Barwick

Got a problem, the stock water temp sensor (right by the oil pressure sender "bell") on my car broke off its connector, and I can't connect it anymore, so the stock water temp gauge doesn't work.

But it seems like there's another water temp connector somewhere, because it runs ok when cold and then slows down the idle when warm.

So basically, can I just ditch the stock sending unit (the one by the oil pressure sender "bell") and put in an aftermarket one there, without any problems?

And on that topic, I need to find one that has the *same* threads as the stock hole, anyone know of one that does?

Also, could I just take the stock sending unit and hook it up to an autometer gauge, and it should display just fine?

ViperDude152

You can easily buy a new temp sending unit from mazdatrix.com and just replace it easily. It will screw right into its place.

ilike2eatricers

I believe the water temp sensor near the oil pressure sensor only affects the function of the gauge. I believe the waterthermo sensor behind the waterpump is the one we really need since it sends a signal to the ECU. Does anybody know the threads for the water temp sensor? I'm sure you could get an adapter to fit the sender from your aftermarket gauge on there, but fitment in that area will be kinda tight.

Barwick

I fitted an adapter on a 12A race car before, but it involved a couple of adapters, some miscellaneous parts, and some drilling/tapping... it really was a ghetto job, but it worked.

Is it possible to just splice a gauge into the stock one behind the water pump?

NZConvertible

You should avoid using adaptors to fit temp senders if at all possible. Temp senders are most accurate when they're fully immersed in the water flow, but adaptors almost always space the sensor further back, reducing the sensor's exposure to flowing water.

If you want to keep the stock temp gauge functional then simply buy a replacement sensor. If you want to use an aftermarket temp gauge (which will almost certainly have a sensor bigger than stock), then you should drill and tap a hole in the water pump housing.

Barwick

I don't want to screw with that thing, it can cause nothing but issues...

but if I were to do that... which part of the water pump housing do you drill into? (I'd imagine you have to remove it and drill/tap it off the vehicle, correct?)

And finally, why wouldn't a stock sending unit work with a gauge? I've heard from multiple people that sending units are sending units, almost always the same thing, just different threads.

NZConvertible

Why would it? Water pump R&R isn't particularly difficult.

Next to the ECU's thermosensor on the back. You can't to this with the pump on the engine.

They're wrong. The gauge must be calibrated to the sender and it's highly unlikely two different senders will give you the same reading. If they did aftermarket gauges wouldn't need to come with their own senders.

Barwick

craaaaap

Ok, we *really* need to find a gauge company that sells sending units with the same threads as the stock one.