Yanmar Running Hot - Seeking Advice

[cariedl]

I was on vacation the last two weeks and on the first day of running the boat, noticed the port motor getting warm, climbing to almost 200 degrees under load. For a baseline the motors typically run about 160. The starboard motor was running exactly that, but port would get warm every time I'd get up on cruise. I figured start with the simple, check the impeller. It was bad, but not terrible, replaced on both motors.

Took the boat out again and a little improvement but when pushed the port engine got hot again. Diesel mechanic came out and we went through what was going, he suggested that algae and zebra muscles (Lake Erie's version of salt water barnacles) could be clogging the intake.

Sure enough, here's what we found when opened up:


So that clean out obviously made a big difference. The engine is running cooler, but still not back to 160. So I told the marina and the mechanic has suggested a few options:
1. Remove the after coolers and oil coolers - clean and reassemble
2. Remove and clean the injectors.
3. Install internal sea strainer to reduce build up of growth

I have an external strainer on the boat, is an internal strainer redundant? Would I need both? Thoughts and input would be greatly appreciated.

Thanks,
Charlie

[Carl]

Sea strainers on the hull can also be loaded with growth...you didn't mention that was checked or cleaned.

I like internal strainers as I can see water flow and clogging.
Down side is its another item to clog, have an issue with. I removed staying with external strainers.

Clean all passages and coolers for debris, rod the tubes.

You mentioned not running at 160, I get that...but have you run the boat in warmer water before?
Water temp can play a role in ability to cool the motors. The early part and late season around here, the cool water temps allow boat to run a few degrees cooler. Likewise around this time of year with sun beating down on the bay, water temps crank up high 70's low 80's giving the boat a bit higher reading on the motor temps.
That may or may not be the case...but something to give some thought to after all the main items are checked.
...and usually it's both motors a bit warmer.

[Charlie J]

that will do it
in the summer she would run 170 175
in the warm water, charlie

[mike ohlstein]

http://overtemp.com

[SteveM]

As Mike suggested...

I had this guy flush the engines. Probably a good idea once a year.

[cariedl]

Thanks guys. The OverTemp guy seems like a great option, but I doubt he would run all the way to Ohio...

[Carl]

Thanks guys. The OverTemp guy seems like a great option, but I doubt he would run all the way to Ohio...

...never underestimate the power of money.

[mike ohlstein]

Call him. I know that he services the entire east coast.

[Tooeez]

I'm not that familiar with diesels, so I need to ask do you have a transmission cooler in the seawater line between the raw water pump and the exchanger? All sorts of junk can get caught on the inlet side, and block the tubes so the water flow is restricted to the heat exchanger.

[MikeD@Lightningshack]

The do it yourself option works also.

http://www.rydlymemarine.com/

I used it on my 6CX's with good results. You need fittings, pumps, wire and buckets and you have to be careful to not make a mess.

Overtemp seems like a nice option if the price is right. It is about a 3 - 4 hour job per side, but there is only about 1 hour of labor once you have the gear setup.

Mike

[Tony Meola]

In the spring I watched the owner of the Viking on the hard near do it on his own. He had a garbage can, and a sump pump. He mixed everything up in the garbage can set the pump in it, hooked it up to the engine and then put the garbage can under his exhaust. The pump pushed it through the engine and what came out the exhaust he caught in the can and pushed it back through the engine.

Then after that process was done he flushed it all with fresh water.

[David Davidson]

I have flushing valves on my intakes and flush with fresh water after every trip. Takes less than 5 mins. No external filter, but internal basket type. No growth at all.
It may be worth looking at fitting these.