SE IAT thread size

[Roadrunner]

Does anyone know the thread size/pitch of the stock SE air temp sensor? The one screwed into the throttle body elbow.

[Lokiel]

Sorry, can't find that info ANYWHERE (not even reference in the service manual, other than the torque specs and calibration curve) and my OEM 90* hose is long gone.

I have a parts diagram that lists every part wit part number (I thought) on an NB and T/C NB but it's missing this information.

Why did you want to use it anyway?
The sensor is enclosed so is slower to react than the commonly used GM sensor (which allows air to flow over the thermistor).

[greenMachine]

I should have the pipe in a box with the other parts I replaced when the Skunk2 TB went on. I'll have a look tomorrow. I am not sure whether the IAT on the car is the stock sensor, or I could pull it out but that might lead you astray.

[Lokiel]

FINALLY found it, see https://partsouq.com/en/catalog/genuine/unit?c=Mazda&ssd=%24HAxLcgEFB0xAUVUFCjkDAAUEc01XWQ8AOXEBSlxeVVh2XVBMC01SR3JGSmkrNjxVAA1ZH3FcWABE%24&vid=1406515898&cid=&uid=19206
... 18-845 (in top left corner box)

Here's the part: https://partsouq.com/en/search/search?q=F2G8-18-845A&qty=1

Still can't find its bloody thread size/pitch though

[Roadrunner]

I want to replace the sensor with an open element one that will thread straight into my FM metal elbow. Seems even FM don’t know what the thread pitch of the nut used on their own elbow is

Im pretty sure it’s m10 but it’s a finer thread than my 1.5 bolts, maybe 1.25 or 1?

[Lokiel]

I don't think FM have their elbow in stock anymore, it's mentioned on other forums.

If you have one, why not take it to a hardware store and try a few metric bolts in there?

[bruce]

I was actually going to suggest Bunnings! Take your elbow there and try the thread checking board in the Fasteners section.

[Nevyn72]

Isn't it an NPT tapered thread?

[greenMachine]

Isn't it an NPT tapered thread?

If the part linked by Lokiel is correct, and the photos are of that part - no, it doesn't look like it (enlarge the photos to see better). In which case, 10mm? That is pretty shaky though.

I have the rubber elbow off the SE, but not the bung which the sensor screws into - must be somewhere down there, but it isn't where it is supposed to be.

[Roadrunner]

Yeah definitely isn’t npt or tapered. Can’t get to Bunnings for a while, plus it’s over an hour round trip not including getting in and out of the place without buying stuff I don’t need .
I found some thread taps in the shed and it definitely isn’t 10mm either. They start but half a turn in bind up. Measuring with some calipers it’s ever so slightly smaller than 10mm. It might just be 3/8th inch??
Maybe I’ll have to see if the wife wants to check out the Bunnings garden centre in a couple of weekends time and sneak off to the thread checker.

[greenMachine]

Most mechanics, and probably the Repco/et al stores would have thread gauges, if that helps ...

[Lokiel]

Don't forget that M10 bolts come in 3x thread sizes, 1mm (fine), 1.25mm and 1.5mm (coarse).

I strongly doubt that it's a non-metric thread too given that it's a Japanese car - the only non-metric stuff on our cars are aftermarket products built in the US

Tapered threads tend to be used for fluids so you can rule that out.

This site, https://www.123spareparts.co.uk/oem-number/n3a118845, has all its Mazda 18-845 intake air temperature sensors with Thread Size:M10x1.25 so I think you can assume this

I assume that 18-845 is the common ID for the thermistor used in WXYZ-18-845 IATs

[Lokiel]

Most mechanics, and probably the Repco/et al stores would have thread gauges, if that helps ...

I've got this after years of getting annoyed about not knowing what size a nut/bolt was if I didn't have another already on hand to test it against:


These would be great too but I'd be annoyed if they got harder to read when the paint rubs off (I HATE that on my impact sockets, the indented text alone is almost unreadable without a torch):


... add a couple of spare 10mm sockets and the bottom one would make a great Xmas gift for the DIYer!

[bruce]

I do like those checkers. But then it leads to the question, do I have an appropriate fastener in the shed (as I dig through my bucket of bolts)?!

[Roadrunner]

Finally made it to the shops: It’s M10x1.25