Bongo overheat spook (worth knowing abiout false alarm)

[Cab-ova pete]

Frank, that sounds an interesting modification, does it not cause any problems elsewhere? I haven't done a big run yet but I'm hoping to be heading Scotland in July? Hopefully I will have a tm2 Haydn alarm fitted before then?

[dave_aber]

99°C is fairly low to set as a warning temperature. I can hit 99°C occasionally when under load - i.e. fast up long hills. Usually sit about 92°-93°, but 99° is relatively easy to achieve. Certainly not worth worrying about. (Temp measured at the rear of the head)

Bear in mind that the system is pressurised, so the coolant can't boil until the pressure is vented unless the temperature exceeds 121°C.

IIRC, my alarm is set around 105°C - at a level which I never see in normal use, and sufficiently below 121° to alert me well in advance of disaster

[BongoBongo123]

99°C is fairly low to set as a warning temperature. I can hit 99°C occasionally when under load - i.e. fast up long hills. Usually sit about 92°-93°, but 99° is relatively easy to achieve. Certainly not worth worrying about. (Temp measured at the rear of the head)

Bear in mind that the system is pressurised, so the coolant can't boil until the pressure is vented unless the temperature exceeds 121°C.

IIRC, my alarm is set around 105°C - at a level which I never see in normal use, and sufficiently below 121° to alert me well in advance of disaster

Good info dave I forgot about the pressure changing the boiling temp. I could probably push it to 100C
I like the extra early warning, safe than sorry etc. The TM2 is not so loud as to make you jump out of your skin, it is the right volume level to make you go... "what's that and then check the alarm"

[BongoBongo123]

Hi all, I've gotten the message now! I have the basic a/c in a 97 diesel, I just thought I was missing something of importance that I should know? I have always been under the impression that using a/c uses more fuel? Fuel is the most important part of the journey to me don't get me wrong I use the aircon on this se hot blistering drives, but mainly keep the windows open, El-naturalo . And yes mikeon I'm hearing you

Driving above 30mph with windows open can cause drag/reduce aerodynamics (if that is possible on a Bongo lol) and therefore burn more fuel. Though the plastic protector things on the bongo front windows guard against that a bit, probably. Better off using aircon I think at 50mph and above.

[Diplomat]

Frank, that sounds an interesting modification, does it not cause any problems elsewhere?....

Not for me, but it might for anyone who wants air conditioning!

It certainly gives me peace of mind when I've been thundering along with a heavy load and suddenly hit a 30 minute stop-start traffic jam going up hill on a hot day. On go those fans, on goes the heater flat out with the windows open. Alternatively put that crimped metal to plastic radiator join to the test as it gets red hot!


Frank

[Cab-ova pete]

Someone should have created a switch or something to do exactly what you have done there frank Thanks for the info

[Diplomat]

Someone should have created a switch or something to do exactly what you have done there frank Thanks for the info

They probably have. I expect the fans also come on after the water temperature reaches danger point. I prefer to start cooling before the radiator seam is put to the test.

Similarly, I believe that one or two members have put a manual override on the engine scavenger fan. I must do that too.


Frank

[Muzorewa]

The switching of the fans as standard is in two stages, in fact the two fans on the radiator are different, different number of blades. I don't know what the temperature thresholds are but one fan kicks in and then both depending on demand.

[mikeWalsall]

Like I said earlier .. it is very rare I turn my AC off winter or summer .. so as soon as the ignition is switched on a fan radiator fan starts .. which uses engine power .. to 'drive' the alternator .. which uses fuel .. but so does turning the radio on .. lights .. heater blower .. heated back window .. reversing lights .. or what ever ..

How far do you go to achieve your goal .. why have some thing to improve comfort / quality of life then disconnect / never use it .. but there again I use LPG which is more cost effective than petrol so helps to pay for my little luxury (?)

I don't drink (how much are a couple of pints or a bottle of wine?) .. smoke (how much are ciggies ?) don't gamble (never been in a bookies in all my life) .. don't chase women (they would have to be very gentle with me anyway) .. don't eat out .. never even had a Big Mac in my life .. don't have a mobile phone (how much are some of those gizmos?) so maybe always having the AC on when driving compensates a little ..!!

[Cab-ova pete]

Sorry to say Mike but you don't know what your missing mate oh your not in prison are you Mike??

[roosmith]

I'm with Haydn on this one, does it make a difference? I'm not convinced on a large engine like any of the Bongos the difference between having the compressor running, rather than just turning would be measurable.

I had a courtesy Citroen C1 1 litre where the air con coming on dragged the speed down, I'm sure you could measure that but I ain't convinced on the Bongo.

Also if you've bought a 2 tonne brick accepting the terrible fuel consumption, why are you then bothered about the minuscule theoretical savings from being cool in the summer and dry in the winter?!!!

[mikeonb4c]

I'm with Haydn on this one, does it make a difference? I'm not convinced on a large engine like any of the Bongos the difference between having the compressor running, rather than just turning would be measurable.

I had a courtesy Citroen C1 1 litre where the air con coming on dragged the speed down, I'm sure you could measure that but I ain't convinced on the Bongo.

Also if you've bought a 2 tonne brick accepting the terrible fuel consumption, why are you then bothered about the minuscule theoretical savings from being cool in the summer and dry in the winter?!!!

I'm with both of you. % penalty is much less on a Bongo than on a super-economy engine, % benefit is rather greater esp for back seat passengers with windows that only crack open a little at the back. Of course the technology on a super-economy engine is arguably less mendable and likely to be more costly than the Bongos more basic mechanics if it goes wrong, so that can offset the benefit of beter MPG also!

[g8dhe]

We measured the impact a couple of years ago on the V6 between Sussex and Lancashire it was a 5% penalty, one I'm prepared to pay!

[Dodgey]

Ac cools air and as part of the process it also dehumidifies it. Very useful for demisting in a hurry.

I only use mine when I need it. 5% is 1.5mpg on mine . I'm not tight but I don't like throwing away money

You can really hear the rpm drop when my ac comes on.

[Diplomat]

Some of us just weren't born to endure air conditioning.

I went to the coast yesterday in a mini-coach and had to take a warm jacket and long trousers for the refrigerated journey!

Warm air brings me long awaited pleasure when summer eventually arrives.


Frank