Safe max EHTemperature?

[bangorlad]

Just taken my 2.5D Bongo for a spin to check out the newly fitted Haydn TM1 alarm. There's some decent hills in North Wales and I took it over the Llanberis Pass; the registered temperature just topped the default set maximum of 100C right at the top and the alarm came on for a minute or two as we went down the other side, while the dash temperature gauge never shifted from it's 11 o'clock position.

Does this sound ok? The average run temp seemed around 85 to 90 over more normal undulating stuff.....

[Simon Jones]

Welcome to the forum . The location of the sensor will have a big effect on what readings you get as will how much stuff you're carrying around and the general condition of the cooling system. No two Bongos seem to read exactly the same so what you're really interested in is what is normal for your vehicle. Ideally you want it set to a few degrees above the maximum value you tend to get when it's had a good workout as yours has done. Perhaps leave it on 100C for now and see if it keeps goinging off and then set it a degree or two higher if needed.

[bangorlad]

Thanks Simon.....

The sensor is in the Haydn/Jo recommended position at the back of the block. I'm off down to the Malvern RHS show on Thursday so will have more idea of 'average' running temperature then.....

[roosmith]

As Simon says no two are the same, my sensor is in the same position and is fairly often up into the high 90s while towing uphills. We have the alarm set to 105, as 100 used to go off when stopped after a run however now knowing our Bongo and using the hold button and A/C fans to better effect 98 is the highest "normal" temperature we get now.

[Gefail]

Hello,
Ours tops 96 with the TM4 (sensor bolted as recommended) fully packed but unconverted 2.5td tin top.

[cmm303]

My Bongo got to know Llanberis Pass well last Autumn. I don't have a digital temp gauge but a modified standard gauge so temps are a bit vague, however I'm confident mine was running over 100C on serious hills. As already said, the important thing was that Llanberis was no different and the temp dropped quickly on the downhills especially using HOLD to keep the engine revs up. Neither did it misbehave when, on one occasion, we parked up at the top so it didn't get any downhill to cool off first.

Acknowledging that every Bongo is different, as a rough guide I'd suggest that light running is in the 80s, loaded running in 90s, extreme conditions tipping over 100C.

Mine was definitely operating high on this scale consistently in three years of ownership. A cooling system refurb this year has brought it smack in line with the bottom end of the scale.

[mikeonb4c]

.A cooling system refurb this year has brought it smack in line with the bottom end of the scale.

I think this is SO important, and i've read it a few times. It's not enough to establish what normal behaviour for our individual Bongo is. As this example shows, there is an optimum that any Bongo (of a given type) should be achieving. So what's needed is to have (accurate) standardised measuring equipment with standardised temp sensor mounting positions. Then, when owners compare figures, what the cooling system should be capable of gets revealed.

[helen&tony]

Hi Mike
That's more or less what you achieve with most standard cars...they have a temperature gauge which is fixed in a standard position, and it tells when you're heading for trouble. There's not an awful lot wrong with the Bongo gauge, except that people tend to look at it rising and think "it'll get me home" instead of calling a recovery truck!.....I guess that Japanese drivers have a bit more "nouse" and watch the gauge occasionally....
It's no good modifying a gauge to read over a larger arc, because the same criteria apply....all you've done is show more movement....the gauge STILL doesn't read properly in degrees. Having the Haydn gauge in a fixed agreed position does give you the ability to compare notes, BUT it only does just that, because the way it reads only tells you that one driver may , by their driving style, cause an engine to work harder ....so, in effect, you need the same driver to drive any car you have concerns over, ensure that the tyres are at the same pressure, the load in the vehicle is the same, the same amount of fuel is in the tank, the same air pressure in the atmosphere, the same wind, and so on. Comparing notes is only a matter of curiosity! In order to gauge whether there's a problem, you need to ask what temperatures the engine is designed to work at....and the best guide is the stat opening temperature, as that is required to open at NORMAL running temperature. Anything above that means the system is trying to cool down..
Cheers
Helen

[mikeonb4c]

because the way it reads only tells you that one driver may , by their driving style, cause an engine to work harder ....

Hi Helen. I think the Haydn gauge also tells you whether one engine has a cooling system that is working better than another. I'm fully aware of the differences/other factors you're referring to but my contention is that in a healthy system the temp rises will be less as the healthy system works better in response to temp rise (sensors signalling, rad flowing freely, stat opening, fans coming on etc.) The standard sensor might work fine if it gave an accurate numbers read-out, but i think an engine block sensor is a valid alternative.

All this was brought home to me by at least one owner saying how their engine block was running much cooler since they fitted a new radiator.

Being able to compare quantitative data (i.e. numbers) from standardised equipment surely has to be good, notwithstanding the very valid caveats you make.

[teenmal]

Personally I prefer a Coolant temperature gauge, as most car manufacturers do, the safest / most accurate way to check an engine running temperature is coolant temperature not engine block/head temperature. You can fit this as a Digital type of gauge for very little money, even with a built in alarm.

Just my opinion.

duck

[BongoBongo123]

It sounds bang on, on all accounts 85C-95C on normal roads, 100C on very large hills/mountains. My Bongo used to top out at 100C on the Brecon Beacons 500M hills so I would say this seems ok.

Unfortunately for me that was until an incompetent supposedly "Bongo friendly" mechanic managed to destroy the engine with a Haydn temperature alarm fitted ! Bongo friendly my ar*e.

It beggars belief at how thick and incompetent you would need to be to be able do that.

I would have to say do your own methodical research. I cannot vouch for the list myself after a catastrophic experience through no fault of myself. If you are planning a cooling system overhaul make sure you are CERTAIN the garage knows Bongo's.

I cannot stress this enough now.

There are obviously bullshi**ers who have made it onto that list. At this stage I would say that list is buyer beware. And I would document your vehicle as much as you possibly can in working condition en route to the garage as evidence should you need it. Video the drive to the garage (ideally including your mobile phone connected to a website showing time and date) and your final temperature read out before taking it to a garage. And do NOT accept picking it up at the end of the day near closing time. Drive it around the block after collection, locally, again and again when you leave the garage until you are 100pct sure it is as it should be. If not you can take it back to the garage.

Well, you live and learn don't you.

[cmm303]

already ducking

My engine wasn't overheating and the standard gauge gave the appearance of being perfectly normal, whilst the modified gauge clearly showed that it was running hot. It also showed that the cooling system was working as expected but all just a bit high. I can even say that its light running temperature was 5-10 deg higher than it should have been. Therefore in my view the modified gauge has a real value that the standard gauge did not.

No dispute that an accurate temperature indication in degrees C is more precise, more obvious with its configurable alarm and provides greater ability to reliably exchange notes. Generally better.

now lying flat

[mikeonb4c]

That sounds right Chris - numbers just make it easier for discussion compared to the 'my needle was at about the eleven-thirty position'. Standard damped gauge is no use at all here.

I agree coolant temp sensor should be fine teenmal. I wonder though if engine block temp might give a useful indication of problem over time i.e. heat soak but i"m no engineer.

Standardised equipment comes before comparative testing, is all i'm trying to say really.

[helen&tony]

Hi
Mike
The block sensor is ideal if you don't want to cut into a hose and fit an adaptor, OR simply find a gauge that fits the original tapping. A REAL water temp. gauge... is far better than the original.....damped or un-damped. My preference is for analogue, as the reading is instant without having to stare at numbers . The standard gauge tell you "hot or not hot" and it's about as good as a coloured strip that changes colour with temperature ...it takes very little effort to fit a decent temp. gauge , and it's good to run alongside the Haydn gauge....one tells the water temp. and the other tells if the coolant is actually DISSIPATING the heat....too many factors will affect the heat transference! The cost of the Haydn gauge AND a water temp. gauge will cost very little in comparison to a damaged head....IF IF IF they are read regularly whilst driving!
Cheers
Helen

[mikeonb4c]

That all sounds about right Helen

Our aircraft instruments are generally dials with numbers, which is telling.