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View Full Version : excessive engine knock- spark noise?



4153dodges
07-22-2014, 05:06 AM
I finally got the pickup running decently, turned out the o2 sensor wasn't working. Hard to diagnose, tunerpro always said it was sitting at 448 MV, even with no sensor hooked up! I could get it to change if I ground the sensor wire, any idea why it does this? Anyway, the real question is about knock counts. I was watching the count, and after a 5 minute run it claimed 31,400 knocks! however, the truck ran perfectly fine and quiet. I didn't hear a single ping, so I knew something was wrong. Then I realized something...
5 minute run, about average of 2000 RPM out of a 6 cylinder engine. That's 3 ignition events per revolution, 6000 per minute, or roughly 30000 in a five minute run. Is it possible that the computer is picking up noise from the ignition system? The sensor wire runs right past the plug wires, and those numbers are way too close. Have you guys ever heard of this?

RobertISaar
07-22-2014, 01:58 PM
The sensor wire runs right past the plug wires, and those numbers are way too close.

that can do it. especially if the wires are run parallel to each other, gives a lot more opportunity for the plug wires to induce current into the knock sensor's wire.

EagleMark
07-22-2014, 05:04 PM
Yes it's possible. But if the knock sensor is bad or disconnected it will just keep counting!