350 Alpha/Bravo I MerCruiser Alarm?
 

Second attempt trying to get some advice on this one. Would appreciate
any inputs on this problem / solution....

I had an overtemp alarm sound as a result of a damaged seawater
impeller pump on my closed freshwater cooling system. I replaced it and
restarted. I was surprise that the alarm went off again but only when
the RPM were increased. The temp gage was went to normal (1/4) and
stayed there. I rechecked everything I could think of - engine
oil/pressure, outdrive lube, temp and all appeared to be ok. The alarm
will not sound until the engine gets up to temp and I then increase the
RPM to ~1800. After it starts sounding, it will remain sounding until
the engine goes cold and I restart.

My questions a
1) Besides the three items listed above (oil, temp and drive lube) is
there any other thing that will cause the alarm to sound?
2) If I mistakenly mixed the sewater hoses (inlet ond outlet) would
this cause the alarm to sound and would the temp still show "normal"?
3) After I replaced the impeller, the first time the alarm re-sounded
was when I was attempting to adjust the trim, any relation?

Any ideas, inputs or suggestions would be greatly appreciated,

350 Alpha/Bravo I MerCruiser Alarm?
 

"Larry" wrote in message
oups.com...
Second attempt trying to get some advice on this one. Would appreciate
any inputs on this problem / solution....

I had an overtemp alarm sound as a result of a damaged seawater
impeller pump on my closed freshwater cooling system. I replaced it and
restarted. I was surprise that the alarm went off again but only when
the RPM were increased. The temp gage was went to normal (1/4) and
stayed there. I rechecked everything I could think of - engine
oil/pressure, outdrive lube, temp and all appeared to be ok. The alarm
will not sound until the engine gets up to temp and I then increase the
RPM to ~1800. After it starts sounding, it will remain sounding until
the engine goes cold and I restart.

My questions a
1) Besides the three items listed above (oil, temp and drive lube) is
there any other thing that will cause the alarm to sound?
2) If I mistakenly mixed the sewater hoses (inlet ond outlet) would
this cause the alarm to sound and would the temp still show "normal"?
3) After I replaced the impeller, the first time the alarm re-sounded
was when I was attempting to adjust the trim, any relation?

Any ideas, inputs or suggestions would be greatly appreciated,


Check to see if any parts of the old pump are lodged in the cooling system.

350 Alpha/Bravo I MerCruiser Alarm?
 

On 5 Jun 2006 04:48:49 -0700, "Larry" wrote:

Second attempt trying to get some advice on this one. Would appreciate
any inputs on this problem / solution....

I had an overtemp alarm sound as a result of a damaged seawater
impeller pump on my closed freshwater cooling system. I replaced it and
restarted. I was surprise that the alarm went off again but only when
the RPM were increased. The temp gage was went to normal (1/4) and
stayed there. I rechecked everything I could think of - engine
oil/pressure, outdrive lube, temp and all appeared to be ok. The alarm
will not sound until the engine gets up to temp and I then increase the
RPM to ~1800. After it starts sounding, it will remain sounding until
the engine goes cold and I restart.

My questions a
1) Besides the three items listed above (oil, temp and drive lube) is
there any other thing that will cause the alarm to sound?
2) If I mistakenly mixed the sewater hoses (inlet ond outlet) would
this cause the alarm to sound and would the temp still show "normal"?
3) After I replaced the impeller, the first time the alarm re-sounded
was when I was attempting to adjust the trim, any relation?

Any ideas, inputs or suggestions would be greatly appreciated,

When you checked the outdrive lube, did you take the top off and look down
into the bottle? I've had the stuff get semi-solid, stick to the sides of
the plastic bottle. From the outside, the tank appeared full, but the alarm
would go off.
--
John H

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