Flickering coolant temperature alarm

[Syrah]

Went out for a night sail over the weekend and noticed the coolant temperature light was flickering on our 42ds, and the alarm was making a quiet jingling sound. I think that this has been occurring for some time, but the light is not on bright enough to be visible in daylight. I’d put the sound down to being a general unexplained rattle.

Has anyone had experience with this? I’m wondering if it’s a faulty switch, but not even sure where to look to find it.

Regards

Wayne

[sitara]

Hi Wayne,

I had a loose connection to the oil pressure  sensor on the engine which gave intermittent oil warnings. It was the wire that attached to the sensor - the plug was loose. Could be the same in your case. I think the sensor will be in pipework near the top of the engine. I assume water flow out the exhaust is OK.

Rob

[ChrisD]

When was the exhaust elbow last checked?

Over time this can block and cause overheating.

[Syrah]

Thanks Rob,

Greetings from one of your neighbours (G5). I think it’s probably something like that. I don’t think it’s overheating and the light isn’t visible in daylight. I’ll see if I can find and tighten the connection when I’m down there next. I’ve found a diagram, so I think I know where to look.

Thanks Chrisd, I replaced the mixing elbow about 12 months ago.

[zaphod]

That definitely sounds more like a loose connection than an actual engine problem. Locate the temperature switch or sensor and check the electrical connection, and then trace the wires back looking of any damaged sections. It could also be a bad temp sensor.

I assume you still have normal water flow out the exhaust...

[Syrah]

The raw water impeller was replaced about six months ago and flow out of the exhaust is as expected. I think I’m going to be looking for a connection that is loose somewhere.