Engine issue on New to me 2005 Searay 260

Hi everyone I am new here but not new to boating. A little back ground I am 54 live in Panama City, Florida and have been boating since 1980. My other boat is a 1972 Thunderbird Formula 233 I spent 2 years restoring and know every inch of her and can do all the mechanics on those old Mercruiser Pre Alpha drives and old Chevy in line 6 cylinder engines. Because one boat wasn't enough we just bought a 2005 SeaRay 260 Sundancer and starting to really enjoy the cruising lifestyle with the wife and 2 kids.

Ok enough background and if I haven't lost you my problem happened today. Took the boat out and no issues. Planed it out and rode around for about 20 minutes, slowed to trolling speed and cruised around the bay at about 6 mph for an hour when I noticed engine idle went down to 500rpm and would not go any faster. No alarms sounding just engine would not go over that rpm. Took it out of gear and same thing and then it quit entirely.

Put the anchor out and tried starting it and the engine would turn over and for a spilt second sounded like it wanted to fire up but then nothing. While turning over the engine I started checking gauges and noted I had oil pressure, water temp at around 160 and before anyone asks yes I have fuel just over a half a tank . Then I noticed the Smart gauge showing zero psi on water pressure.

All this stuff is new to me and this is the newest boat I have ever owned so still trying to get used to this engine. It has a Mercruiser 350 Mag 300hp tied to a Bravo 3 out drive. It is raw water cooled. I checked the out drive and it wasn't blocked with a plastic bag or grass. I continued trying to start it for about 15 minutes on and off and it finally started and ran. Engine would go over 500rpms now but still showing zero water pressure. I am assuming this is the raw water being pushed up to the engine. Engine water temp still at around 160*. Opened up the hatch and felt engine which was warmed up but certainly not scolding hot so it seemed like it was running at that temp. Ran it back to marina at 1000rpm with hatch open for air flow and watched gauges with no change to water temp, 160* and water pressure zero. Once at the marina had them put boat on the rack and ran engine on the hose. Same result engine temp at around 145* and water coming out where it should but still zero water pressure on the gauges. So any guesses and sorry for such a long story.

Since the engine stayed at around 160 then I would think you had some water flow. Without it temps would rise much higher real fast. My first inclination would be that it was a bad/disconnected water pressure sensor that was showing no pressure and the engine went to a guardian mode to protect it.

-Kevin

Kevin, thanks for the response. I don't have any experience with this engine and computers, sensors but I was thinking the same. I just hate spending money on having someone else figure out what the problem is but I may have to in the end until I get a little experience with this boat and engine.

Hi Mark, + 1 on what KevinC says. I had a very similar issue this spring. ( I have a similar boat as you, '06 260 w/ 6.2 ), turned out to be water pressure sensor. Very easy fix, 10 minutes. Sensor is at behind the engine, on top of power steering cooler, the only sensor in that area , so you should find it easily. Quicksilver part# is 8M6000623, about $138.00 locally for me. Like most folks, I hate just throwing $ at unsure problems, however , it sounds like that's your issue. Hope this helps. oh. ps, make sure there is no corrosion on the connector to the sensor.

With an adapter and a pressure gauge you could verify the pressure before purchasing the sensor. But if you need to purchase those things, maybe just bite the bullet and buy the sensor. There is a run of bad ones out there and your year is likely in the range.

GCHOG, thanks for the response and that sounds like a likely cause. Once I get off I will check that out.

paulswagelock, I wish I had the adapter and gauge and may just go buy it because you can never have enough tools

Amazon prime sensor is $25. Claims OEM...

Mark260DA said:

GCHOG, thanks for the response and that sounds like a likely cause. Once I get off I will check that out.

paulswagelock, I wish I had the adapter and gauge and may just go buy it because you can never have enough tools

Click to expand...

I installed a mechanical water pressure gauge on mine using a brass T that I bought at Home Depot. I got the gauge at a pool supply store (H2O pressure is less than 20 psi, so you don't want one that reads too high or you won't be able to read it. I think my gauge goes to 30 psi max). Total cost was less than $20. The original H2O sensor is on the other half of the T.

It sounds like you are in Guardian mode, but you should be getting an alarm and a error on your Smartcraft gauge to go with the reduced power. My drive had "bravoitis", but I always had at least 2 psi showing on the SC gauge so I doubt that yours does. If the mechanical gauge shows no pressure, post back and we'll talk you through checking for it. Its easy to look for. You need to remove the 2 bolts holding the water inlet housing to the transom assembly and visually inspect the hose underneath of it. I think Garry and Kevin are correct and your sensor is bad.

Been busy and forgot to update.

I received the new sensor, switched it out and still no pressure for H2O showing on the gauge. Ran the engine and it was warm but not hot so the next day we had the boat put in the water and planned to camp out near shell island for the weekend.

I cranked up engine and ran it and still zero pressure but engine warm not hot and no alarms. So I cranked up the generator and after a couple of minutes smelled a burned rubber smell and generator quit with out warning. Lightbulb finally went off in my head so I cranked the generator back up and looked at the thru hull exhaust port for the generator on the starboard rear corner and sure enough no water pumping out just exhaust smoke.

Shut it off and went looking for a mechanic at the marina. It was lunch time and no luck. I lifted the engine hatch and took a look at generator and long story longer saw where impeller housing was at and decided to pull the 4 bolts and hose clamp.

I had already checked and cleaned the little trash basket on both the raw water cooling for the generator and A/C so I knew it wasn’t that.

Sure enough all the blades on the impeller are completely gone. Found them in the heat exchanger hose in let. Cleaned out the debris and accounted for all the missing blades. Bought a new one at West Marine for $35 and back in business and water pressure gauge working and showing pressure. It was the generator not the main engine. Lesson learned and more educated on my boat. So went boat camping and well that’s a whole other saga on owning a boat.

Glad you finally figured it out and it was a somewhat simple fix. I do not think that my generator even shows water pressure through smartcraft.

It's interesting that that generator put the engine into guardian mode. Perhaps the sensor was added as engine 2 to the system and the ECM put you in guardian thinking it was an engine.

-Kevin