name that sensor

[OB1]

I'M In the middle of a 3l build up & having all kinds of problems that were not found during my research. I have a sensor in my donor svt motor that will not screw into the block of the 3L. here is a pic of the 2.5 sensor, BTW its in the rear just below the head right by the trans.


Now here is a pic of the 3.0 w/ what looks like just a ground screwed into the block.


It looks like I can just find a reducer but I was still wondering what it actually is. Thanks for any help & I'll try to get a better pic posted. Just in case you are wondering the 3L is upside down & the 2.5 is not.

[5speed3.0SE®]

that's the knock sensor. the hole needs to be retapped on the 3L block to fit the 2.5 knock sensor. you can search to find the actual specs for the tap...

[stilov]

I remember one search I did came up with the wrong tap info....just double check to make sure the thread matches the sensor before you tap it.

[OB1]

thanks guys I searched knock sensor & came up w/ some good info, although no pics. It is also being said that you can just splice in the wires & use the new style sensor, but as you can see my junkyard engine doesn't have much to splice to. Looks like i'll check the tool box for a m12 x 1.5 tap, hope thats the right size, or I'll have to buy a new new style sensor. my luck sucks! I can't believe that I haven't seen any of this before during all of my studies!

[warmonger]

that's the knock sensor. the hole needs to be retapped on the 3L block to fit the 2.5 knock sensor. you can search to find the actual specs for the tap...

No, this should not be the case anymore.

You should use the sensor that comes with the block. If that means you cut the plug off the 3L harness and splice it onto your 2.5L then so be it.

The reason is that the sensors are updated and they are somewhat mated to the block. They are tested to detect knock in that block with THAT moving mass.

[stilov]

I thought the sensors were done in correlation with the computer...

[TRicker]

building this 2.5 is gonna be sooo much easier! haha. yeah anyways....i keep hearing that splicing the wires is the best way.....

[Buckshot77]

I've got a couple of those knock sensors with plenty of splicing length left on it. PM me and we can set something up.

Rick

[warmonger]

I thought the sensors were done in correlation with the computer...

Both are correct.

The sensor is installed on the engine and after subjecting the engine to things that generate "knock" or the precursors of knock, the output of that record would be recorded. After enough tests an average from that type of sensor in that type of engine would be input to the pcm code.

So I'm not saying it wouldn't work, I'm saying it probably is no longer as accurate and it could be either more or less sensitive if installed in a different block. I'm sure any knock sensor could be used in any block AFTER it has been tested to see what signals come out from each knock/pre-knock event, but who has the ability around here to do that?
From the reading I've done you would stick the same sensor in the same block and if you were really good you'd take the knock sensor data from the stock pcm code that came with the engine.....but we are only mortal men after all.

I've also found that the old style sensor are way more sensitive and are constantly pulling timing when used on the 3L blocks.

[OB1]

I've got a couple of those knock sensors with plenty of splicing length left on it. PM me and we can set something up.

Rick

Well it looks like I should havebeen patient! I looked around & I had a m12 X 1.5 tap & drill so I priced a new sensor (new style) since my wires were cut, It was around $70 bucks so I went the cheap route. I should be ready to install this thing & I hope it works out w/ the old style. I also factored in the fact that I have 3 of the old style ones laying around.
quick pic!