Temp gauge u/s

[maxheadroom]

well it was a question and it's been answered the TM2 comes with 4 mtrs of cabling so penty of scope for finale position in the engine area, any thoughts ? where can it go that will cover both water and cylinder head?, is there such a possibility? think I need a diagram of how the coolant flows


Sparky

try this link.....

http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=19853

enjoy

[sparkymik]

Yeah! I knew I'd seen tht diagaram, cheers Max shame it's from the passenger side but still very usefull all the same

Sparky

[sparkymik]

Sparky[/quote]

If you fit it on the head put it as close as you can get to an exhaust valve as that is the hottest part of the head. Remember the water temp will be the first to pick up heat from the engine before it gets to the outside of the head.



The blue hose is on the outlet from the head, if you look at your engine you will find it connects to a stub exiting the head.
that is where I would install it.[/quote]

Thats a prrrty picture TGP thanks, I worked out that the TM2 has cost me £74-64 with PP, I checked for replacment sensors they cost £54 for the two and your back with the same gauge, I think the Aussie guy has it beat, I may still try to get the original working at some time, but at least it ain't urgent any more

Sparky

[Aethelric]

Actually,the water temperature and the head temperature are not directly related. At tickover, providing the radiator fan is working properly, the engine stays relatively cool but the water is very hot. When travelling quite fast, the engine gets hotter but the water gets cooler. This may sound strange, but you have to consider the RATE of flow of the coolant. At speed the water is flowing through the engine at about 4 times the rate at tickover, so it has less time to heat up and a greater cooling effect.
If you mount a thermometer on the top hose you will see it happening.
I mounted a thermometer, as a test on the head, around where the TM2 sensor would be placed. The mason modified temperature guage seems to track the head temperature quite closely and has an alarm too.

Dave

[sparkymik]

Hope it's ok to revist this old bone for a chew, my TM2 arrived today from Oz 12 days after paying and it was fitted and working in 3 hours, ran the bus on the drive for about half an hour and it got up to 95deg so set the alarm at 100deg, set off down the A31 to the M27 doing 60-70 mph had to adjust upward the alarm level to 112deg, overall short trip of 40 mls on the way back got up to 80mph had to again adjust the alarm level now set at 116deg, and here it remains I'm sure this is the same setting as reported by another TM2 user, would like confirmation on it if your reading this.
I mounted the sensor in the second right tapped hole on head on the passenger side mounted the TM2 in the large cubby pinched the live from the instument panel fuse (well it is an intrument) and put a 1amp inline fuse to take it down from 15A and used the earth block behind the fuse unit all sounds well, this is a cracking bit of kit and I recomend it to the house

Sparky

[haydn callow]

IMHO..It really does not matter where you put it as long as it is on the head somewhere. Just fit it wherever and then for a few days note the highest temp it records. Then set the alarm to go off a few degrees above this high temp.
What you are after is a warning of when your engine exceeds what is normal. Therefore. where you read the temp is irrevelent.
Mine is under a rocker cover bolt and I have set the alarm for 100C. So far, even towing a c'van we have not been over 96C with the sensor in this position.
I have a infra red temp gauge which is very accurate. Wherever I point it around the cyl head I only get a max of 2C variation.
This weekend I will see what the differance is between the top hose and Cyl head.
The TM2 is a good bit of kit and is accurate.

[haydn callow]

P.S. I also connected the orange wire into the oil pressure circuit. Drove me mad at first when ign switched on. Have now put a switch in so I don't turn it on now untill the oil llight goes off.

[mikeonb4c]

Very pleased to hear you opted for the TM2 sparkymik. Somehow I lost track of this thread so have missed several installments. Must get one myself - just need a neat place to install the digital readout thingie. Now that I've fitted an over-ride switch to my scavenger fan I'd be especially interested to see if it keeps the engine block cooler e.g. when sitting in a traffic jam.

[sparkymik]

Hi lads thanks for rejoining this thread with some good infoshare, It died for a while, I was in hospital last week so not able to keep up. Mike, I mounted in the large cubby on the right so that the cables could exit into the back of the ignition area, this proved usfull as electrical connections abound in there including a very large earthing block up behind the fuse board, think I will also connect the oil light, did you connect to a sensor or to the lamp in the dash Haydn?.
I need this to be right planning to travel through Spain next month to the south and over the Picco's, accurate temp will be important

Sparkymik

[Aethelric]

I haven't got a TM2, but I drove about for a week or so with a thermometer connected to the head and got similar readings as yours. I also noticed that they tracked the Mason modified panel meter very closely if you think of half scale as about 95C and full scale as about 115C.
Anyone else got similar (or contrary) experience?

Dave

[mikeonb4c]

Hi lads thanks for rejoining this thread with some good infoshare, It died for a while, I was in hospital last week so not able to keep up. Mike, I mounted in the large cubby on the right so that the cables could exit into the back of the ignition area, this proved usfull as electrical connections abound in there including a very large earthing block up behind the fuse board, think I will also connect the oil light, did you connect to a sensor or to the lamp in the dash Haydn?.
I need this to be right planning to travel through Spain next month to the south and over the Picco's, accurate temp will be important

Sparkymik

In that case I honestly think a quick, simple and worthwhile mod (as I now know, having done it last weekend) would be an over-ride switch for the scavenger fan. It's useful to know if your engine (bay) is reaching high termperatures but better still to prevent it if possible. Plus the occupants should get a cooler journey too. What do others think?

[dandywarhol]

I've only once had my scavenger fan come on after an ardious climb in the height of summer in the UK.
The height of summer in Osaka is in the low/mid 30s - hotter than here by and large.

I believe the scavenger fan to be an integral part of the Bongo cooling system and it allows the engine compartment to reach an acceptable temperature before venting excess heat to the outside via the engine tray. The engine compartment is well insulated from the interior as standard.

As the thermostat is designed to be on the return side of the cooling system, I believe that the heat soak in the engine bay could play an important part in allowing the 'stat to operate through heat transfer in the engine and cooling system.

Overcooling the engine bay will change this and could allow the 'stat to stay closed for longer, thereby changing the characteristics of the coolant to circulate as it is designed to and POSSIBLY aggrevating the old crud/blockage problems some people are experiencing.

I woud be inclined to leave well alone and enjoy a reliable machine.

[mikeonb4c]

I've only once had my scavenger fan come on after an ardious climb in the height of summer in the UK.
The height of summer in Osaka is in the low/mid 30s - hotter than here by and large.

I believe the scavenger fan to be an integral part of the Bongo cooling system and it allows the engine compartment to reach an acceptable temperature before venting excess heat to the outside via the engine tray. The engine compartment is well insulated from the interior as standard.

As the thermostat is designed to be on the return side of the cooling system, I believe that the heat soak in the engine bay could play an important part in allowing the 'stat to operate through heat transfer in the engine and cooling system.

Overcooling the engine bay will change this and could allow the 'stat to stay closed for longer, thereby changing the characteristics of the coolant to circulate as it is designed to and POSSIBLY aggrevating the old crud/blockage problems some people are experiencing.

I woud be inclined to leave well alone and enjoy a reliable machine.

Phew - interesting and technical. I'm bound to come back with a few thoughts though.

* If the sensor for the scavenger fan has gone AWOL (as things can do on 12 year old cars) then - if what you say above is true - there could bean increased risk of an overheating engine.
* Bongos are operating fine in Russia in v cold temps where its hard to believe the engine bay, even without the scavenger fan on, isnt considerably colder than it would be in, say, Japan. But no issues as far as we know from our Russian chums
* The engine compartment is well insulated (it needs to be!) but there is no mistaking the warmth that comes off it even on a winters days. Flushing out hot air lurking in there really should make the car usefully cooler (I'll have a better idea when a long drive and hot weather gives me the chance to make some observations).

I think its one of those things you have to make an individual judgement on. part of the fun for me in owning a Bongo is trying out stuff like this so I'm gonna go with my gut feeling based on the above. But I agree, its certainly not a Mazda approved mod.

[sparkymik]

I'm resurrecting this old bone again, yeah, yawn as it seems we have some others with the prob, I just got and fitted a new temp sensor from Japtech 'in a bag new' and it still ain't workin, so now managed to find and buy a new meter for the dash off Flea-Bay, if it's still not workin with a new/replacment meter where is the output from the loom at the dash assembly? anyone ???. I have a TM2 works fine and fixing the piece of junk that Mazda fitted has cost more so far

Sparky

[The Great Pretender]

I would just superglue the needle at 11 am.