Incorrect install of water heater leading to engine running hot?

[drivehard]

Boat: 1997 Formula 27PC - twin engine 5.7LX with Bravo 3's

Condition: Port engine runs 10 to 15 degrees warmer, with a few psi less oil pressure

I have changed the raw water pump and thermostat on the port engine, condition persists.

This is my first year with this boat, in the service records it indicates the port engine was recently upgraded so that it would circulate water to the water heater to keep the water heater warm while under way.

During my winterizing this fall, I made sure to drain the hot water heater, fill with pink, and also drain the engine side of the water heater. I notice that the lead to the water heater came from the bottom of the block on the port side of the port engine, and returned as it should to the water pump on engine.

I did some digging and realized that the water should be coming from a fitting near the thermostat on the intake manifold, and not from the bottom of the port side of the engine block. Could this error in plumbing of the water heater from the engine be causing that engine to run warmer?

Is it worth fixing (putting it the way it should be)?

THanks!
DH

 

[Alumarine]

What temps are you running on both engines?
Have you tried switch the gauge leads to see if it's a problem with the gauge and/or sender?

I would think If the water heater valve is closed, then those lines wouldn't even come into play.

 

[tpenfield]

It does not sound like the water heater would do all that much to the flow of cooling water. The water heater on my Formula 330 is connected just as you described and no issues.

I would look for other causes first. Is this raw water cooled? Probably could back flush the oil cooler to see if that helps. Other issues could be the exhaust manifolds or elbows getting clogged and preventing flow of cooling water.

 

[alldodge]

+1^ agree, my 27PC is also hooked up the same way. Since you have twins, go behind the helm and swap the send leads on the gauges, it could be a sender or gauge issue and not the motor. The gauges are not that accurate in most cases

 

[Scott Danforth]

are you reading the 10-15 degree difference on an infared thermometer or the factory installed gauges? Same questoin on oil pressure (mechanical gauge or factory gauges) factory gauges cost the OEM less than $5 and are highly inaccurate unless its a smartcraft (J1939) setup