kapolani

iTrader: (6)

Anyone have a decent write up on how to change a knock sensor on a 2005 Evo VIII?

Pictures would help.

I'm getting some random knock occurrances so I'm going to change out the knock sensor and see if that is the problem.

Thanks!

C6C6CH3vo

iTrader: (9)

The best way to access is from underneath looking up and fwd with feet pointed fwd.

You may need a beer and a straw from this position

justchil

iTrader: (44)

More diagrams for ya...

AutoXer

iTrader: (1)

Is there a way to access the sensor without removing either the engine, tranny or intake manifold? If I remove the 3-bolt tie-bar from the bottom of the car, I can get my hand on it and feel it. However, I don't see a way that I can get a wrench on it. It's in a very tight position.

If not, this needs to be put on a list of things to check when you're doing a clutch job. At a minimum, visual inspection and torque check.

wevo1985

iTrader: (10)

if your getting excessive knock i wouldnt count on it to be the sensor. they rarly go bad. i would check for something that might be tapping like a pipe hitting another 1st. maybe boost to high also. when are you getting the knock the most?

AutoXer

iTrader: (1)

No offense, but you're off topic.

hotrod2448

You should be able to get to it without dismantling much. They changed mine at the dealership pretty easily when they were troubleshooting my mystery misfire. It ended up being the trans making a noise the knock sensor was picking up.

Can you get in there with a crow's foot or something similar?

Also no offense but, his post wasn't really off topic. He was trying to help prevent someone from changing a sensor that does rarely go bad. No point in investing the time unless you are pretty sure it's the problem.

ultimatesteve

iTrader: (8)

Off topic or not hes just trying to help the guy out.

I agree, I would look at other potential issues before messing with the sensor. I had a phantom knock issue and it actually ended up being a motor mount problem.

AutoXer

iTrader: (1)

Part of the problem with forums, IMO, is the ability to find facts and good information. This thread should be about the knock sensor location, how to get access to it, torque specs, wrench size, installation notes, price for a new sensor, etc. This isn't a troubleshooting thread. I appreciate the fact that people are trying to help, but when I need help, I ask for it.

If I wanted help tracking down a source of knock, I'd likely post something like this:
https://www.evolutionm.net/forums/sh...d.php?t=269601
https://www.evolutionm.net/forums/sh...d.php?t=255023
https://www.evolutionm.net/forums/sh...d.php?t=226547

...devils advocate... I just realized that the OP did mention knock. So, I guess it is relative. Maybe I should start a thread of my own on just the sensor itself. [open mouth -> insert foot]

That being said....

What's a crows foot?

mdsevo06

iTrader: (41)

I ended up making my own tool, like the MD998773 shown above. This tool can not be found at any dealer and was told it was a Snap-on, but hard to find. I notched a 27mm deep socket, 4mm by 1-1/2" long, 1/2" socket drive. I'll verify the 27mm size when I go home for lunch, can't remember if it was 26mm, 27mm or 28mm. You'll also need a 3" to 4" extension to reach thru the Mani. Brace. Best way to reach it, by hand was to remove the Strut Tower, reach down the passenger side of the mani. and you should be able to finger tight or loosen. When using the tool, remove the Tie Bar (front) and you can slide the Deep Socket from underneath the car, with your feet pointing towards the front of the car.
When I did this job, I was getting a "Knock Sensor Failure" code and was getting false knock when tuning. When I reached down to grab the sensor, it was loose, I could remove it with out using the tool. Nothing was ever touched back there and was this way from the factory. After replacing the sensor with a new one, the false knock was gone.
Hope this helps, and I will verify the socket size by days end.
Edit: 27mm Deep Socket is the correct size.

sdfontanini

how easy is it to replace?

fugiwara

iTrader: (124)

ttt

TommiM

iTrader: (19)

replacing the knock sensor from on top should take less than an hour. It takes me 20-30 min now. I just remove the 4 bolts holding the bracket to the intake manifold, slide it out of the way, and get my special socket I bought on amazon. dont even need to remove the strut tower bar either.
The socket was like $8. cheap price. search Amazon, they are on there.