Another Radiator Fan Question

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Les W
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Another Radiator Fan Question

Post by Les W » Sun Sep 09, 2018 10:52 am

Having not noticed the fans coming I did a guick check by turning the aircon on,but only one fan was working so the question is,if one runs should the other ? 2.5 diesel with a cold engine and aircon is not all that good anyway..Thanks in advance
Bonneville
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Re: Another Radiator Fan Question

Post by Bonneville » Sun Sep 09, 2018 5:22 pm

On my 2.0, yes, they run together. I assume the diesel is the same. One of mine had failed but there was a post up here that suggested they worked independently so I ignored it at the time. Check connector, put 12v down it etc.
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Re: Another Radiator Fan Question

Post by teenmal » Sun Sep 09, 2018 7:54 pm

Les W wrote: Sun Sep 09, 2018 10:52 am Having not noticed the fans coming I did a guick check by turning the aircon on,but only one fan was working so the question is,if one runs should the other ? 2.5 diesel with a cold engine and aircon is not all that good anyway..Thanks in advance


No.
Les W
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Re: Another Radiator Fan Question

Post by Les W » Mon Sep 10, 2018 5:40 pm

So it looks like they run independently ? What triggers the drivers side one,I'll put som e power to it tomorrow then it should spin ?
Merlot man
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Re: Another Radiator Fan Question

Post by Merlot man » Mon Sep 10, 2018 6:03 pm

Hello all
On a related note I wonder if it's possible to replace the fans ,both coolant and air con fans , with more vigorous items I.e.to pull more air through ?
It would be important that they would fit into the same old housing as this seems well designed to draw the air through .
We bring our bus to France and their mountains every year so coolant system maintanence and improvements are always on the aganda ! :D
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Re: Another Radiator Fan Question

Post by g8dhe » Tue Sep 11, 2018 8:59 pm

The pair of fans DO NOT work independently, they have dual speed, but both work together, so it sounds like a problem relating to one fan alone either connectors or brushes most likely.
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Les W
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Re: Another Radiator Fan Question

Post by Les W » Wed Sep 12, 2018 7:53 am

Thanks for the help all,and Geoff you've explained it so even I can understand..Cheers
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Re: Another Radiator Fan Question

Post by teenmal » Thu Sep 13, 2018 12:24 am

Merlot man wrote: Mon Sep 10, 2018 6:03 pm Hello all
On a related note I wonder if it's possible to replace the fans ,both coolant and air con fans , with more vigorous items I.e.to pull more air through ?
It would be important that they would fit into the same old housing as this seems well designed to draw the air through .
We bring our bus to France and their mountains every year so coolant system maintanence and improvements are always on the aganda ! :D
Brian






I have done exactly that in the past with vehicles going to work in Mountainous conditions abroad , with thoes particular vehicles it was only a matter of increasing the fan blade capacity.

A wee suggestion , put a baffle between the ac rad and the cooling rad and give them a blast from the front then the rear, remember to remove the baffle when finish.
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Re: Another Radiator Fan Question

Post by mikeonb4c » Thu Sep 13, 2018 10:33 am

Interesting you only increased fan blade capacity teenmal. Was this on engine/fanbelt setups? With electric fans i'm thinking the motor rating is matched to existing fan load/demand and that more wattage would be needed from the motor to drive more blade capacity? If the existing motor is retained it might end up running slower/labouring and - more importantly - less optimally/too hot. On the other hand, if this was on belt driven engine powered fans taking from a huge surplus of vehicle engine power then i can understand the idea, with the fanbelt then being the main item at risk from extra load.

When you say 'give them a blast', is that compressed air you're referring too. Sounds like it might be a worthwhile bit of general maintenance and i might give that a go so thanks for the tip. :-)
Merlot man
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Re: Another Radiator Fan Question

Post by Merlot man » Thu Sep 13, 2018 6:12 pm

Thanks for the replies gents , as Mike asked teenmal do you mean putting a piece of plywood or similar between the rads and the blast being compressed air to clean out the fins ?
As for increasing blade capacity do you mean more / larger blades ? I'd be happy to do that , does anyone have suggestions as to a fan/ fans that would fit in there ?
Would it be a good ides to fit a large kenlow type fan in the front "engine bay " and have it on a simple on/off switch ?
Any and all ideas considered
Thanks in advance
Brian
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Re: Another Radiator Fan Question

Post by Bonneville » Fri Sep 14, 2018 8:02 am

Does your engine overheat when in the mountains? Over cooling is almost as bad for an engine as over heating so I would only look to modify if you are sure you are pushing it beyond the limits of Mazda's intent.
If you do think more cooling is needed, the answer is in the radiator core, not the fans, in my experience. I've only modified cooling systems when stuffing bigger engines in cars not designed for them. In these circumstances the fans are irrelevant, it's all about the radiator core depth. Changing the width/height is usually impossible as you don't have the space so the core depth is increased to add surface area. Another trick was using the radiator from the diesel variant of a given car in a modified petrol one but our Bongos use the same rad so that won't help.
You can get aluminium cores off ebay in a variety of sizes but there are also places like this lot that will take a generic core and weld tanks on to suit the application:

https://www.custommaderads.co.uk
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mikeonb4c
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Re: Another Radiator Fan Question

Post by mikeonb4c » Fri Sep 14, 2018 8:24 am

Bonneville wrote: Fri Sep 14, 2018 8:02 am Does your engine overheat when in the mountains? Over cooling is almost as bad for an engine as over heating so I would only look to modify if you are sure you are pushing it beyond the limits of Mazda's intent.
If you do think more cooling is needed, the answer is in the radiator core, not the fans, in my experience. I've only modified cooling systems when stuffing bigger engines in cars not designed for them. In these circumstances the fans are irrelevant, it's all about the radiator core depth. Changing the width/height is usually impossible as you don't have the space so the core depth is increased to add surface area. Another trick was using the radiator from the diesel variant of a given car in a modified petrol one but our Bongos use the same rad so that won't help.
You can get aluminium cores off ebay in a variety of sizes but there are also places like this lot that will take a generic core and weld tanks on to suit the application:

https://www.custommaderads.co.uk
That seems to make sense. I suppose the thermostat function should prevent over-cooling even if the cooling system is over-efficient (though it may not keep the engine at optimal temp even so)?
teenmal
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Re: Another Radiator Fan Question

Post by teenmal » Fri Sep 14, 2018 11:34 am

mikeonb4c wrote: Fri Sep 14, 2018 8:24 am
Bonneville wrote: Fri Sep 14, 2018 8:02 am Does your engine overheat when in the mountains? Over cooling is almost as bad for an engine as over heating so I would only look to modify if you are sure you are pushing it beyond the limits of Mazda's intent.
If you do think more cooling is needed, the answer is in the radiator core, not the fans, in my experience. I've only modified cooling systems when stuffing bigger engines in cars not designed for them. In these circumstances the fans are irrelevant, it's all about the radiator core depth. Changing the width/height is usually impossible as you don't have the space so the core depth is increased to add surface area. Another trick was using the radiator from the diesel variant of a given car in a modified petrol one but our Bongos use the same rad so that won't help.
You can get aluminium cores off ebay in a variety of sizes but there are also places like this lot that will take a generic core and weld tanks on to suit the application:

https://www.custommaderads.co.uk
That seems to make sense. I suppose the thermostat function should prevent over-cooling even if the cooling system is over-efficient (though it may not keep the engine at optimal temp even so)?




The cooling fan/s are controlled by the ECT and the ECU to keep the engine at the most efficient temp ,no matter what fan configuration , also as you have mentioned the Thermostat. The cooling fans will only operate when they are called for :D
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