260 water cooling and low pressure problem

[Paul Frazer]

New member and new owner here. We love the 260 we bought last September but we are now having continuous problems with either the low water pressure alarm or high water temperature alarm going off on every trip. Our mechanics have replaced the pump impeller first and then the entire pump. But we still have a problem. I have read that it could be due to too much water going through the by-pass water line rather through the main cooling line to the thermostat housing. Any one else experienced the same and would putting a restriction in the bypass line force more water through the thermostat?

 

[Espos4]

I haven’t heard of anyone doing what you are proposing.

The cooling system works well as designed. I think you need to check your raw water cooling source.

Are the intake holes clear on the lower unit? Any barnacles or growth that would restrict water coming in?

How about the water inlet hose through the transom? That hose can get pinched off due to corrosion. Do some searching on “bravoitis” and you will find lots of information.

 

[Andy S.]

Funny enough my upper unit gears were shot and it was heating the water going into the engine. I replaced the upper and everything was fine. Not sure if that will solve your problem but it solved mine.

 

[dwna1a]

Paul you posted that the pump was replaced but what condition were the hoses in? Sometimes the hoses inner lining will get weak and collapse. In my case the hoses had a build up calcium that cut the flow, kind of like hardening of the arteries. Next I'd look at the thermostate and its housing for restrictions.

 

[Paul Frazer]

It has been a long time, but I thought I would update this issue as it has finally been resolved. In the end my mechanic started stripping down hoses and then the exhaust manifolds - and that is where the problem was. Corrosion product blocking the cooling channels. So new manifolds and risers and it is running sweet. The temperature barely seems to rise now. Expensive to fix but I am finally cruising.

 

[Andy S.]

So happy you resolved the problem. There’s nothing more frustrating than getting out on the water with those types of issues. It destroys your peace of mind which is why you want to get out on the water in the first place.