KevinD

Is there an easy way to test the knock sensors when off the car? I am buttoning up the 3L and just wanted to ensure these were working before I buried them under the intake. All I have to diagnose with is a cheap multimeter, a paper clip and a pack of gum.

theedge

Best way is to get it all running, then tap the engine block with a hammer (dont tap the knock sensor or its bolt). Try a light tap first, and then tap a bit harder. Eventually youll hear the engine sound change as it pulls timing as it mistakes the hammer taps as "knock".

Van

There is a multimeter check, I believe... I'll see if I can find it.

KevinD

Thanks guys. I'm not too worried about them, I just thought if there was an easy multimeter check that could be done w/o the car running I would do it now and it would be slightly easier to get to them now rather than when the engine is in and running.

Eric_Oz_S2

I am about to replace mine in my 89 S2 as a matter of maintenance. I'm not sure if mine are faulty, but disconnecting them has no impact on performance. I thought the ignition is retarded 6 degrees if there is a fault - but makes no difference. My Hall Sensor is new - so I know that isn't the problem. I am running a Promax chip, so perhaps the chip doesn't take knock into account? I recall that there were some issues with the 91 S2s running Promax chips, but I though the earlier S2 had no problem. Anyone investigated this before or know anything about this issue.