Engine Overheating While Leaving Marina

[maxse]

Almost out of the marina and the alarm went off as we were gaining temp over 180. I stopped and got towed back to the slip to be safe.

Ran the engine around 900 RPM at the slip for about 25 minutes and the temp stayed around 155 without issues. The risers were cool to the touch.

It seemed to kick up right after I hit 1500 RPM. I noticed a decent amount of growth on the outdrive. Is it possible this could clog up the cooling system?

 

[Ididntdoit]

yup it could.......when is the last time you took it out? look into trilux to prevent growth

 

[maxse]

So I take it out for at least 5 hours every weekend including last weekend. The marina service folks supposedly painted the outdrive this season with antifowling paint.

 

[scoflaw]

Raw water pump service and exhaust would be the first place to look for an overheat issue, unless the growth has closed off your water pickup on your drive

 

[maxse]

If it was clogged up would it overheat when running at idle?

 

[Espos4]

What were your water pressure readings at various rpm?

At idle?
At 1500 rpm?

If the risers are cool and your engine temp is at 180°, the thermostat may not be opening properly.

 

[Espos4]

Ok. I just took a closer look at you photo...... is that grass growing on your outdrive??

 

[maxse]

Risers were cool when running for 25 min at 1000 RPM. I didn’t get water pressure readings unfortunately.

Yes, definitely looks like grass. Wouldn’t antifowling paint prevent that?

 

[Espos4]

Can’t say for sure about the paint.
But if grass is growing on your outdrive, that needs to be removed first.

I see it’s a 2007, Do you have Smartcraft?
Scroll through the display and you should see water pressure.

 

[maxse]

I was able to get it off with a deck brush. I do have smartcraft so will run it tomorrow and check the pressure.

 

[dpvandy01]

I'd pull the boat out and clean it

 

[Boater420]

It's possible at low RPM's the cooling system was able to pump enough water to do it's job. At the higher RPM's it was not able to get enough water through the pickup and over heated.

 

[maxse]

Looking back at my service to replace the oil pan 4 weeks ago they changed the impeller as they had access and it just made sense to do it at the time. So now I am wondering if it's the pump/thermostat or bigger issue risers/manifold. Seems odd if it would be the risers/manifold if i never made it over 2000 RPM right?

 

[roberteb]

Last week, experienced the same... Same type of 'seaweed', but pickup from water. High temp, overspeed alarm (was towing) and idle speed ok... Noticed different sound, as no/less coolingwater..

Cleaned the intake just from outside, after all fine..

Just remove growth and do a test run

 

[liv2ryde100]

Maybe as u increased rpm more of the grass growing was sucked into the intake passages preventing necessary amount of water to flow

 

[Espos4]

When the oil pan was replaced, did you request any additional services?

Did the mechanic suggest any additional services besides the impeller?

With the engine removed to replace the oil pan, it’s a good time to replace the starter and inspect the water inlet hose for
“Bravo-itis”

 

[maxse]

When the oil pan was replaced, did you request any additional services?

Did the mechanic suggest any additional services besides the impeller?

With the engine removed to replace the oil pan, it’s a good time to replace the starter and inspect the water inlet hose for
“Bravo-itis”

They did change the starter while they had it out. Also, he said they changed something on the exhaust that would prevent water from entering the bilge, some sort of check valve...

 

[Espos4]

Sounds like the “flappers”, they are at the top of the Y pipe, one set on each side, just below the elbows.


Give us some water pressure readings at various rpm and we’ll help point you in the right direction.

We could also use some more background info.....
How many hours on the engine?
How long have you owned it?
Any records of the manifolds and risers ever being replaced?
Who does the winterization?
When was the last time the outdrive was removed and “split” open? (When used in salt water, The lower unit should be removed each year to inspect/clean the water inlet)

 

[maxse]

Sounds like the “flappers”, they are at the top of the Y pipe, one set on each side, just below the elbows.


Give us some water pressure readings at various rpm and we’ll help point you in the right direction.

We could also use some more background info.....
How many hours on the engine?
How long have you owned it?
Any records of the manifolds and risers ever being replaced?
Who does the winterization?
When was the last time the outdrive was removed and “split” open? (When used in salt water, The lower unit should be removed each year to inspect/clean the water inlet)

Thank you for your help. I’m going to get pressure readings tomorrow and will post here.

390 hours on the engine and this is my second season with it. I do not have records of the manifold/risers being replaced and will probably do that in the fall to be safe if that’s not the problem now.

The marina (merc certified) does the winterization along with pulling the outdrive and storing inside for the winter. They perform a full service on the outdrive annually.

 

[maxse]

So before starting (not sure it matters) the H20 PSI read 31.

Initially after starting at idle it started around 25 and worked it’s way down to .5 at about 10 minutes and engine temp at 150. After watching the gauge for another 10 minutes it worked it’s way down to 0....engine temp is still at 150 though.