2 sensors on 3L

[RodneyBur]

I have two sensors on my 3L block. One on the front side and one on the back side. The one on the front side has a two wire connection, but the 2.5L has a single wire connection and must be switched over. The one on the back also has a two wire connection. I cannot find a connection for the wire harness and was going to cut it but wanted to make sure I didn't need it.


Do I need the back sensor on the block? Can someone tell me what these two sensors are for? I'm thinking temp sensors but not sure. Thanks.

[Blackcoog]

You need to remove all the 3L sensors and use the 2.5L sensors. The one on the front is the oil pressure sensor and the one on the back is the knock sensor. Most cars have knock sensors but some don't. My Cougar never had a knock sensor or the wiring for one but Ford said all Cougars should have knock sensors so I'm a little confused on what happened there. Just put in the correct oil pressure sensor from the 2.5L and then remove the knock sensor if you dont have the connector for it (connector should be green if you do have one for it).

Temp sensor is on the water bypass which you should have swapped over. The 3L one is plastic (the new 3L one is anyway).

[RodneyBur]

I didn't see a connector for the knock sensor. I have a early 99. I double check and just cut the wires on it if I don't have one. Thanks.

[Blackcoog]

I also have an early 99 so maybe it has something to do with that. What do you mean by cut the wires? You shouldn't have a wire for it unless you are using a different wire harness. You would just remove the knock sensor.

[ilovemycar]

Just for additional info...i also have an early 99 and do not have a knock sensor! :rolleyes: .....good job Ford lol.

[RodneyBur]

You shouldn't have a wire for it unless you are using a different wire harness. You would just remove the knock sensor.


I meant cut the wires on the sensor that is in the block and leave the sensor in.

I thought if I pulled it out oil / coolant / or a giant mouse might come out.

[Blackcoog]

You can pull the sensor out. The knock sensor isn't plugging anything it is just screwed into the block and monitors vibrations.

[Topik]

Yeah thats odd. The cougar at school I worked on in EMS class had a knock sensor and it was super early 99.

[doublebacker4l69]

On the issue of the oil pressure sensor...the sensor from my 2.5 has smaller diameter threading than the 3.0 one...I'm not sure what to do :disgust:


EDIT: Scratch that, I didn't see the fitting that the sensor went inside...it was still connected to the 3.0

[RodneyBur]

you got any pics of the setup? I discovered the same problem on my car. I just purchased a 2.5 sensor from ford and when I went to install it I found it was smaller diameter of the 3l sensor.



Ohh. and my cougar has a build date of 98

[Blackcoog]

He already figured it out. The sensor screws into a fitting that has the correct threads on it. You need to pull the fitting out also.

[RodneyBur]

is this "fitting" on the 2.5l block or on the 3l? And if it is on the 2.5 block does anyone have an extra one lying around?

[Blackcoog]

It's on the 2.5L block. I don't think it is on the 3L block.

[doublebacker4l69]

yea, the fitting is on the 2.5...the 3.0's sensor doesn't need a fitting because it's threading is wide enough