Overheating issues again

[Philgconnors]

As some of you may know, I had impeller issues earlier this year in June that caused overheating issues. Since replaced my boat has ran great.

Went to the lake on Saturday for a get together, and reluctantly had to beach the boat On super fine sand. Ran good all day and the very last trip had a major overheat. Anytime I put the engine on load, it spikes the temp gauge. Obviously I killed the motor right when this happened and got a tow back in.

Next day I installed a new thermostat as mine is pretty dang old and worn out. Water is pumping from the exhaust but it doesn’t seem like enough. I also found my exhaust bellow was disconnected so I reconnected that and took the boat back to the lake to test it on load. No luck still overheating.

I’m suspecting sand is plugging something up and I’m going to need to pull the water pump and start working back from there.

Do you all have any other suggestions to cure this problem.

Thanks guys.

[Big Block Power]

Pull the impeller. Back flush. Wray engine and boat again is this?

[Philgconnors]

Sorry. It’s a 1999 226 with a 454 mag mpi

[SAB220]

Was your old impeller intact when you removed it? If it was destroyed it's recommended you try to reconstruct the old impeller to verify you have all the pieces. If it sand or pieces from broken impeller you can do what BBP suggests or do what the experts say to do ...pull out the boat & starting removing hoses.

After pulling out the boat, I'd think I use your multi-point drain system first and/or remove one end of hoses to see what you find. Look where the hoses bend. All this assumes the stat and temp sending unit is operating properly or is not blocked with sand? I think I would TRY to drain the water into a bucket/pan for inspection. Maybe you'll find something

[akorcovelos]

Pull the water pump, and replace it even if it looks good. I just went down that rabbit hole and had I just changed the pump (was only a few weeks old) I would have avoided spending a bunch of money throwing parts at it.

[xlint89]

Was your old impeller intact when you removed it? If it was destroyed it's recommended you try to reconstruct the old impeller to verify you have all the pieces. If it sand or pieces from broken impeller you can do what BBP suggests or do what the experts say to do ...pull out the boat & starting removing hoses.

I agree. Was your impeller intact?

When replacing my fuel pump I found 2 "legs" from the impeller in the cool fuel II hose. (previous owner never checked the cooling system).

[rabiddawg]

Pull the water pump, and replace it even if it looks good. I just went down that rabbit hole and had I just changed the pump (was only a few weeks old) I would have avoided spending a bunch of money throwing parts at it.

You are talking about the engine circulation pump right?

[akorcovelos]

Pull the water pump, and replace it even if it looks good. I just went down that rabbit hole and had I just changed the pump (was only a few weeks old) I would have avoided spending a bunch of money throwing parts at it.

You are talking about the engine circulation pump right?

No. Read here to learn from my mistake: https://www.cobaltchat.com/viewtopic.php?f=50&t=4449

[Philgconnors]

I do remember earlier this season that the starboard side exhaust riser and manifold was 10-15 degrees warmer when running than the port side. Not sure if it is related, but I think I’m going to start with Recirc pump. I doubt it’s ever been replaced or worked on.

[Big Block Power]

I do remember earlier this season that the starboard side exhaust riser and manifold was 10-15 degrees warmer when running than the port side. Not sure if it is related, but I think I’m going to start with Recirc pump. I doubt it’s ever been replaced or worked on.

That's normal. Don't go charging that.

[Philgconnors]

So start with the impeller that I replaced at the beginning of the summer?

[SAB220]

akorcovelos - In that other thread did you change the impeller or buy a new water pump to fix the problem? I know the vanes of the impeller need to be curved in a particular direction. Maybe that's how it became a O instead of a D? Last time I had it replaced they had to replace the backing plate also (scored) Also could you comment on the tools you removed the pump because it's touchy feelly with 4-5 inches of room in-front of the pump. I usually have a mechanic do this job along with other items because my body doesn't move in those need directions anymore. I'm thinking you come in from the side.

[akorcovelos]

So start with the impeller that I replaced at the beginning of the summer?

Yes.

[akorcovelos]

akorcovelos - In that other thread did you change the impeller or buy a new water pump to fix the problem? I know the vanes of the impeller need to be curved in a particular direction. Maybe that's how it became a O instead of a D? Last time I had it replaced they had to replace the backing plate also (scored) Also could you comment on the tools you removed the pump because it's touchy feelly with 4-5 inches of room in-front of the pump. I usually have a mechanic do this job along with other items because my body doesn't move in those need directions anymore. I'm thinking you come in from the side.

It was installed correctly, I’m guessing it got starved for water long enough to seize in the housing and strip the hub. The kit comes with a new housing, impeller, hardware, and wear plate. Depending on the bilge layout you can either take the housing off from the rear of the pump if you can access it. Other option is to remove the whole pump and service it on a bench.

If you don’t know the service history on the boat I’d opt for the latter and pull the whole pump. That’s how I found a failing sea pump and bearings.

Both options can be done with basic hand tools. I just pull the starboard batteries and beauty panels and can get at the pump with relative ease.

[Big Block Power]

I also think he's wondering why you replaced the water pump.