Rx-7 Water Temp Guage Not Registering

[mr_maj]

Hi everyone this is my first post, a somewhat problematic one in anycase!

Ive recently got an RX-7 its a 1993 Type R with low miles, iv got a problem the standard water/coolant temp guage doesnt register any temp even when very hot.

So iv done a search about the water temp sensors and from what iv found ive gone and stripped out the airbox/pipes/etc to get to where the green plug connector is at the back of the primary water tank, is this the right sensor for displaying temperature indash?

I found that the green plug connector clip was broken meaning i didnt have to push the clip in to release it, it just pulled straight off. From looking and the sensor fitting it appears to be a 19mm nut and seems to be in a very awkward space to allow use of a spanner to remove, its impossible to get a socket onto it due the sensor body.  Can anyone suggest how to go about removing this? That is if its the culprit!?

It wont be possible to start the car to test the sensor as i removed the air pump, alternator, all the air and intercooler hoses,etc. So would there be anyway of testing the existing sensor? The wiring for the sensor is short hence not much to work with if putting in hot water etc.

Any suggestions anyone?

Thanks in advance!

[clive]

Hi and welcome to MRC,

You have found the right sensor, and yes they are a pig to get to !.

Ignore the black one wire sensor directly underneath the green one as this is the fan switch, also the one around the front of the water thermostat housing is the low water sensor.  

Hopefully the gauge is just not working because the plug wasn\'t pushed on properly

Hope this helps

[mr_maj]

Thanks Clive!

Any tips on how to remove the sensor? Il think of a way to connect it back up and test it when its out just to see if i need a new sensor!

MAJ

[Jovic82]

you may be better fitting an aftermarket one as the stock gauge does not show "HOT" until it is normally too late and you have done some damage. they are pretty rubbish by my experience and i would never go by the readings from that alone.

cheers
Nick

[Shyne]

I\'d back Nick with that, it is kind of an "idiot light" more than a temp gauge, by the time the needle moves higher than the point it seems to sit at constantly, you are usually too busy squinting to see the road through the plooms of steam billowing from the bonnet vents!!! Maybe a slight exaggeration, but you get the idea. 8o)

[mr_maj]

I noticed that the fan doesnt kick in and assumed that was because it didnt know how hot the water temp is, if the stock sensor is registering then the fans would work as normal? Or is that a seperate issue?

[Frankie]

Thanks Clive!

Any tips on how to remove the sensor? Il think of a way to connect it back up and test it when its out just to see if i need a new sensor!

MAJ

19mm closed end spanner will do the trick. Removed mine yesterday to swap the thermoswitch for a cooler FC one (97deg instead of 108).

[mr_maj]

Cheers Frankie!

Il give that a shot tomorrow, RX-7 is off road for the time being just dont get time to get it sorted!

[mr_maj]

Just to update, i removed the sensor gave it a quick clean and then heated it up, when connected up the temp guage doesnt move, obviously the engine isnt started but key ignition on. I think it should display the temp setting with key in this stage??

When the sensor is disconnected altoghether the fan comes on, so im hoping this suggests that the wiring loom for the sensor is ok and that i should just replace the sensor and it will be back up and running as normal!

[mikeyh]

im in the same situation as yourself,
if your car is an import like mine you`ll haev a long wait for a part number as they have to send an email to mazda direct and get part number from them which takes 4 bloody days.
so if someone on here has the pastr number then pls share save me abit of time.

[mr_maj]

yes mikey its an import cant they match up with the existing sensor?

[mikeyh]

nope i tried to give him number on it,just got the sillent treatment over the phone.
so surely with the amount of imports over here be more sensable to give them the details on cd would it not?
dealers are getting alot worse theses days,no parts kept in stock or stuff like that.

[mr_maj]

Surely the sensor used on the RX-7 will match up to one used on other models as well! Its just a temp sensor after all, nothing special.

I will go to the dealers with the sensor i removed see what they have in stock, if they mess me around il order one from Japan.

Il let you know what happens mikey, if u have no luck as well let me know.

[mikeyh]

well i contacted my dealer about wednesday and ive still no heard back.
i was just going to buy a whole new water temp and fit it to dash but then id still have to use the exsisting sensor so either way in stuffed the now.

[mr_maj]

il let you know what the dealers tell me tommorow