Uneven turbo pressure at cruise 370hp BTA

[Tom M]

Guys:

My Cummins 370hp 6BTA’s are running at different turbo pressures at cruise

 

The Port motor runs at 11psi, 600d F egt

the starboard at 16psi at 2300rpm 800d F egt

The port motor also lags in spool up and a bit more of a puff of black smoke then starboard when getting over the hump.

The port motor has a fuel cooler

The starboard motor does not

that is how they came from Seaboard, 11y apart

The port motor burns a quart of oil every 50-80hr

Starboard is minimal

The port motor spits a little oil through the Seaboard Marine recirculation system, starboard nil

The prop’s were calibrated to Seaboard specs but we are not hitting the RPM’s now due to what seems to be the Port motor not pulling its weight

 

More backstory:  the boat is a 33’ open sport fisher, Dawson Canyon Runner, I bought in 2005

In 2007 I replaced the Port Motor with a recon from Seaboard

In 2009 the starboard motor went south and did the economy

The boat went into dry dock in the Mexico desert

I lost 1/2 my money in the recession,  my now ex took the other half in 2012

Couldn’t afford to keep it, couldn’t sell it, It took a little time to get on my feet

In 2018 we pulled it out of storage and I bought another motor from Tony. 

I have no idea how well the motors were pickled in 2009

In 2019 it was ready for the water,  we found the fuel tank vent hose on the port side was clogged by a mud wasp nest.  A Mexican deck hand replaced the fuel vent hose and took out the high point loop.  This set up allowed a few gallons of salt water to enter the fuel tank.

We burned out 2-3 sets of injectors by the time we got this issue cleared. We have a multi step filter system on both motors. The lower turbo pressure issue started after the salt water ingestion

The 2007 port motor has 1000hr

The 2018 Starboard 700hr

we have about 500hrs on her since we cleared the  saltwater ingestion, trouble free except the mis-match turbo pressure 

Just slightly more smoke at startup on port side

Where do I start on diagnostics on this one?

My mechanics down south say to send the injection pump in for calibration and the turbo in for “service” and adjust the valves

They also suggest a Mexican Stress test, run one motor at full throttle while the other is in neutral, then alternate, and see what RPMs each one will make on its own.

What do you guys think?

on an aside, she sure can fish, we picked up a 75lb Dorado yesterday

Topic

[Rob Schepis]

Here’s some further info as to the turbo inspection and the low power

What a Marine Diesel Turbo should look like when Inspected

Understanding Low Power Troubleshooting

[Tom M]

 

here

 

I found Tony Tips for this

 

i will start there 

[Tom M]

I won’t be me personally that will take a look 

what should we be looking for? is there a checklist? or good you tell me a few things to look for?

thank you for your help BTW 

 

 

 

[Rob Schepis]

Your photos are attached.  Yes I would remove the elbows and inspect the turbo outlet.

 

[Tom M]

pics

[Tom M]

I tried to attach pic’s – let see if it opens 

the problem started directly after we got the salt water ingestion cleared, about 500hrs ago 

The exhaust has not  been removed since 2007 nor the turbine inspected 

 

should we start there?

 

T

 

[Rob Schepis]

Well that’s a lot of info, thanks for that.  Info is important but let’s also start with some good photos of both engines and be sure to include the exhaust systems on both engines.  When did this condition start happening? When was the last time the exhaust was removed from the turbo outlet for an inspection of the turbine ? 

[Author]

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