What you put in, you'll get back ten fold

Replacing the temp sensor on the MK 2/2.5 ( For Andrey)

User avatar
Mazda Mender
Site Admin
Posts: 12971
Joined: Tue Dec 06, 2011 6:18 pm
Location: Pie land,North west

Replacing the temp sensor on the MK 2/2.5 ( For Andrey)

Postby Mazda Mender » Mon Jul 09, 2018 10:18 am

This is a easy enough sensor to change on a NB which picks up the water temp and tells the ECU which then uses it for a few other items on your roadster, one being for the cooling fan to kick in and off to stop overheating, it can become intermittent or just fail, stopping the fan from working which can give a major issue of overheating that these little roadsters hate with having a alloy head to warp ...

This can be done with the basic of tools on a NB and can be done without removing the coil pack which is a bit fiddly ,but a lot easier if it is just pushed out of the way...sometimes more is less..


So you will need
1 x 19 mm deep 1/2 " drive socket
1 x 1/2 drive extension piece
1 x 1/2 drive Ratchet
****** or ********
1 x 19 mm spanner( open end )
New sensor with sealing washer....
1 x 12 mm ring spanner ( long )
***** or *****
1 x 12 mm 1/4 drive socket
1 x 1/4 Drive Ratchet

And that's it, although I was working on the engine with far deeper servicing etc this guide was built from but there is no need to remove them but recommended...

Crack and remove the 12 mm bolt at the bottom of the coil pack at the back of the engine and remove it with a ring spanner not flat open, there is no need to to put this back..( keep young kids away at this point as there will be a lot of swearing 100%....)
Crack the two 12 mm bolts that hold the coil pack to the rocker cover and remove, put them safe..

20180706_150331.jpg (460.46 KiB) Viewed 269 times

20180706_150552.jpg (552.32 KiB) Viewed 269 times

20180706_150439.jpg (572.16 KiB) Viewed 269 times

**** or 1/4 Drive Ratchet with a 12 mm socket *****

20180706_150820.jpg (536.28 KiB) Viewed 269 times

20180706_150409.jpg (643.04 KiB) Viewed 269 times

Pull the HT leads free from the spark plugs and wells...

20180706_150938.jpg (590.29 KiB) Viewed 269 times

20180706_150836.jpg (618.52 KiB) Viewed 269 times

Put the HT leads out of the way and push the coil pack out of the way ( there is no need to disconnect the power plugs)

20180706_150132.jpg (527.86 KiB) Viewed 269 times

Working from the passenger side.....

So now you should be able to see the temp sensor,(triangle shape) at the back of the engine under the coil packs coming from the passenger side...
Unplug the plug with 3 x wires coming from it

20180706_150200.jpg (474.1 KiB) Viewed 269 times

Once unplugged get your deep 19 mm socket or spanner ( if using a spanner careful not to round the sensor off with being to ham fisted) and crack the sensor loose, once loose unscrew it out, making sure the old seal washer is removed and it is a simple case of the new seal washer and sensor , screw it into place and nip it up tight with the deep 19 mm socket or spanner, plug the plug back into the new sensor and listen for the click that means the plug has gone all the way home.
And that's it, bolt the coil pack back up, push the HT leads back to where they should be and job done on a NB, start her up and see if it has cured the issue....there is a lot more to be removed on a NA for this to be done ( shout if you need a guide)

20180706_150200.jpg (474.1 KiB) Viewed 269 times

20180706_150205.jpg (464.86 KiB) Viewed 269 times

20180706_150137.jpg (600.29 KiB) Viewed 269 times

20180706_150132.jpg (527.86 KiB) Viewed 269 times

20180706_150145.jpg (546.47 KiB) Viewed 269 times

AS always any questions, just ask , it's what we are here for....
The Disclaimer:-
This post is a natural product made from recycled electrons. The slight variations in spelling and grammar enhance its individual character and beauty and in no way are to be considered flaws or defects, the articles/answers/comments are provided for information purposes and they are not intended to substitute informed professional advice, I or mazdamenders.net cannot personally be hold responsible for any damage occurred from following this procedure or any injuries from it. Proceed at your own risk.

Mk 1 Eunos 93 black V.S II 1.8 ,
Mk 2 .1/4 Roadster 99 black & gold V.S 1.8 being rebuilt,
Mk 1 Eunos 90 1.6 (claimed by daughter)
MK 2.1/4 Blue V.S Roadster 1.8 99 ...being rebuilt
Mk 1 Eunos 95 blue G-ltd 1.8...being refurbed
http://www.mx5oc.co.uk/ http://www.mx5nutz.com/forum/ http://miata.net/ http://www.autolinkuk.co.uk/

Return to “Electrics”

Who is online

Users browsing this forum: No registered users and 1 guest