225 mercury saltwater temperature rising after shut off

[_vn_]

Hi, I just started having this weird problem where one of the engines would start overheating after it was shut off. I was out fishing and constantly moving boat to get a drift so after couple of hours one of the engines beeped an overheat alarm. I tested few times and it would happen every time, temperature climbs up to over 180 right after you shut engine off. When I kept engines running - this was not an issue, both were running equally 122F.
Engine that overheated peeing strongly, matter of fact better then the engine that isn’t overheating.
Any thoughts? Thanks !

[JOE54]

any maintenance history on these engines ????? heat soak is unavoidable , would inspect cooling system components for problems , check out 3.0L forum for more info on your engine with ser number also

[EuropeanAM]

Moving to the 3L forum for you.

Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

[HS03_DD]

I'm here because the same thing happened to me yesterday. Was idling along, turned engine off for a minute or two, went to turn back on and overheat alarm (180-ish on smartcraft).
Sat and let it cool to about 165, then started up and immediately cooled down to the 120's.

This it the first time it's ever happened, so kind of weird.

[JOE54]

I'm here because the same thing happened to me yesterday. Was idling along, turned engine off for a minute or two, went to turn back on and overheat alarm (180-ish on smartcraft).
Sat and let it cool to about 165, then started up and immediately cooled down to the 120's.

This it the first time it's ever happened, so kind of weird.

salt water also ????

[_vn_]

i had some records before i purchased boat, i am doing my own maintenance at the moment. maintenance was done previously - change fuel pumps, some work on lower units and usually themrostats/spark plugs/zincs etc. nothing indicating any overheating.

[EuropeanAM]

Serial Number?

When was water pump impeller and gaskets last replaced?

[_vn_]

last year, i didn't change them this year since didn't have much run time on them. like i said - peeing just fine....

[EuropeanAM]

"Sit Time" can be just as detrimental (perhaps even more-so).