What part is this...?

[BlackLeaf]

Two parts, actually. Have been pulling apart my b6 engine. I can't recall where these came from and what they are...

[rascal]

Looks like an oil pressure sender on the left, found on the upper rhs side of the block, and on the right looks to be a water temperature sender, found at the back of the head

[BlackLeaf]

Righto, thanks.

[StillIC]

The temperature sensor on the right is likely the sensor that sits on top of the thermostat at the front of the engine. The one at the back normally has a green body.

[93_Clubman]

NA6 has two CTS at rear of head, plus the one on top of the thermostat.

[BlackLeaf]

Good info, thanks. Why is the water plug cursed?

[smy0003]

Cursed because it leaks and is a PITA to change. The black CTS sensor is for the temperature gauge on the dash IIRC, the green for the ECU and the one on the front for the thermo fans. Someone will correct me if I'm wrong hopefully. These three were consolidated to one for the NA8

Sent from my LG-H815

[93_Clubman]

The black CTS sensor is for the temperature gauge on the dash IIRC, the green for the ECU and the one on the front for the thermo fans. Someone will correct me if I'm wrong hopefully.
Yep, correct.
These three were consolidated to one for the NA8.
Consolidated to two on 1993 NA8 at least - there's a small CTS below & to the rear of the exhaust headers.

[smy0003]

As in down here?

[93_Clubman]

Yep

[smy0003]

Hmmm no such sensor on my '95 NA8, just two bungs (one for coolant, one for oil). Mazda obviously reduced the number of CTS more gradually than I thought, thanks Clubman.

Sorry for the tangent, BlackLeaf.

Sent from my LG-H815

[93_Clubman]

16 bit ECU replaced 8 bit ECU in Aug 1995 in Japan, although ADM didn't seem to get 16 bit ECU in our NA8 until beginning of 1996. Some years ago I bought an 8 bit ECU from a 12/95 (on compliance plate) NA8 that was written-off & parted out by a forum member in Melb, which was a P4 revision, as opposed to my P3 revision, or the P5 revision of the 16 bit ECU etc.
MX5-1.8-BP-9/93-12/94--JM0NA30P300100001-200000
MX5-1.8-BP-12/94-12/95-JM0NA30P400100001-200000
MX5-1.8-BP-1/96-11/97---JM0NA30P500100001-200000

[smy0003]

Mine was a '95 two plug ECU, so pre-16bit.
Also have had both bungs out so I'm fairly certain there's no CTS down under the extractors on my car.

EDIT:

Looks like it's on the back of the head:


Seems like It's a sensor for the gauge, which would be why Tridon lists 'TTS001 - WATER TEMPERATURE SENDER (GAUGE)'.
Never saw it when I was doing the coolant re-route because it lives under the CAS... not a job I'd ever like to do. I actually put a third VDO CTS in with the reroute so now I have three.

Cheers, Clubman, was unaware of the second sender.

[NitroDann]

As in down here?

This I have never seen or heard of and Ive been down in that area of hundreds of MX5s.

Dann

[BlackLeaf]

I agree. I just checked my engine again and it does not have that squiggly red circle on it.