Engine Temp Alarm

[SanJuanDreamer]

I have a 98 Mariner with Crusader 454xi.
Has anyone added an aftermarket temp alarm to their engines?
Looking to install temp alarm for the engines but not sure where to install the sensor.

[Viper]

Get the kind that mount to the exhaust hoses. They're an easy install. Short of that, an inline water pressure sensor can be used so that as soon as raw water stops, the alarm will sound but the exhaust alarms are simple units that will sound off before you even know at the helm temp gauge that there's a problem.

[SanJuanDreamer]

Think I found one but the sensor cable isn't long enough.
I emailed them to see if they have a 4oft.
http://www.ebay.com/itm/FAHRENHEIT-TEMP ... 2163457512

[km1125]

Qr Bbpost Think I found one but the sensor cable isn't long enough.
I emailed them to see if they have a 4oft.
http://www.ebay.com/itm/FAHRENHEIT-TEMP ... 2163457512

You can extend those lines with any good-quality duplex wire. Your reading might be a slight fraction off, but for alarm purposes it's not going to matter.

[Viper]

This is more like what I was talking about. It's specifically designed to be clamped on to the exhaust hose. If you contact them, I'm sure they can put a unit together for you with the length of cable you need.
http://aqualarm.net/exhaust-engine-monitors-c-5/20248-exhaust-overheat-alarm-kit-twin-p-12.html?zenid=16d8bff57883363b91452facd873a2ae

[SanJuanDreamer]

I'm somewhat confused...why would I monitor exhaust temp and not engine\coolant temp?
The reason I'm looking is because the engine antifreeze\water pump belt broke and the engine got above 240 before I noticed it. Caused some damage but I got lucky. If I had an alarm, could have been better.

[waybomb]

The coolant water goes out the exhaust.
You will notice the temperature deviation much quicker there.

[Viper]

When raw water delivery fails for whatever reason, your exhaust will get hot immediately after the water stops flowing. This will happen before your engine temp or any alarm for engine temp identifies there's a problem. By that time, you could be melting fiberglass exhaust tees, etc.

Just had an overheat go terribly wrong because of this. Melted a tee and stopped the engine while underway at high rpm before the owner realized there was a problem. If there were exhaust sensors, it would have audibly alerted right away before the engine got too hot. The engine is toast!

You still need to monitor engine temps for obvious reasons but for raw water failure alerts, raw water intake or exhaust monitoring are the best methods of alerting immediately that there's a problem.

[km1125]

Two completely different issues that could cause a problem. The OP's post is about the circulation pump failing, which causes head temperature to exceed specs and cause issues. In that case, the raw water is still flowing to exhaust and exhaust is still very cool.. and probably would not set alarm even if equipped.

The engine coolant temp alarm would have caught that issue but would not likely catch a raw-water-flow problem caused by a bad impeller, partially plugged exhanger, partially plugged intake, etc until it might be too late. The exhaust temp can climb much quicker than the engine temp and could cause exhaust hoses to burst or catch on fire. ( I had one burst just like that)

You really need both to catch the problems either way before any damage occurs.

[Viper]

Qr Bbpost.....The reason I'm looking is because the engine antifreeze\water pump belt broke and the engine got above 240 before I noticed it......

You didn't mention that in your first post. That's why you have your gauges, to monitor engine temp. If your app doesn't have an audible alarm to alert you when you're not looking at your temp gauge, you should install one.

Qr Bbpost Two completely different issues that could cause a problem. The OP's post is about the circulation pump failing, which causes head temperature to exceed specs and cause issues. In that case, the raw water is still flowing to exhaust and exhaust is still very cool.. and probably would not set alarm even if equipped.

The engine coolant temp alarm would have caught that issue but would not likely catch a raw-water-flow problem caused by a bad impeller, partially plugged exhanger, partially plugged intake, etc until it might be too late. The exhaust temp can climb much quicker than the engine temp and could cause exhaust hoses to burst or catch on fire. ( I had one burst just like that)

You really need both to catch the problems either way before any damage occurs.

That's why I mentioned you should have both monitoring systems