running hot !!

[tuftyfreer]

hi folks back again need some more help please. After reading many posts on here i decided to fit a mason alarm now im paranoid my bongo is running too hot needle sits at just off the danger area on a good run. i set the alarm at 5 only bleeped once is this right ? if not any suggestions also when should the fans cut in and how can i tell if they are working. ive only had it 5 months and im starting to wonder if i should get rid. i dont want to because its perfect for fishing, mountain biking and surfing which is why i bought it but i really dont want to be stuck on the m5 boiling over been there before not much fun.
cheers guys

[Rhod]

Same with mine. Sits at 1 to 2 o'clock normally, but a good run including hills gets it up close to the top end. My Mason alarm is on about the same setting as yours but has not been set off yet. This seems hotter than most Bongos with Mason alarms show, but no problems so far, so I'm not too worried about it. It's been reading like that since before a new radiator was fitted. I've also changed the thermostat & the systems been flushed. Possibly a build up of crud in the heater matrixes, so I'll probably get around to treating it with a flushing agent & doing a proper back-flush at some point. Meantime I just keep a close eye on the gauge. The only time it really gets close to the danger zone is on a long hill & the temperature drops quickly going down the other side. Strangely enough it seems to run slightly warmer during winter

[Bob]

I suspect it's just a case of getting the Mason adjusted properly.

Nothing has actually changed with your Bongo, so I wouldn't be too paranoid.

Peeps with more knowledge will soon be along.

[missfixit70]

You can't adjust the actual gauge reading on the Mason, may be a good idea to get an actual temp reading from the top outlet hose under the drivers seat (inlet to the rad should be at the same temp plus or minus a degree or two) when it's reading hot, my fans kick in here, whic is I think around 95 degrees on the top hose (it happens so quickly it's difficult to get an accurate reading with a handheld laser temp gauge)



At which point it shoots down to just below the 12 o clock (vertical position) within a few seconds when testing while stationary, normal running for me is just above the 12 o clock mark.

Some people have found their gauge to faulty when the mason is added, but a lot have actually found that once a new Mazda stat is fitted full flush & any problems are rectified (tiny leaks can cause all sorts of issues if the pressure can't build up properly, try a pressure test - http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=38823) the mason modified gauge reads where it should.

If you want to check the rad fans are actually working, switching on the a/c should activate them, or unplug the sensor over the hose that comes out of the rear of the block under the drivers seat that leads to the heaters, that should activate them. Of course that doesn't test the sensor is working, the only way to do that is remove it & see what temp it switches. It could be that it's duff, if your engine is running hot, it could have cooked the sensor?
The fans should not be cutting in under normal type runnning conditions, the heater & rad circuit should easily cope with all but the heaviest loads, or if you're stuck in a traffic jam with no airflow, they should cut in.
Definateley worth going for a proper chemical flush & genuine Mazda stat, too many overheating problems could have been avoided this way , the mixing of incompatible coolants & lazy or duff stats are the biggest engine killers IMO.
You may not have an issue, but worth taking a bit of time to make sure.

If that doesn't make sense blame panda Bob's apple champagne

[mikeonb4c]

I still think its a great shame that something like TGPs water temp sensor (from memory, was it placed in the top hose where coolant exits the head) and gauge isn't more widely used. Plus of course the gathering of data so that there may be some chance of identifying patterns that pint to 'normal' and 'abnormal' behaviour.

Eek - is that the sound of axe-grinding I can hear in the background

[missfixit70]

It's on my round tuit list if that makes you feel better Mike

[mikeonb4c]

It's on my round tuit list if that makes you feel better Mike

It ought to be on mine. I think it is probably the best way to go. Just needs everyone to do it and a website where they can put their readings, then we might be able to do predictive diagnosis

[Mountain]

missfixit70
A full tank of diesel
-
I've fitted temp gauge sensor in the top radiator hose and it's quite interesting to watch.

Once warm it generally sits around 82C. If pushed it will hit 87C but since it's not gone higher since the Bongo has been fixed.

[widdowson2008]

missfixit70
A full tank of diesel
-
I've fitted temp gauge sensor in the top radiator hose and it's quite interesting to watch.

Once warm it generally sits around 82C. If pushed it will hit 87C but since it's not gone higher since the Bongo has been fixed.

That's interesting - about to get data from some tests currently in progress and this is one place we don't have a sensor. (ours is fitted in this pipe run at a point immediately after it leaves the head.)
Can you monitor the readings and let me know? You say it doesn't shift much from 82C - How much?

[Mountain]

Well, chugging along on the flat at around 60mph it may drop to 75C.
Queuing in traffic about 85C. A good hill and it will touch 87C max.
-
Most 'normal' driving it sits at 82C most of the time.
However, I fitted the insert for the sensor half way in the radiator top hose under the bonnet, so the engine top hose temp may be a bit hotter but I presume it will only be by a couple of degrees max as it can't really drop much more than that in such a short distance.
I put it there because it was easy to get to and should give a reasonable indication of max coolant temp. I was also conscious of creating a new potential leak at the join, so I wanted to keep an eye on it! I bought a hose and fitted the sensor first so I could be assured of a good seal.
BTW the fan kicks in about 87C and takes the temp back down to 82C ish in no time. Seems the 82C for the stat makes complete sense after all

[mikeonb4c]

Well, chugging along on the flat at around 60mph it may drop to 75C.
Queuing in traffic about 85C. A good hill and it will touch 87C max.
-
Most 'normal' driving it sits at 82C most of the time.
However, I fitted the insert for the sensor half way in the radiator top hose under the bonnet, so the engine top hose temp may be a bit hotter but I presume it will only be by a couple of degrees max as it can't really drop much more than that in such a short distance.
I put it there because it was easy to get to and should give a reasonable indication of max coolant temp. I was also conscious of creating a new potential leak at the join, so I wanted to keep an eye on it! I bought a hose and fitted the sensor first so I could be assured of a good seal.
BTW the fan kicks in about 87C and takes the temp back down to 82C ish in no time. Seems the 82C for the stat makes complete sense after all

Very interestingto read this. What made you think to install a temp gauge that included a sensor in the top hose - hardly any Bongo owners I know of have thought to do this

[widdowson2008]

Well, chugging along on the flat at around 60mph it may drop to 75C.
Queuing in traffic about 85C. A good hill and it will touch 87C max.
-
Most 'normal' driving it sits at 82C most of the time.
However, I fitted the insert for the sensor half way in the radiator top hose under the bonnet, so the engine top hose temp may be a bit hotter but I presume it will only be by a couple of degrees max as it can't really drop much more than that in such a short distance.
I put it there because it was easy to get to and should give a reasonable indication of max coolant temp. I was also conscious of creating a new potential leak at the join, so I wanted to keep an eye on it! I bought a hose and fitted the sensor first so I could be assured of a good seal.
BTW the fan kicks in about 87C and takes the temp back down to 82C ish in no time. Seems the 82C for the stat makes complete sense after all

From the above info, it sounds (to me at least) that there is not a lot wrong with your system - it seems to be working precisely as it should. If we get similar results from our tests, I shall be very happy.
The only query is the temp at which the fans kick in - I would have expected it to be a little higher. According to Grahame (another guy interested in the cooling system), the fans, which incidentally are 2 speed, should kick in on low speed at around 100C and off about 94C. If the temp gets up to 107C, then the fans will switch to high speed. (I think Grahame got the fan speed/temps from the manual - ECU section) We are going to check this in our tests.
Keep your eye on the data and record it - interesting stuff (and very informative)

[Mountain]

Very interestingto read this. What made you think to install a temp gauge that included a sensor in the top hose - hardly any Bongo owners I know of have thought to do this

Just seemed an easy way to keep an eye on the coolant temp at one of the hottest points. I didn't fancy hacking an inch out of the engine top hose and thought it would be a similar enough temp at this hose. I have a digital gauge in a pod on the dash near the windcreen post. It's staring me in the face, so hard not to keep an eye on it.

which incidentally are 2 speed, should kick in on low speed at around 100C and off about 94C.

My fan figures may be a bit out as its hard to tell exactly when it kicks in....I'll keep watching and listening.

[haydn callow]

Mike said..Very interestingto read this. What made you think to install a temp gauge that included a sensor in the top hose - hardly any Bongo owners I know of have thought to do this

TGP mentioned this quite some time ago and it is indeed a good place to monitor max coolant temp....The problem with doing this is that for the average Bongo owner it is out of the "comfort zone" to remove the hose and then go through all the hassel of bleeding the system...I think it will cost far more cylinderheads than it saves.....Having said that...for anyone who wants to experiement in this area.....I have some small rubber fillits that slip between the Hose and the outlet stub which will allow a thin sensor to sit snugly in a channel and ensure a good seal....And a step further, I have a in hose adapter which fits in the hose (involves cutting the hose) and then you seal with a couple of hose clamps. Both these methods will get a sensor INSIDE the hose but as said....It will involve refilling with coolant and bleeding.....not everyone's cup of tea.

I will photo the adapters so you can see what I'm on about.

[haydn callow]