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View Full Version : Rewiring knock sensor, yay or nay?


turbotalon1g
05-06-2010, 04:53 PM
Anyone have experience with this?

In the never ending quest to get rid of phantom knock, many people look towards rewiring the knock sensor to the ECU. A 16+ year old knock sensor wire can be brittle or cracked, and it might have too much resistance, which can lead to bad knock readings.

Any tuners seen this recommend it?
This peaked my interest as I have always had bad phantom knock issues.

4g63tcrazy
05-06-2010, 04:57 PM
I have rewired my harness for the 5th time now. Last time being this morning when I finished it all up. Between the 2 harness's I have the wires dont seem to be brittle at all. It's just a single 12 gauge (i think) wire, brown with a white stripe. But like I said neither of them semed to be brittle at all.

munchgsx
05-06-2010, 04:58 PM
I would start by checking resistance from the sensor back through the harness. I know there is some kind of formula that uses lenght and gauge the get what it sould be.

Pushit2.0
05-06-2010, 10:42 PM
I would also start with an ohm check, both threw the wire and any shorts to ground. If you were to re-wire it make sure you have a insulated casing that will shield the wire from electrical noise, tin foil wrapped around the wire with electrical tape over that then ground the tin foil on both ends to a clean chassis/engine ground. Also keep the wire as fare away from ignition and CAS and other ground wires as possible.

~John

123abc
05-07-2010, 07:55 AM
I would also start with an ohm check, both threw the wire and any shorts to ground. If you were to re-wire it make sure you have a insulated casing that will shield the wire from electrical noise, tin foil wrapped around the wire with electrical tape over that then ground the tin foil on both ends to a clean chassis/engine ground. Also keep the wire as fare away from ignition and CAS and other ground wires as possible.

~John

This.


We had to re-wire a plug back on the harness of my friend's 92 TSI so we could hook the knock sensor back up. It's been working fine so far, but I don't think re-wiring would solve phantom knock issues or an over-sensitive sensor. I have heard of using plumbers tape on the threads in an attempt to try and cushion the vibrations a bit more, however.

munchgsx
05-07-2010, 07:08 PM
You remember the old how to see if knock is real, Higher octane fuel if it goes away it's real. The car on corn had no knock last night.
200,000 miles=Knock on pump.