Overheating? Shall I panic now?

Technical questions and answers about the Mazda Bongo

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jackstringer

Post by jackstringer » Thu Mar 13, 2008 10:46 pm

Have you taken the thermostat out to check its working. IRRC put it in boiling water in the house to see if it works. It maybe just your thermostat is covered in crap and wont move.
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Peg leg Pete
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Post by Peg leg Pete » Thu Mar 13, 2008 10:58 pm

I agree about the thermostat, I would check it and if any doubt change it, not expensive or too difficult to change :wink:
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dandywarhol
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Re: Overheating? Shall I panic now?

Post by dandywarhol » Fri Mar 14, 2008 1:05 am

richrich wrote:
smac02 wrote: I today fitted a Mason temp gauge device. The gauge then sat at 1 o'clock at tickover. As soon as I took the Bongo for a run the needle went quickly towards the Hot end of the gauge, like almost on the H. Still no signs of problems or water loss though. No bubbling of the header tank etc.

What do you reckon? Steve Mc
Hi Steve

If it were me, I would remove the Mason alarm - honest :? :?
WHY :?:
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dandywarhol
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Post by dandywarhol » Fri Mar 14, 2008 1:08 am

jackstringer wrote:Have you taken the thermostat out to check its working. IRRC put it in boiling water in the house to see if it works. It maybe just your thermostat is covered in crap and wont move.
DON'T put it directly in boiling water - only tells you it's opening at 100 deg.!
Put it in hot water and heat the water up with a thermometer in the water - should start to open at 80 - 84 and fully at 95. The full opening lift is 8.5mm
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richrich

Re: Overheating? Shall I panic now?

Post by richrich » Fri Mar 14, 2008 7:36 pm

dandywarhol wrote:
richrich wrote:
smac02 wrote: I today fitted a Mason temp gauge device. The gauge then sat at 1 o'clock at tickover. As soon as I took the Bongo for a run the needle went quickly towards the Hot end of the gauge, like almost on the H. Still no signs of problems or water loss though. No bubbling of the header tank etc.

What do you reckon? Steve Mc
Hi Steve

If it were me, I would remove the Mason alarm - honest :? :?
WHY :?:
He said he had no problems, then fitted the alarm. Some people don't like watching fluctuating gauges. That's why I said he should remove it. He didn't have problems :? :?
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Re: Overheating? Shall I panic now?

Post by dandywarhol » Sat Mar 15, 2008 12:40 am

richrich wrote:
dandywarhol wrote:
richrich wrote: Hi Steve

If it were me, I would remove the Mason alarm - honest :? :?
WHY :?:
He said he had no problems, then fitted the alarm. Some people don't like watching fluctuating gauges. That's why I said he should remove it. He didn't have problems :? :?
I see what you mean rich but I think I'd be happier with the alarm doing what it does best than without, even if it shows a higher temp.
I think this particular one's got the start of a blockage somewhere just waiting to go wrong - the alarm will detect when it does. :)
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Ongoing

Post by smac02 » Sat Mar 15, 2008 10:39 am

I see that this is causing some debate. Especially the Mason Alarm. Don't we all wish there was a simple answer to some of the symptoms that mine Bongo is displaying as it is obvious I am not alone. Clearly it is going to be one or more of the following at fault.
Radiator
Thermostat
Water Pump
Head gasket
Cracked Head

I ran her yesterday and as she finally warmed up all seemed well. Temp gauge went to normal. Top hose got hot. Thermostat opened. Bottom hose got warm and all water seemed to be flowing well with no sign of the fans needing to run.

Took her for a run. Temp gauge slowly went over towards 3/4 (Mason Alarm still installed) Fans started to run almost all the time. Got back on my driveway after driving gently. Fans still running like the clappers. Top hose hot, bottom hose stone cold.

I could kid myself that the fans are doing their job and cooling the water but I would still expect there to be some hot water in the bottom hose with the fans running.

To me is sounds more and more like a faulty thermostat. Having said that the pessimist in me reminds me of very similar problems in other folk’s cars that I have seen and that was the head and gasket scenario every time.

Taking advice from the posts I have ordered a new rad, thermostat, water pump anyway. I shall keep you all informed.
coco bongo

Post by coco bongo » Sat Mar 15, 2008 8:38 pm

Brilliant stuff matey, you wont regret it. Sometimes it's a tough pill to swallow but like i said to mrs coco. Our little investment will be better when it's all done.

If you can do all of the replacing yourself you'll save a fortune, i paid £700 for all what you are doing.

About the same for the head, gaskets, and labour, but thats cheaper than most will get it. (usually £1175) all in.

All the best with it, and tell us how you are getting on.
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Post by haydn callow » Sat Mar 15, 2008 9:46 pm

I really don't think you have a problem. The top hose should be HOT (to hot to grip)...The bottom hose should be warm only and you should be able to grip it for ever. I can tow a caravan 200 miles and still the bottom hose is only just warm.
If your stat was stuck or blocked you would overheat very quickly.
The stat could have failed open and is overcooling.
The Mason alarm (as you know) will give a reading towards the hot end of the scale.
http://www.coolantalarm.co.uk
Developer of the Mazda Bongo Coolant loss Alarm
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Post by The Great Pretender » Sat Mar 15, 2008 11:32 pm

Sorry if im missing something here guys n girls, I took my stat out and it had 82c stamped on it. When does it open?
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Post by haydn callow » Sat Mar 15, 2008 11:36 pm

Starts to open at 82 C ?
Fully open at 82 C ?
http://www.coolantalarm.co.uk
Developer of the Mazda Bongo Coolant loss Alarm
Also BMW Clocks
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Post by The Great Pretender » Sun Mar 16, 2008 12:16 am

haydn callow wrote:Starts to open at 82 C ?
Fully open at 82 C ?
Yes but if the bottom hose is only warm after 200 mls it isnt open is it?
smac02

Playing Safe

Post by smac02 » Sun Mar 16, 2008 1:27 am

Haydn,
You're right I'm sure about me not having a problem. But with the obvious potential for head failure I'm playing safe and replacing the items that MAY cause failure in the cooling department. Too many horror stories in the forum for me to take chances.
Though my rad seems ok it's clear that these imported vehicles lead a different life in Japan and some of the coolants seemingly clog the rad after a relatively short time. Also I read that they are generally better maintained than our home vehicles, so why does it seem the coolant is left unchanged
Also have doubts because my fans are running an awful lot of the time which at this time of the year and my light driving style surprises me.

I am still confused about the temp gauge alarm. I cannot find anything that gives a definitive response about what it's telling me.
Should the gauge really be in the 3/4 area of the gauge at this time of the year when the weather is cooler? Yet the alarm doesn't sound when set at No 5? The two seem to be at odd's as to why we install the alarm.
Others say that their gauge never moves from the 1 o'clock area with the alarm installed?

Where will my gauge be when I'm towing in the summer?

Like I said, I'm playing safe even though it's gonna cost. But like others have said, at least I can do the work myself. Also so far the Bongo is easy to work on than many other motors.
I would be interested to hear your comments about the alarm.
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Post by haydn callow » Sun Mar 16, 2008 9:20 am

The stat must be open or you would have overheated long ago
http://www.coolantalarm.co.uk
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Post by francophile1947 » Sun Mar 16, 2008 9:23 am

Your engine should run at the same temperature in summer or winter - that's what the thermostat is for.
The hottest my bottom hose has ever been was lukewarm - there is a feeling that most of the cooling is actually done by the heater radiators.
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