Used 2003 Merc 3.0 w/ alpha 1 OD ... appears to be overheating at higher RPM's

[KiteboardKid]

I just purchased a used 2003 sea ray 176 BR that looked to be in mint condition.
I was told it spent it life in southern California and fresh water lakes.

I was told by the original owner that it had very few hours (less than 100), and he only drove it to church on sunday.
He did say it hasn't been taken out since last year, but its always been garaged in his desert area home.

In order to prove it runs well, he started it up in his garage without using water to keep it cool.
I now understand, that was not a good thing.
The engine ran for approx 1 minute while in the garage before he shut it down.
He told me that the initial rough idle & bit of sputter was likely just old gas.
he always put a gas stabilizer in the tank before putting it down for the season.
I took his word for it, since it looked and sounded great from my novice perspective.

Anyway... I drove it home and hooked it up to the hose and its started up fine and seemed to idle fine.
I revved the engine up and let it run for about a minute, then shut it off.
I did notice brown or rust colored dust around the exhaust port when i was hooking up the flushing ears.
I also noticed some rusty water coming out of the exhaust when the boat first started running, but that went away in about 10 seconds.
I did not notice anything out of line with the gage readings, so i thought is was good to go.

I took the boat out to the salt water bay that afternoon, for a test run with the family.
It started up and seemed like everything was fine ... until i brought her up to speed (higher rpm).
I glanced down at the temp gage and saw it quickly rising from 170*F up towards the 200*F mark. The gage tops out at 220* F.
The boat gave no other indication of having any problems ... i just trusted the gage readings.
Owners manual says 160* F is normal.

The temp dropped back down to just above 170* and stayed that way if i stayed to the lower rpm ... driving slow to get back to dock
The engine ran fine and the temp stayed around 170 for the 10 minute trip back to the boat ramp.

I took the boat home and flushed the salt water out and watched the temp gage for overheating.
I kept it in the lower rpm range during the flushing.
Temp hovered around 170-180* F.
It never dropped below 170 until i shut it off.

I am afraid to take it out and test it again, so here I am, looking for some help.
I spend my full budget on a this boat and really don't want to pull our the credit card for some expensive diagnostics or repairs until i get some advise from all of you.

Lots of Questions:

Thanks in advance.

 

[Scott Danforth]

welcome aboard.

starting the motor without water toasted the impeller and probably melted the waterpump housing. time to take the drive apart and replace the raw water pump.

 

[KiteboardKid]

Thanks, I just took it in to the shop and they gave the same comment.

 

[Rick Stephens]

Kite,

Advice - learn these easy repairs and do them yourself. ESPECIALLY as you "already spent your budget". Take your time. Watch the videos in the adults only section on removing/installing Alpha outdrives, replacing water pumps and what not. Go through everything now. I would recommend you go through the whole enchilada before you stick it back in the big pond to the west where breaking down can be deadly. It's one thing to get a tow back on a little lake, quite another to break the rubber band and end up on the rocks with waves. The Pacific can and will kill you.

The 3.0L engine is really easy to work on. It is also fairly expensive on parts since they aren't available off automotive markets. So you want to be certain of your facts. Temp gauges are often reasonable facsimiles of actual temperatures. Often they are far off the mark. Double check yours. Do oil changes, fuel filter changes, impeller inspection and replacement as necessary. While you are inspecting the impeller, check the gimbal bearing and the ujoints. See if the oil in the outdrive has any water at all in it. Pressure test the outdrive. This is a totally new to you boat, you have no idea, and the previous owner may likely have had no idea, the condition of the seals in the outdrive. Test it, since it is new to you, and then go boating safely and less expensively than you would by wishing on a star that everything is fine. There may be $80 worth of rubber parts that replaced will save you in excess of a grand.

Cool thing in all this, is learning how your boat works and is maintained will give you great satisfaction, make your boating a lot more fun, less expensive and best of all, a whole bunch safer. The iboats forum members are always here to help you figure it all out.

Welcome!

Rick