[Mx5Xoom]

Well... I pulled the codes from my '5 today. And i got the o2 Sensor (I was expecting that one) But the one that threw me was the "Water Thermistor" (code 9) Does anybody have any idea what this is or where it is located. What are the symptoms of a bad or broken one?

Any help is appreciated.

Thanks
-Jeremy

 

[roadsternut]

Back of the cylinder head, under the CAS on 1.6 cars. Its the sensor with the green connector. Complete git to reach.

My M2-1002 has a bad one at the moment; when warm, it hesitates at about 4500 rpm.

 

[Mx5Xoom]

dammit.... and i thought the o2 sensor would fix the hesitation... its still going in on Thursday just for good measure. Now i gotta go get a thermistor.

 

[Skinnyroadster]

Yay, I am not the only one with the thermistor problem.

 

[Mx5Xoom]

Ok... went to Mazda Idiot Bar... They were shaking their head about the thermistor. They wanna charge 120 bucks to "look" at the car and figure out exactly what the problem. Seems as tho there is no mazda part exactly called a "thermistor". I think im just gonna wait on this one. Ugh... but the hesitation sucks... car has no balls everynow and then.

-Jeremy

 

[roadsternut]

You can get pattern parts cheap.

If you get stuck in the US, you can order the part from:

http://www.ekmpowershop2.com/ekmps/shops/autolinkuk/index.asp?function=DISPLAYPRODUCT&productid=375

1.8 version is slightly cheaper.

Even the genuine part doesn't break the bank:
http://www.mx5parts.co.uk/product_info.php/products_id/862

Take off the coil pack, use wrench to remove the sensor and replace. The connector can get pretty oiled up from a leaking CAS seal, and I think this can give a bad connection, rather than being a sensor per se. So worth checking its all clean first. The connector is held in place by a wire clip, like the AFM, so be careful when unclipping it it doesn't fly offsome place.

 

[Skinnyroadster]

you shouldnt even need to remove the coil. I just used a deep socket , swivel joint thingy and a long extension bar and broke it loose. Once the wires are unclipped the socket slipped over rather nicely.

 

[PYTHON]

i got the same code...i guess i need to replace mine but i am poor right now

 

[Mx5Xoom]

Sooooo... lemme get this straight... that is a temperature sensor for the coolant. Right? The thing that puzzles me is this then. My temp gauge works fine. So are there two different temperature sending units? One for the guage and one for the Ecu to read?? This is confusing. No wonder the people at Mazda looked at me like i was crazy when i was askin for a thermistor.

-Jeremy

 

[michael heinitz]

On the 1.6L, there is a seperate sensor for the gauge.

Also, you may not need a new O2 sensor. You probably got a 'sympathy' code for the O2 because the thermister is dumping in too much fuel. BTDT

-Mike

 

[Mx5Xoom]

thank you soo much mike and roadsternut... that explains it all.

Geez, i love this forum.

Thanks all,
-Jeremy

 

[roadsternut]

you shouldnt even need to remove the coil. I just used a deep socket , swivel joint thingy and a long extension bar and broke it loose. Once the wires are unclipped the socket slipped over rather nicely.

Quite possibly in a LHD car. RHD cars don't have as much room.