HI we have just bought our first bongo. its a 1997 2.5d aft. there doesnt seem to be much wrong with it but one thing i have noticed is that the temperature gauge drops when travelling above about 30/40mph. its off the gauge when driving on the motorway and the heaters are cold. driving around town it varies between cold and about 11 o'clock on the gauge depending on traffic etc but the heaters remain hot. there is also a very minor leak on the bottom front rad hose which i will replace as soon as possible.
i assume the thermostat is stuck open and i am happy with changing this myself but i need to look into the flushing and bleeding routine. has anyone else had this problem and how did you solve it?
all advice/tips greatly appreciated
temperature
Moderators: Doone, westonwarrior
Re: temperature
Once the engine has warmed up the temp gauge should remain steady at 11 o'clock. You need to get this sorted as soon as possible. The thermostat will need replacing as well as the bottom radiator hose and the coolant system will need bleeding. Before you do anything watch these 3 videos:
https://www.youtube.com/watch?v=jRAKOSxgbKo
https://www.youtube.com/watch?v=jRAKOSxgbKo
668. The Neighbour of The Beast.
Re: temperature
Thanks for the quick reply.im going to order a new, genuine thermostat and rad hose to replace and hopefully that will solve the issue. i need to send an email regarding my membership/discount on the shop as my paypal email address is different to my forum email address, but thats another issue
Re: temperature
And whatever you do Do Not Drive It until it's sorted.
If you do the head will crack.
Once sorted you will enjoy many years of happy Bongoing, and like lots of us, make many great friends.
If you do the head will crack.

Once sorted you will enjoy many years of happy Bongoing, and like lots of us, make many great friends.

- Northern Bongolow
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Re: temperature
From the description of when it happens I would suggest you check the temp sender carefully. The top connector can get dirty or the rivet comes loose. Or the wire to it over the front of the rocker cover is pulled tight. Also copy sender's are not as accurate as the gen mazda sender's. Loose or bad connections alter the resistance read on the gauge.
Failing that pull out the Speedo cluster and look for modifications. Could be someone has modified it with a resistor, if you fit different size resistors you make it read what is pleasing to your eye and brain.
Failing that pull out the Speedo cluster and look for modifications. Could be someone has modified it with a resistor, if you fit different size resistors you make it read what is pleasing to your eye and brain.
- mikeonb4c
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Re: temperature
Assume (with leaks about) you're checking the header tank level and not letting it get low?
Re: temperature
Yea I am. I've barely driven it so far and don't plan on using it again until I've replaced the necessary parts
- mikeonb4c
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- Joined: Sun Nov 05, 2006 10:49 pm
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Re: temperature
Excellent. Hopefully it'll all get sorted without a big outlaypud wrote: Mon Jul 30, 2018 1:42 pm Yea I am. I've barely driven it so far and don't plan on using it again until I've replaced the necessary parts