Thread: Drilling coolant reservoir for Engine Saver alarm

In the coolant bottle will also tell you when you have one of those nuisance small leaks somewhere and the coolant drops slowly over a week or so.

For a burst hose that pumps the water out instantaneously,no matter where it is it will alarm.

Not a TD5 but a RV8 - I have the combo engine saver so have the temp sensor on the block and as on my engine (101) the overflow bottle can be full but the engine has no coolant in it so in my case using the overflow bottle is not an option.

In my engine the low water sensor is in the top radiator hose and is very sensitive. For sure if the bottom radiator hose fails coolant exists the engine quickly but not that quick - as soon as the coolant drops just a little the alarm goes off and you have plenty of time to shut down - for sure ignore it and drive on well then its all your own fault. Even at revs the engine will not immediately over heat and seize when coolant is lost but it will not take long.

So when the alarm goes off there most of the coolant is still in the engine and rapidly exiting and when lost the engine will not immediately seize - so if you respond immediately the alarm goes off things should by OK - wait or hesitate, well thats a different story.

Garry

Originally Posted by gromit

Not sure I completely agree.
The bleeder screw being at the top means that a sensor fitted there tells you second the level in the engine is starting to drop. You could possibly get a few seconds earlier warning having it in the header tank depending on the failure mode.
If a radiator hose or radiator failed catastrophically how quick will the level in the header tank drop ?

It's strange that most of the respected low coolant alarm suppliers fit at the top of the engine or radiator, there must be a reason.

I'm not after an argument just trying to work out the best location for the sensor.

I've got an Alisport header tank to fit to my Defender and need to add a low coolant alarm. Best bet would be a sensor in the top hose and also in the header tank.


Colin

The reason why the suppliers fit the sensor to the engine/radiator is because the is the Easy option.

I had my low coolant alarm fitted to my D2a by Whyatts in Geraldton and I am absolutely certain that they would know a damned sight more about a Landrover engine than ANY alarm supplier would and the sensor is in the expansion tank.

Originally Posted by 101RRS

Not a TD5 but a RV8 - I have the combo engine saver so have the temp sensor on the block and as on my engine (101) the overflow bottle can be full but the engine has no coolant in it so in my case using the overflow bottle is not an option.

In my engine the low water sensor is in the top radiator hose and is very sensitive. For sure if the bottom radiator hose fails coolant exists the engine quickly but not that quick - as soon as the coolant drops just a little the alarm goes off and you have plenty of time to shut down - for sure ignore it and drive on well then its all your own fault. Even at revs the engine will not immediately over heat and seize when coolant is lost but it will not take long.

So when the alarm goes off there most of the coolant is still in the engine and rapidly exiting and when lost the engine will not immediately seize - so if you respond immediately the alarm goes off things should by OK - wait or hesitate, well thats a different story.

Garry

A Overflow bottle in your 101 is Not an expansion tank So you don't have the option to fit the sensor there because like you have said it would be useless there, This is Not the case with an engine fitted with a proper expansion tank.

Originally Posted by scarry

In the coolant bottle will also tell you when you have one of those nuisance small leaks somewhere and the coolant drops slowly over a week or so.

For a burst hose that pumps the water out instantaneously,no matter where it is it will alarm.

Tend to agree.
An alarm in the header will tell you the level is low if you have a slight leak. Does it trigger when used offroad though ?

Originally Posted by trout1105

The reason why the suppliers fit the sensor to the engine/radiator is because the is the Easy option.

I had my low coolant alarm fitted to my D2a by Whyatts in Geraldton and I am absolutely certain that they would know a damned sight more about a Landrover engine than ANY alarm supplier would and the sensor is in the expansion tank.

Really ? So no technical reason except that you rate Whyatts....

I'll keep investigating before I make up my mind.


Colin

Originally Posted by gromit

Tend to agree.
An alarm in the header will tell you the level is low if you have a slight leak. Does it trigger when used offroad though ?



Really ? So no technical reason except that you rate Whyatts....

I'll keep investigating before I make up my mind.


Colin

I have already stated my "technical" reasons for having the low water alarm at the header tank.
It is no skin off my nose if you want to fit the alarm elsewhere, It's you 4WD put it where you want

Originally Posted by trout1105

I have already stated my "technical" reasons for having the low water alarm at the header tank.
It is no skin off my nose if you want to fit the alarm elsewhere, It's you 4WD put it where you want

I certainly will once I've researched further.

Your 'technical reasons' are ..... easier to install in the block/radiator and give an earlier warning.

I'm not 100% convinced about the earlier warning. Yes for a slow leak but not sure about a catastrophic failure.
I check the level regularly. I have an original black tank and will be fitting an Alisport aluminium one so it's cap off each time.

Even with a slow leak once the sensor triggers in the top hose as the level drops you still have plenty of water in the system so you aren't going to cook the motor.


Colin

The Landrover designers themselves appear to like the idea of the low coolant alarm being fitted to the expansion tank because that's where they are fitted in the D3/D4's