Buzzer goes off

Hi,
I have a problem with my starboard riser getting really hot and the port stays warm. I read the posts about this problem and no one seems to have an answer,I tried everything the post writers tried but to no avail. I also have a problem with my buzzer sounding even when then engine temp is 160. The oil pressure is good and the out drive oil is full. I replaced the heat sensor on the t-stat. When I disconnect the heat sensor at the t-stat the buzzer stops. It goes off at around 3000 rpm and turns off when I throttle down.

Re: Buzzer goes off

I read the posts about this problem and no one seems to have an answer,

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Since there is about 4 kazillion posts like that here at iboats, that doesn't really tell us anything. Some are right and some are wrong. Which one did you read?

It would help to know what engine and drive (years, SN's help) you are working on.

Did you change the gauge sender or the over temperature SWITCH, big difference.

When was the last time you replaced the impeller.

Re: Buzzer goes off

Ayuh,.... Welcome Aboard,....

What motor,..?? What drive,..?? What vintage,..??

Has the impeller been changed lately,..??
Did ya pull the risers, 'n inspect 'em, 'n the manifolds,..??

Re: Buzzer goes off

I have a 1998 5.7 mercuiser, Alpha 1 gen 2. The engine serial#0L039055. I changed the over temp switch and it's a new impeller. I checked the risers and manifolds and they are clean. I also changed the t-stat housing and the water pump. Interestingly when I switch hoses at the t-stat, port hose to starboard manifold and starboard hose to port manifold, the starboard riser which usually runs hot is cooler and the the port side riser which was always cooler is very hot. I used a clear hose when I switched the t-stat hoses and noticed the starboard hose from the t-stat housing had a lot of air bubbles. When the over heat switch is disconnected the buzzer does not go off. I used a heat gun to get the temp of the engine and it does not run over 165 degrees but when I connect the over temp switch it buzzes.

Re: Buzzer goes off

The audio alarm sender is set to close the curcuit right around boiling point. 210* or so.
As Don asked previously, are you sure have the correct sender?

Re: Buzzer goes off

The temp switch has a yellow wire that goes to the ignition control module on the distributor. Might want to check if for corrosion or damage at the module.

Re: Buzzer goes off

Does your thermostat housing have the little check ball and spring set-up? If so, I'd suggest you check their operation. The air bubbles in the clear hose concern me. I'm not certain from your description which hose exactly showed air bubbles, but air bubbles should not be in any of the hoses. That could indicate a blown cylinder head gasket shooting exhaust gases into the cooling system, heating up your cooling water and simply replacing cooling water with hot gases, causes a hot spot in your cooling system and setting off the temperature-overheat buzzer. I'd suggest a compression test and a leak-down test. Hy

Re: Buzzer goes off

Does your thermostat housing have the little check ball and spring set-up?

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Nope, to new for those.

Also, if the clear hose bubble test was done on muffs, it means nothing. Muffs pull more air than water. Clear hose tests along with temp tests must be done "In The Water" not on muffs.