88 ck 2500 pinging

[shimpies9r]

hello have a 88 2500 with 350 auto 56000 miles took off starter and broke knock sensor put a new knock sensor on pinged real bad checked some places said it had to be torqued to spec if to loose or to tight doesnt read right so i tighted it some more and it went away for the most part but some times it still pings anybody know about this thanks

[maxwedge]

Welcome to AF, check your egr system, also can cause excess pinging.

[tec5120]

the plug that goes into the sensor might of got damaged.run the vehicle and lightly tap on the sensor with a screwdriver handle you should hear the engine making adjustments.if not the wire conn is bad..........

[shimpies9r]

thanks for reply i tapped on block and on sensor when running nothing were do you get new wire harness at or is the a fuse or something inline thanks

[shimpies9r]

bump

[twistedtech]

Tap on the sensor? Uhhhhh ok. Never heard of that one. When you do that does the engine announce that it will be making changes?. I'm willing to bet that a truck with that little amount of miles on it and that age it is prob FULL of carbon. Having your shop scan it while driving will tell you if it is working. It will show up in the data stream.If it is still pinging than you either have not set the timing right or it is full of carbon.

[shimpies9r]

ttt

[webbch]

Tap on the sensor? Uhhhhh ok. Never heard of that one

I can't talk to whether or not this works, but at a conceptual level it passes the sniff test. A knock sensor is just an automotive term for an accelerometer with a specific function, right - probably tuned for high frequency vibration sensing. So if you hit it with a metal object you should easily be able to replicate that high frequency vibe it was designed to detect.

Now as far as how long the sensor has to "knock" before action is taken by the engine computer, I don't know. I'd be curious to know if anyone has tried this technique successfully.