High-pitched alarm sound & high temp at high RPM
 

Hi all:

Having a blast with the 1996 Mariah Shabah we bought several months ago... But this past Saturday, out on the lake, when we started to put the throttle down (speed up), it started a really loud high-pitched alarm sound. (It's the same sound that the ignition makes when you first turn on the key.) Then, i noticed the temperature was also climbing really fast. I slowed down and made sure the trim was all the way down, then the sound stopped. The temperature also decreased quickly.

When we started up again, it did not make the sound for awhile. Then, as we started to give it more gas (throttle down about 3/4 the way), the same thing happened. Again, when i slowed down, the temperature dropped and the sound stopped.

Anybody experience similar events, or know what this could be?

Thanks so much in advance.

Re: High-pitched alarm sound & high temp at high RPM
 

Yep, it means there is something wrong.First thing to check is your oil level in the engine and in the outdrive.

Re: High-pitched alarm sound & high temp at high RPM
 

thanks for the reply, mikey... i checked the engine oil level before we set out... it was full of clear oil... however, i did not check the outdrive oil level... can you tell me how i could check, or refer me to an area on this site with information?

again, thanks so much.

Re: High-pitched alarm sound & high temp at high RPM
 

Drive oil reservoir is a clear plastic container located either on your engine block or on the rear bulkhead. Low drive oil levels will cause the alarm to trigger. Sounds like its a good time to invest in a Mercruiser manual. They are available here on our site to our contributing members. Here is a link on how to make that happen.

Re: High-pitched alarm sound & high temp at high RPM
 

great info, mikey... on the oil reservoir & membership/manual ...thanks!

Re: High-pitched alarm sound & high temp at high RPM
 

I don't know these systems well, yet, but I tend to think low drive lube wouldn't cause the rapid rise in engine temperature. I'm thinking impeller. It's working well enough when the engine's not working real hard, but as soon as the engine starts working hard, there's insufficient coolant flow.

Jim

Re: High-pitched alarm sound & high temp at high RPM
 

Jim's right. That is another good possibility to look into. If it is beginning to fail that will also trigger the alarm. If the impeller starts to break up, small pieces get ingested into the cooling system causing a blockage. Check the easy one (outdrive reservoir) first and if its okay then the impeller is the next logical choice.

Re: High-pitched alarm sound & high temp at high RPM
 

thanks, guys... i will check both this weekend.