Haydn Coolant Alarm - Mk3 vs Mk1

[Ron Miel]

Come on guys, Don't lower the tone, or if you want to, do it in "Off Message", or on the Russell Brand show - wherever that's going to be now. Your spurious stuff makes it harder to read the intended message thread.

[missfixit70]

Hi Kirsty

Thanks. Yes, I realise the different modus operandi of the TM-2 but it DOES claim to be an effective coolant loss alarm, so I'm interested in Haydn's own views on that, bearing in mind his own direct low coolant sensor based alarms.

I've also posted separately this evening to ask if anybody knows whether the Mason Alarm works OK in the V6 petrol Bongo. Dave mason doesn't know whether the same sensor/gauge combo is used in the V6 as in TD Bongos. Do you happen to know? Was otherwise going to buy and try (then post results), although the TM-2 has now complicated the issue.

Cheers

David

Having read through the blurb it will only detect coolant loss by detecting the temperature increase caused by the coolant loss, whereas the coolant alarm will detect the coolant loss before it overheats in a lot of cases.
As has been documented on here, it does not cover all eventualities of coolant loss as the level in the header can actually rise due to overpressure in some circumstances, hence SJ's development of yet another alarm to fill that gap There are plenty of threads on here if you look back through the old topics, that frequently get heated as there are lots of different opinions on this subject May be worth looking back through using the search facility.

[Ron Miel]

Thanks again Kirsty. That is useful info, and concise enough that I don't really think I need to search further.

Apart from my general wish for whatever protection is available, asap, against the well-documented (have read the 'Cooling Probs' Fact Sheet, among other things, of course) Bongo complexity/weakness in the cooling area, ours will be pounding over very high Norwegian mountain roads next summer, and despite the latitude, it gets hot there in July.

That's also going to be remote from the Bongo Brigade, the Bongo Shop (even web access), etc., so if Haydn's own alarms are capable of catching coolant losses before heating is detectable, I'll have one of those !!

Am also tempted now by the TM-2 instead of the Mason but would like to hear if anybody's already tried it.

David

[missfixit70]

At least with the TM2 you have a temp read out, so you can see what's actually going on, There are quite a few in use I think, I'm sure you'll have plenty of responses over the next couple of days, bet you can't wait to get your mitts on your bongo

[Ron Miel]

Understatement of the year, Kirsty! (Hope that's not too spurious )

[haydn callow]

RonMeil...have sent PM.
The TM-2 does NOT detect coolant loss....Not aware of that claim anywhere.

[lindeelu]

To fully protect any engine from overtemperature issues, ideally you need 2 types of alarm.

As most problems stem from coolant loss a low coolant alarm is the first step.

Then there are the other issues which cause overheating which won't activate a low coolant alarm
and can also be missed by a coolant temperature sensor for various reasons,
i.e.: Full header tank, no coolant in the head around the temperature sensor.
Unfortunately by the time you need a coolant temperature sensor, a problem already exists and in all probability
damage has already been done.

Same with a coolant overflow alarm.
By the time coolant starts to be ejected from the header tank some problem has already arisen to cause the problem.

This is where the block or head temperature sensor comes in for disaster avoidance.
It senses the heat in the engine regardless of whether coolant is present or not, but again it will not work until the engine
gets past it's normal upper temperature point.

So the ideal set up is a low coolant alarm for early warning and a block/head temperature sensor for disaster avoidance.

The idea is to warn of trouble before it becomes an expensive problem.

I believe this the setup Haydn uses on his own Bongo.

[haydn callow]

TM2. THE WORLD'S SIMPLEST & BEST SELLING AFTER MARKET ENGINE OVERHEATING & LOW COOLANT ALARM.

That is from the Watchdog website.

Not strictly true and not what I have ever claimed. I suppose you could argue it would "alarm" if it overheated due to coolant loss but it does not detect coolant loss in it's own right.
The "HAYDN" (Engine Saver) Low coolant alarm detects coolant loss and the TM-2 (Engine Watchdog)detects Cylinder head temp.
It's as Kirsty said above.

[mikeonb4c]

Turning right last night, I became aware of a whistling sound in the cockpit. I quickly clicked it was the low coolant alarm indicating that the G force of the turn had pulled the coolant level below safety at the sensor position in the tank. It had not happened before. It seems likely I've lost a little bit of coolant. Perhaps a v minor leak. But I have tons of early warning and can now start investigating without worrying too much having the Bongo in normal use. First time it has gone off since fitting it over a year ago. The low coolant alarm gets my vote - every time (and, on long journeys, carrying some water so you can carry on in the event you get a slow leak). And I agree with Oz - an engine block alarm seems the next best one to fit. But the Mason Alarm is a good cheap alternative I think provided whatever goes wrong doesn't involve coolant loss around the Bongo coolant temp. sensor area.

[Ron Miel]

Haydn, thanks for PM, and your subsequent post here acknowledging the over-stated sales blurb on the TM-2 site. In fact, it says much more, viz:

"TM2 IS THE ONLY ALARM UNIT THAT CAN RAPIDLY DETECT ALL CAUSES OF ENGINE OVERHEATING, NOT JUST COOLANT LOSS - INCLUDING

- RAPID COOLANT LOSS - LEAKING HOSES - COOLANT BLOCKAGES - POOR WATER CIRCULATION - RESTRICTED AIR FLOW AND EVEN HEAT BUILD-UP FROM OIL SYSTEM FAILURES"

As you say, it really just detects engine block temperature, pure and simple (and that's good), although they do also claim that fitting the sensor under a thermostat fixing bolt will specifically detect coolant loss. That's why I originally asked how reliable you think that would be versus your own coolant loss alarms.

Reckon I know the answer now, and thanks also lindeelu for clearly summarising that for all, and mike for his input.

Would still appreciate direct Bongo owners' actual TM-2 experience, if Kirsty would unlock the separate topic I tried to start to ask for that.

Cheers all

David aka Ron Miel (= honey rum, my favourite Canary Islands tipple.)

[sparkymik]

RonMeil...have sent PM.
The TM-2 does NOT detect coolant loss....Not aware of that claim anywhere.

Yeah I agree, I have fitted a TM2 and they are good, the temp is constantly updated on the led readout, I don't have a coolant level alarm tho, but thats a personal choice the TM2 will also monitor oil conditions but sounds off on startup but you get acustomed to that

Sparky

[dandywarhol]

Turning right last night, I became aware of a whistling sound in the cockpit. I quickly clicked it was the low coolant alarm indicating that the G force of the turn had pulled the coolant level below safety at the sensor position in the tank. It had not happened before. It seems likely I've lost a little bit of coolant. Perhaps a v minor leak. But I have tons of early warning and can now start investigating without worrying too much having the Bongo in normal use. First time it has gone off since fitting it over a year ago. The low coolant alarm gets my vote - every time (and, on long journeys, carrying some water so you can carry on in the event you get a slow leak). And I agree with Oz - an engine block alarm seems the next best one to fit. But the Mason Alarm is a good cheap alternative I think provided whatever goes wrong doesn't involve coolant loss around the Bongo coolant temp. sensor area.

Can't think of any reason that only the area around the sensor would be low in coolant - by the time the coolant level drops to below the sensor the system will have lost a fair bit of coolant...............................................

As to the TM2 - I reckon it'd be a good bit of kit but there's enough happening to keep my eyes on when in traffic, I was trained to keep a watchful eye on mirrors/gauges/road ahead in a constant scan - whether I'd see the TM2 creeping up on me is debatable

[Ron Miel]

Useful inputs Sparky, thanks.

DandyW, agree about the mirrors/gauges/road scan - and, of course, the Mason temp alarm lends itself to that, by directly modifying the existing Bongo temp gauge.

However, I reckon you don't normally need to include the separate TM-2 digi-read-out in a regular scan (although, if it could be mounted somewhere to make that possible, rather than under-dash, why not do so) - as its primary initial use is to accurately check what the temp range and temp max are under "normal" engine operations, for the user to then set an alarm threshold to suit. However, under heavy engine load conditions (up mountains, towing heavy, etc.), I would darned well scan a TM-2, even if I were sitting on it

The lower cost, and clearly well regarded, Mason Alarm is surely great, once you get the alarm threshold set correctly. However, I suspect that the Bongo temp gauge itself is too small scale and too crude a display to compete with a direct digital readout, at those times when you really do want to accurately monitor engine temp variations - and not just respond to an alarm if/when it increases to the alarm threhold.

For that reason, and after all these useful inputs thanks (plus PM help from Haydn), I'm now going to splash out on both a Mark 1 Haydn alarm, and a TM-2.

Thanks Forum!

[teenmal]

Turning right last night, I became aware of a whistling sound in the cockpit. I quickly clicked it was the low coolant alarm indicating that the G force of the turn had pulled the coolant level below safety at the sensor position in the tank. It had not happened before. It seems likely I've lost a little bit of coolant. Perhaps a v minor leak. But I have tons of early warning and can now start investigating without worrying too much having the Bongo in normal use. First time it has gone off since fitting it over a year ago. The low coolant alarm gets my vote - every time (and, on long journeys, carrying some water so you can carry on in the event you get a slow leak). And I agree with Oz - an engine block alarm seems the next best one to fit. But the Mason Alarm is a good cheap alternative I think provided whatever goes wrong doesn't involve coolant loss around the Bongo coolant temp. sensor area.

Can't think of any reason that only the area around the sensor would be low in coolant - by the time the coolant level drops to below the sensor the system will have lost a fair bit of coolant...............................................

As to the TM2 - I reckon it'd be a good bit of kit but there's enough happening to keep my eyes on when in traffic, I was trained to keep a watchful eye on mirrors/gauges/road ahead in a constant scan - whether I'd see the TM2 creeping up on me is debatable

Hi Dandy,I think it beeps?

[haydn callow]

Regarding the TM-2 "oil sensor if you connect" sounding off on switch on. It comes on whenever the oil light comes on. This can be annoying so I put a dash switch in the wire so I can turn off till I get going. Very simple mod. I'ts worth connecting into the oil as if you miss the light flickering it will give sound as well.