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3L Knock Sensor and 2.5L Knock Sensor

CSVT#49

CSVT#49

Addicted CEG'er
Joined
May 28, 2004
Messages
6,768
Location
Andover, MN
Alright guys I've done some searching and I've seen mixed results. On my 05 Escape 3L I didn't see a knock sensor, or rather I don't remember seeing a knock sensor. I guess that's what happens when you try to think back 3 years. I looked at online auto parts stores and it is of a different design so I'm pretty sure it wouldn't work anyway. In any case on the 2.5L the knock sensor is located on the rear side of the block just in front of the trans. The 05 3L block does not have a threaded hole for the knock sensor at that position. What I could do is thread in an adapter to the smaller hole that is not used in the back, but the knock sensor at that point may not see enough of the surface for a good reading depending on the adapter.

Thoughts?
 
My 06 Escape engine did not have a knock sensor either, what I ended up doing was ordering a new one and splicing the connector for the Escape knock sensor into the 2.5l harness. This way the knock sensor is located where it is meant to on the block. I haven't had a single issue related to the knock sensor.

I have a whole bunch of links saved from when I was researching the swap, I'll run through them and see if I can find some more info about this, I think there was one with the wiring info.
 
I used an 04 block, it had a threaded hole on the back side edge. I drilled and tapped the hole for 2.5 sensor. Have been tempted to splice in the 3l knock sensor. The car feels like it isn't adapting properly with the 2.5 one.
 
you don't really need it. My SE never had one, there is no plug for it on the wiring harness. I am also using an SVT PCM and have never had a CEL for the knock sensor.

otherwise I have heard of people doing both, tap for the 2.5L sensor or splice the 3L sensor. Some have argued that the sensors are unique to the block and to read right they have to match, not sure I believe that ....
 
BrApple said:
you don't really need it. My SE never had one, there is no plug for it on the wiring harness. I am also using an SVT PCM and have never had a CEL for the knock sensor.

otherwise I have heard of people doing both, tap for the 2.5L sensor or splice the 3L sensor. Some have argued that the sensors are unique to the block and to read right they have to match, not sure I believe that ....
Click to expand...

Looking at the sensor it just looks like an accelerometer. They are sold in many different ranges, but for this application I'd imagine they'd be in just about the same range from the 2.5L to the 3L. What it would come down to is the sensor type and sensor output and whether that would be common. As I mentioned before I looked up the 3L knock sensor online and it looks completely different from the 2.5L one so I doubt that they would have the same output signal. I think the people that are not installing them are just getting lucky as there must not be any diagnostics for the knock sensor providing an open circuit then as for the 3L sensor being spliced in... it's possible that it's working range is such that it's not tripping any diagnostics either. I don't know.
 
We've always drilled and tapped our 3L blocks so people can install their stock 2.5L sensor. Then they don't have to splice their harness. We've never encountered an issue doing it this way. If you need a newer 3L knock sensor you can stop out and grab one from us. We'd just toss it anyway.
 
Blackcoog said:
We've always drilled and tapped our 3L blocks so people can install their stock 2.5L sensor. Then they don't have to splice their harness. We've never encountered an issue doing it this way. If you need a newer 3L knock sensor you can stop out and grab one from us. We'd just toss it anyway.
Click to expand...

I'll see where it ends up. I may take you up on that offer. Certainly would be less of a hassle then drilling and tapping.
 
if i remember correctly. on my early 99 cougar. i just spliced it in and it was only 1 wire... if im even thinking about the correct sensor. and im having no issues
 
aboythatskates said:
if i remember correctly. on my early 99 cougar. i just spliced it in and it was only 1 wire... if im even thinking about the correct sensor. and im having no issues
Click to expand...

knock sensor has two wires. you are most likely thinking about the low oil pressure sensor, which is just one wire.

also it has been determined before the most if not all non-svt 99's do not have a knock sensor.
 
Havnt had a knock sensor in my last two 3Ls. I'm not saying you did the same. Just letting you know that not having one causes no problem. Besides, on the monster u're building, by the time ur knock sensor is tripped, it'll be too late then.
 
It's my understanding that the knock sensor does not have any diagnostics associated with it. Thus no CELs if its unplugged or otherwise. Simply pulls a boatload of timing if its dectecting knock. When Warmonger tuned my 3L-T he ended up tunring it off. It was picking up knock under light conditions where there would/should be none. Pretty much un-tunable until he turned it off. Mixed tuning session too, dyno and road tuning.
 
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