Engine temp sensor

[kevo]

Could anybody tell me where to locate the engine temp sensor, i have been told that
this could be the reason as to why my bongo wont change gear until it has warmed up
for twenty five minutes or more. Still have not solved this ongoing problem with the van
and i have not been able to post any threads due to my computer being knackered. I am taking
it in to a garage tomorrow and it would be good if i can give him somwhere to start because
round here you would think you had asked some of them to fix the ss entrprise.

[francophile1947]

I may be wrong, but I thought the gear change relied on the gearbox oil temperature, not the engine temperature.
Have you changed your ATF?(it should be a clear red in colour) - mine was definitely mucky coloured and my changes improved no end when I changed it.

[kevo]

Yes franco ive changed atf,just looking for other possible reasons now.
cheers.

[francophile1947]

OK, pity it wasn't a nice easy solution. Your fuel consumption must be awful if it takes so long to lock up - mine locks up in less than a mile in this warm weather.

[dandywarhol]

The gearbox relies on engine coolant temperature to allow the lockup to work John.

[francophile1947]

The gearbox relies on engine coolant temperature to allow the lockup to work John.

Ta Dandy, must admit I'd never heard of a gearbox sensor

[Grahame at work]

Kevo,

The engine coolant temperature sensor is in the head on the drivers side above the starter between cylinder 2 and 3.

If it is open circuit your radiator fans will be on all the time.

I can not get my workshop manual at the moment but from memory
I think the ECU is looking for 20C as a minimum which is 2.1 volts across the sensor and 1.3 volts when the coolant is at 60C. it may not be very easy to get meter probes onto it though.

If you have a fault of any sensor the ECU will have an error code stored in it. This can be accessed on the diagnostics connector in the passanger foot well. You have to make a short between two contacts and read the fluctuationing voltage code on another. This is explained in the workshop manual that I have not got at the moment - I can look it up in the morning but that may be too late for you. Someone else may be able to without having to look it up - or it may be in the members only section.

regards Grahame

PS good luck at the garage

[kevo]

Excellent stuff Grahame at least he will have something to go at now, cheers
i will post about how it went.

[Grahame at work]

Hi Kevo,

How did you get on?

I have been looking at the manual & circuits again and found a temperature sensor on the gearbox that tells the ECU what temperature the oil is at.

This is located near the output shaft of the gearbox next to the speed sensor. You should get less than 1.3 volts as measured on the ECU terminal if its above 10C. If the sensor is actaully faulty you should have flashing glow plug & hold lights.

regards Grahame

[dandywarhol]

I got that one wrong Sorry Franco - good one Grahame! ........got me thinking about other circuits now - I thought the 'box used the coolant sensor because the glow plugs knocked off exactly the same time as the lockup kicked in................

[Grahame at work]

And I didn't know that Dandy.

We all learn from this forum - that is what makes it so good

Regards Grahame

[kevo]

Hello grahame and co.
Had no joy at garage he said he put his diagnostic thingy on but it
didnt have a setting for a mazda bongo, he said take it to a gearbox spealist but i have already done that and they said the problem looks like it could be an engine fault somewhere.
I am absolutely fed up, nobody round here seems to want to have a good look at it I have had this problem for a while now and i dont know what to do next, we were hoping to have a few trips out this summer but it puts you off going anywhere while its still playing up.
everyone on here has been great but my problem is that i dont really have a clue about
cars, i have done a few bits and bobs that have been mentioned but some of the other things
i wouldnt know where to start first. I think i will have to try and find someone who is familliar
whith the mazda bongo even if i have to travell to do this. Any advice is greatly appreciated.
Cheers kev

[Grahame at work]

Hi Kev,

Sorry you didn't get anywhere at your garage.

I think you need to check out the ECU for error codes and this may not be as difficult as it sounds.
There is a fact sheet in the members area that gives a method and a list of code descriptions for the auto-transmission. All you need is a short length of wire to do this.
The fact sheet does not cover all the possible fault codes so if you find there is a code reported by this method but is not listed then there are some others in other threads on the forum and more in the workshop manual - you will just need to ask if you can't find the description - someone will know.
Some codes will not be shown by flashing lights and to see those you will need a volt meter, or something that shows the presence of voltage, connected to another connection on the diagnostic connector.

Don't despair
Regards Grahame

[kevo]

Thanks for the encouragement grahame i will give it my best shot but like i said i am a complete novice when it comes to cars, if nothing comes of it and i cant suss it, i think
i will have to go down the route of finding someone who knows what they are doing.
Cheers kev