M 18 diesel worry

[markras]

Hi all.  We have recently noticed a disconcerting high pitched sound coming from our motor at higher revs. No noise is evident at low speeds, but by the time the boat is travelling at 6 knots or so, a pronounced high pitched noise can be heard. Does anyone have any suggestions about where to start looking for the problem?Cheers. Mark Rasmussen.

 

[Jack2438]

If I were you......

I would start by listening. An autopilot or a partner and a calm day would make it easier. Put your ear {safely} into the engine compartment and try to figure it out. It could be a lot of things. Wouldn't it be nice if it were the belt? I had a sound at higher RPM's that sounded like, well, like rubbing your wet finger around the edge of a glass of wine. Turned out to be the bearing and not that big a deal. I don't mean to be mean but wouldn't it be a bummer if it were the transmission? I guess the only advice I would have would be to try to pin point the sound by really trying to listen to where its coming from. Sorry I can't be of more {any} help. good luck, Jack

 

[Paul cairoli]

`Water pump

Hi pitched noise are usually bearings I would start with the water pump on the closed system side ...see if there is any play in the pulley , see if it hot ...fix is easy you can press the old one out using a vise if you need to Hopefully its not an alternator bearing

 

[txsailor]

Check

Check the alternator. I have had this problem before. Don

 

[TJ]

use a stethoscope to pin point source

You can get a cheap one with a long needle probe from an auto parts store. Or use a medical one with only the tube.In a pinch you can use short piece of plastic tubing or even a long screw driver for non moving parts.

 

[markras]

M 18 worry ( Happy Ending).

Hi all. Thanks for the advice. Investigation revealed low oil level in the transmission. Oil top up solved the problem.Cheers from Tasmania. Mark Rasmussen.