Engine Saver

There have been numerous threads on this forum over time.

Try Googling "Exploroz engine saver" and they will all appear.

For what its worth, I wouldn't leave home without one!

I have an Engine Safe EMs500 which is a bit more expensive - but has more monitoring options - see Thread 104675

X2 what Allan B said about the engine saver low coolant alarm. I also have a watchdog TM2 to monitor engine temps at the head.

Another alternative, you could use an Android device, Phone or Tablet with a BlueTooth OBDII transmitter to take all engine readings.

and more Google Play link to software

OBDII transmitters can be brought off eBay for around $20.00 the Android software is free in most cases but a paid for app is between $2 and $5 the OBDII powers up from the diagnostic plus

I utilise my Sony Xperia Z tablet for HEMA mapping, OziExplorer mapping as well as engine management.

As I said, its another method of monitoring and an alternative to buying a specific device.

There are two types of 'Engine Saver' available. One sits inside the top radiator hose and monitors coolant levels and when it gets too hot hopefully brings up an alarm. The other is a thermocouple which is bolted onto the outside of the engine somewhere and watches and displays the temperature.

I see 2 problems with the first choice:
1 If you lose a welsh plug or blow a major hose, the coolant will fall away very quickly and you may miss the event. Once there is no coolant, it won't sense the overheating. (My wife was apsasenger in a car which lost its welsh plug. She alerted the driver and the temp gauge rose slightly, then fell back to lower than normal. No other symptoms other than a bit of water coming from the passenger side hood gap...)
2 Having something electrically connecting the engine to a display could create an earth loop which may induce some stray currents and cause corrosion in the cooling system.

The second choice is the 'Engine Watchdog'(I have this one). It also has flaws. They suggest that you bolt the thermocouple onto the thermostat housing. I had my unit on my old pajero and on that the thermostat was mounted well away from the main part of the engine. Should I lose a welsh plug or burst a main hose, the unit would probably not detect it. I mounted the thermocouple onto an intake manifold stud so that hopefully it would measure directly the rise in the head temperature when a hose burst. That meant that the unit was montoring the intake manifold temperature and when it was cold, it would display anything from 50 to 70 deg C when the coolant was up to temperature. I now have a new diesel Pajero and the unit is bolted onto the thermostat housing as recommended. In both cases, when you stop the engine, there is a heat sink effect in which the indicated temperature rises. OK if the unit is turned off, but it drives me mad when the alarm goes off and the engine is not running. I have set the alarm level just above the heat sink level, but with summer coming on, may have to set it higher.

The choice is yours

I have an OBD monitor as well, which monitors 4 parameters, one of which I have selected as engine coolant. This works well, but does not have an alarm function, so I still need the watchdog. Being on the outside of the thermostat housing, it doesn't accurately monitor the coolant temperature, but is fairly close. Typically, the coolant temp is 85 Deg C and the watchdog shows 81 or if it is hot, maybe 83. I have been towing my caravan and the OBD monitor has shown up to 90 Deg C on a long uphill run, yet the car's temperature gauge barely if at all, so there is a lot of margin left. At that time, th watchdog was showing 84, but it was a cold day at the time. Remember that the car temperature gauge is not linear. From cold (say 25 or 30 deg C) to 85 (middle of the scale) is half of the scale. The top of the scale (red) would be about 110 Deg C, so things move quicker once you get past half way.

Had one on the Patrol for almost 3 years
Best thing ever !

Easy to fit