Cooling fans

bigdaddycain · Post by **bigdaddycain** » Tue Feb 26, 2008 11:05 pm

dandywarhol wrote:I think you guys should apply for design engineers jobs with Mazda cos it's obvious that the current designers have no idea what parameters to set sensors to....................

That's what its all about dandy...Consider all the bongo additions/solutions that have come from this forum, i bet owners in japan haven't this much technical support from mazda!

We recognize a problem together, then somebody comes up with a solution, we all try it (bench test it if you will), report back,then its tweaked,tuned etc.... You gotta love bongo fury aint ya?

coco bongo · Post by **coco bongo** » Tue Feb 26, 2008 11:30 pm

I'll do anything that works, Safeguarding the bongo and it's new head is my priority.

At least ive got the missis car to use a bit more now so i can spend more time getting the Bongo spot on.

I will cross it by my mechanic to see what he says, at least he wouldnt charge hardly much for quite a simple job. Always helps to have relatives with all the kit and the know how

.

Be good to see that temp gauge go back a tiny bit more!.

bigdaddycain · Post by **bigdaddycain** » Tue Feb 26, 2008 11:46 pm

Good man coco...my sentiments exactly...

coco bongo · Post by **coco bongo** » Sat Mar 08, 2008 9:33 pm

Spoke to my mechanic the other day, and got quite a suprising result on this one, regarding the manual override.

He's usually the sort of bloke to poo poo it, or if it would do more harm than good would tell you so.

But he said as long as your switch is idiot proof so you know when it's on, and only use it sparingly. To stop the fans from burning out.

He also said the front fans and the scavvy fans could be linked to the switch so you can have the best of both

. with the use of a relay as well.

Next time it goes up, It's getting done. I have also found an illuminating blue rocker switch from mill auto supplies.

I will let you know how it turns out.

mikeonb4c · Post by **mikeonb4c** » Sat Mar 08, 2008 11:11 pm

Excellent Coco - I thought it was an exciting idea, good to know the professionals have given it the thumbs up. Must do mine before summer. Keep us posted on yours.

The Great Pretender · Post by **The Great Pretender** » Sat Mar 08, 2008 11:38 pm

Still learning, didnt know there was a scavenge fan

Never had my main fans come on either, so do the main fans come on when the ignition is off if residual heat biulds up and if they do the scavenge linked to them makes sense

coco bongo · Post by **coco bongo** » Sun Mar 09, 2008 12:35 am

The Great Pretender wrote:Still learning, didnt know there was a scavenge fan
Never had my main fans come on either, so do the main fans come on when the ignition is off if residual heat biulds up and if they do the scavenge linked to them makes sense

My fans only came on just before the head went tits up, so like we say they really only do come on when red hot. You think that Mazda would have been clever to make those fans run at even medium-high temperatures, especially with it being mid engine.

And also before the head went, the fans only ran on after it was switched off for about 10 seconds.

The Great Pretender · Post by **The Great Pretender** » Sun Mar 09, 2008 12:37 am

Thanks coco, food for thought.

ronhud · Post by **ronhud** » Sun Mar 09, 2008 1:59 pm

Hi
Got the Freda Fidgets again today! My son took his family for a drive in my Freda - 2 adults and 2 children. I have a Mason alarm fitted and he told me that when ascending Holme Moss the temp needle moved very close to the line that is just to the left of the H. As I'd briefed him about overheating Bongos he stopped for a while and the ne resumed when ok.

He is using the Freda to go camping in France this summer and will be in the Pyrenees at some stage. Even with all the camping gear I would have thought the Freda would have no probs. So I wondered about the fan not coming on and found this thread. Sure enough after a run of several miles I left the engine running while parked and got underneath with a torch and - fan static. So I removed the console as this thread and located the top of the sensor as described. It looks as though the head should be removable and there is what seems to be a small plastic latch but I'm reluctant to tug away without a bit of confirmation from some one that it should be ok!

Also any comments about fully loaded Bongo on long ascents would be appreciated. And has anyone done the override switch yet?

Ron

ronhud · Post by **ronhud** » Sun Mar 09, 2008 2:04 pm

Just realised that the sensor referred to is for the scavenger fan - whatever that does. How can I check whether my rad fan will work?
Ron

dandywarhol · Post by **dandywarhol** » Mon Mar 10, 2008 12:05 am

IMO if the cooling system is working properly then the fans/sensors do their job as they should. Bringing on the fans at the wrong time leads to an overcooled engine, poorer fuel consumption and increased engine wear.
The fans will come on if you sit at 2,000 rpm in neutral for around 5 minutes on a cool day and will stay on as long as the ignition is on until the coolant temp drops to the predetermined value.

They also come on when the a/c is switched on.

The scavenger fan rarely comes on (I think I heard mine once on a (rare) hot summer day) and is sensed by the engine bay cover temperature.

Why mess about with a perfectly working automatic system by fitting manual overides which could be forgotten about in the pressure/concentration of busy traffic?

ronhud · Post by **ronhud** » Mon Mar 10, 2008 12:15 am

Hi Dandy - thanks for the guidance on checking the rad fan - I'll try that tomorrow. The rest of your message seems to be addressed to the earlier stuff on this thread - however on looking at lots of the threads re blown gaskets, overheating etc there rarely seems to be a suggestion to check whether the rad fan actually 'works when it should'. Thats why it occurred to me that if the temperature is rising when one might expect it not to perhaps its because the fan didnt kick in.
Ron

The Great Pretender · Post by **The Great Pretender** » Mon Mar 10, 2008 12:45 am

At what temperature do the fans kick in dandy?

mikeonb4c · Post by **mikeonb4c** » Mon Mar 10, 2008 1:03 am

I find it hard to believe putting the scavenge fan on could seriously affect engine operating temp. But I might like to reduce the radiant heat into the cab on a hot day. It might also mean I use the aircon less and thus increase fuel economy by the back door. Interested to debate this one as I'm no expert

dandywarhol · Post by **dandywarhol** » Mon Mar 10, 2008 1:28 am

The Great Pretender wrote:At what temperature do the fans kick in dandy?

With the (accurate) Mason mod kit my rad fans come in about 3mm from the "H" if I remember correctly.

I don't know if my 11 year old system is operating as it should but I have no overheating/water loss issues but the gauge does get pretty high under load. It just shows th eactual reading with the Mason rather than a damped and suppressed reading the original gauge shows which won't worry the punters