2008 CX-9 Oil Pressure Switch

The car has an aggressive oil leak only when running behind the alternator. It's a sensor that goes into the block behind the alternator. It has a white-ish plastic wiring connector and it drips oil straight out of the back of it when the engine is warm and running.

I called the dealer and described its location and they said that was the oil pressure switch and ordered me one for a measly $6. It should be here tomorrow.

In my service manuals this switch, in my observed location, is only mentioned once in that location but then described in the service procedures as next to and above the oil filter more towards the transmission, so I just want to see if I can firm this up.

I am pretty sure the leaking sensor is an oil pressure device.

1. Is this the oil pressure switch?
2. It looks easy to get to with an extension and a deep socket. Am I correct?

Thanks!
 
Haven't replaced one myself but the service manual is pretty clear about its inspection and replacement. This image from the manual shows the SST used to measure pressure being attached right where the switch is located. Should be fun to remove/replace.

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Thanks. Yup that's it.

To close the loop I changed mine yesterday. $6 part from the dealer. A little tight, but can be gotten with a short extension and deep socket from behind the radiator fans. Not too bad. Getting the connector off was the hardest part. I used a curved needle nose to push the clip release on the connector and off it came. It's "blind" working mostly using feel from the top. If you are changing the radiator, that's the time to replace this cheap part. Much easier to get at with the radiator out.

And that's what was leaking, through the sensor.
 
Good evening. I had the oil light on, but I realized that when I was driving over bumpi roads, the light went off. So, I replaced today 29Nov2020, the Oil Pressure Sensor Switch.
When replacing Oil Sensor Pressure Switch on Mazda CX9 2008, is not neccessary to drain the oil.
I had that question, so there it is. Yes, it will drain oil when the OSPS is removed, around 237ml of oil. So be prepared.
How I did it:
1. Sprayed some DW40 using a stick with a canal so it can run thru down the connector.
2. Removed connector with left hand. My nails helped me greatly. Over the radiator. Injector cable can be loosen a bit.
3. 21mm ratchet (the extended one), plus 2 small extensions, the big one was too large.
4. I had to put some cooking oil on my arms so my hands were able to go thru. But at the end the tools were oiled and it was a bit difficult to install the new one. I ended using gloves to tighten it up.
5. Applied thread sealant. And went under CX9 to install OSPS, for the first turn, I did the rest from above.
6. Make sure not to loose the rubber gasket from the old one. You will need it.
7. Make sure to leave the part where the connector secures the connection looking upwards. Mine was not all in, so, I installed the same way.
 
Some pictures from the location. That one was the new one. It was not all in so it can be visible.
 

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The car has an aggressive oil leak only when running behind the alternator. It's a sensor that goes into the block behind the alternator. It has a white-ish plastic wiring connector and it drips oil straight out of the back of it when the engine is warm and running.

I called the dealer and described its location and they said that was the oil pressure switch and ordered me one for a measly $6. It should be here tomorrow.

In my service manuals this switch, in my observed location, is only mentioned once in that location but then described in the service procedures as next to and above the oil filter more towards the transmission, so I just want to see if I can firm this up.

I am pretty sure the leaking sensor is an oil pressure device.

1. Is this the oil pressure switch?
2. It looks easy to get to with an extension and a deep socket. Am I correct?

Thanks!
How do I get the clip off I can't figure it out
 
How do I get the clip off I can't figure it out
At first, I used a screwdriver and a flashlight to make sure it was moving. I sprayed some Dw40 and waited around 10 min. Then, I used my nail from the fat finger and pressed it in while pulling it out.
 
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