Motor noise

[cooly]

Any motor guys out there? I bought a 32 Sportfish with Low Hour 8.1 Captain Choice Crusaders 2005 year (75 Hrs) out of warranty. My port engine has started to make a clanking sound at low rpm's. Oil pressure and temp within specs. Not sure where to start other than calling a mechanic which I will probably do for piece of mind. would water in fuel make this happen ? Any input would be great

Thanks

[witeagle]

If you bring up the RPM a litle while the boat is not in gear do you ge the same noise?

[cooly]

noise seems to go away at speed. I normally hear it when docking low rpm's 650 700 in gear or out of gear. saw something online about piston slap, sounds expensive.

[Douglas Fairchild]

Take a large screw driver. Start engine and be mindful of your belts Place tip on each cylinder area and put your ear on the other end. See if you can find where noise is loudest. If you find that area and its in the area of a cylinder wall. Shut off engine remove spark plug put a wooden dowl rod into the hole. Put the rod straight in until it is resting on piston. Place a wrench on crank shaft bolt. It will be easier to do this if all plugs are removed. Turn crank back and forth to see if there is any slack between crank movement and piston movement. There should'nt be any slack. If there is you have damage to connecting rod on either end, crank or piston end or both. If cylinders check OK remove valve covers. Check for broken rocker arms/valve stems. Use starter turn over engine check for equal movement of rockers and valve movement. Cut open oil filter with metal cutter DO NOT USE A CUTTING TOOL that will leave metal material in filter. Check inside filter for metal debris. If you find some you have serious problems in engine. Let me know what you find. Doug

[cooly]

Thanks will give it a try and post any updates

[fishn luhrs]

I've got the same engines with 250 hours on them. I get an intermitant clank clank at idol. Can't seem to figure it out either. had several people look at it no one knows where the noise comes from.

[skippr]

Some risers have a butterfly in them that will clatter at very low idle.

Fairchild gave sage advice, use a handle of something as a stethescope to isolate the noise. I also would then cut open the filter and inspect.

[Kevin&Cyndi]

Funny thing is my right engine does the same thing. I am only 15hrs beyond a complete oil analsyst which so nothing out of the ordinary. Makes me lean toward riser or mounts. I too have not found the source