Boat hit 200 degrees engine temp

[Anthonym2]

I have a 2007 sea ray 185 sport IO , merc, alpha one drive.
Engine alarm went off today at idle. I shut it on and off 3 times to see if it would quit so I could get it into the dock. Temp would start to rise so would quickly shut it down , temp hit about 180. The third time the alarm stopped so I thought it was working and let it run about 10 seconds but temp still was rising and hit about 200, shut it down and got towed in.
Does this sound like only an impeller issue? or does that high of a temp a good indicator other things overheated, or were ruined? I understand I should of probably not pushed it once the alarm went off....hard lesson learned.

 

[alldodge]

Probably, and that's where you start looking

 

[Lou C]

It could be that, these raw water cooled systems depend on a high volume of water in (impeller) and out (exhaust elbows and manifolds)….

 

[tpenfield]

Impeller or a clog in the system.

Check for clogs first.

200˚F is not terrible.

 

[Chris1956]

Thermostats do not last forever. Did you change it? Ditto water pump impeller. The other thing is the rusting/clogging of the risers/manifolds. Saltwater means you are due to change them.

 

[Silvertip]

start with the cheap/easy stuff first. Remove thermostat and check it's rating temp (160, 180, etc). Then drop it into hot water above the opening temp and see if it opens. Suspend the stat in the water, don't let it lay on bottom of the pan. If the stat doesn't open, replace it. Splash the boat and see if the problem is fixed. If not, then go for the impeller, system clog, etc.,

 

[Anthonym2]

Thanks all

 

[Scott Danforth]

At 200 engine temps you have Zero water cooling the exhaust. So your flappers and rubber hose are now toast

Pull drive, do an impeller service. If any vanes missing, do a system backflush and find the missing parts

 

[roffey]

Just as a FYI, I changed the impeller in my outdrive at the begging of last year. I ran it for a year with out any issues. This year when I ran it on the mufs all was still good. I dropped it in the lake and with in 5 min. I started to over heat.. to make a long story short the impeller spun on the shaft. The plastic had cracked. Not hijacking this post just adding my 2 cents, change the impeller first and see if it still over heats. Work your way up from the outdrive.

 

[Scott06]

Just as a FYI, I changed the impeller in my outdrive at the begging of last year. I ran it for a year with out any issues. This year when I ran it on the mufs all was still good. I dropped it in the lake and with in 5 min. I started to over heat.. to make a long story short the impeller spun on the shaft. The plastic had cracked. Not hijacking this post just adding my 2 cents, change the impeller first and see if it still over heats. Work your way up from the outdrive.

Use OEM merc impellers , read a lot of comments like this where rubber separates from shaft sleeve… i assume yours was aftermarket?

 

[Lou C]

Yep I always use OEM for mission critical parts like impellers & driveshaft bellows. This philosophy has worked well for me with 20 years of saltwater boating & no failures of either.

 

[roffey]

Use OEM merc impellers , read a lot of comments like this where rubber separates from shaft sleeve… i assume yours was aftermarket?

you are 100% correct and lesson learnt, replacement impeller was OEM. It is a PIA to take the outdrive off.

 

[Scott06]

you are 100% correct and lesson learnt, replacement impeller was OEM. It is a PIA to take the outdrive off.

What brand was the offender? Just so folks don’t buy it …

 

[roffey]

What brand was the offender? Just so folks don’t buy it …

It was a Amazon purchase. I will look it up and post it tomorrow, I'm at work, lol. I got new anodes at the same time... had to replace those as well. Sometimes when you think you are saving money, your not.

 

[Scott06]

It was a Amazon purchase. I will look it up and post it tomorrow, I'm at work, lol. I got new anodes at the same time... had to replace those as well. Sometimes when you think you are saving money, your not.

Anodes keep an eye on it if you have a ss prop.. I boat ones at boat zincs.com … had a bunch of corrosion around prop housing . Swapped for oem merc ones seems to make issue go away