing wrong with the boat was a bad thermostat and bad turbo gasket. For less than $40 I had it running cool and stopped the exhaust smoke.
Now going to replace all the old hoses and clamps plus hot water heater .