2002 Chevy Malibu - Knock Sensor Issues

[quote:1d6fad0e44="violet24"]I have a 2002 Chevrolet Malibu, 65,000 miles, purchased used last august. The check engine light has been going off and on for three months, and has been on steady in the last two weeks. When the light is on, the car hesitates when you accelerate in low speeds. I had an engine diagnostics test done which came back with the codes: P0327 Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor) and P0717 Input/Turbine Speed Sensor Circuit No Signal last thursday (two weeks ago).

I replaced the knock sensor in the car last weekend and then reset the battery/computer and it ran great for three days (190 miles, mostly interstate). Today the engine light came back on it started running the same as before. I took it to Auto Zone and it once again has the code P0327 for the knock sensor. They "erased" the code from my car and now it runs better again. I bought a new knock sensor from the store and am hoping that the one I put in last weekend was just a bad one.

Does anyone have any experience with this or could shed some light on this situation? I can't just keep buying knock sensors, so if this one doesn't fix it, what else could I look for? Could something else be causing the knock sensor to have "low input" other than the knock sensor itself? Thanks in advance for any help![/quote:1d6fad0e44]

These KS can get damaged very easily. If they are dropped, they need to be replaced. If the KS is too loose, or over torqued, it may set the code. For intermittent conditions, be sure to check the plug, and harness for any signs of damage, or pushed back pins in the plug. Any pinched, kinked, or swollen wires should be suspect.
Hopefully the KS was bad from stock. There is no way of telling how careful the shipping was for the sensor before it got in your hands.

thank you! i bet that it is a bad one seeing as it was scratched when the guy handed it to me. i will be returning it after i replace it with the brand new one. i might be back if this doesn't work...

Okay, today I had it repaired for $400+. They said that "tech states engine sluggish and detonates under load. Found fuel filter stopped up, plugs look to be original. Tech reccommends minor tune up to stop engine detonating, which is causing knock sensor to set code." Well I had them do the minor tune up which included Tune Electronic Ignition (remove and replace fuel filter) and throttle body and fuel injection cleaning service and new spark plugs.

Does this sound like it could have been the correct cause of the knock sensor code? The car seems to be running fine, but it ran fine for ~150 miles last week before the engine light came back on.

I'm just wondering if I paid all this money for somethign thats not going to fix the problem.

[quote:22b60b9171="violet24"]Okay, today I had it repaired for $400+. They said that "tech states engine sluggish and detonates under load. Found fuel filter stopped up, plugs look to be original. Tech reccommends minor tune up to stop engine detonating, which is causing knock sensor to set code." Well I had them do the minor tune up which included Tune Electronic Ignition (remove and replace fuel filter) and throttle body and fuel injection cleaning service and new spark plugs.

Does this sound like it could have been the correct cause of the knock sensor code? The car seems to be running fine, but it ran fine for ~150 miles last week before the engine light came back on.

I'm just wondering if I paid all this money for somethign thats not going to fix the problem.[/quote:22b60b9171]

Well, are you getting the light on? I find it hard to believe the KS will fault and give a code for needing a tune up. But I guess time will tell. I hope it runs great and you dont get the light again.

no, the light is not on, but i've only driven it 5 miles home from the shop. if you unplug the battery or erase the code it'll go off for a while. you're right, time will tell. they're saying that since the engine was detonating at the wrong time the knock sensor was responding and that made the light come on.

[quote:dac8c0e25e="violet24"]no, the light is not on, but i've only driven it 5 miles home from the shop. if you unplug the battery or erase the code it'll go off for a while. you're right, time will tell. they're saying that since the engine was detonating at the wrong time the knock sensor was responding and that made the light come on.[/quote:dac8c0e25e]

Ok, there is one little line in the trouble shooting that leads me to believe the shop mechanic does know what he is talking about. It states if a mechanical engine kncok can be heard, repair the mechanical condition before continuing. So, with that being said, I would say if your car was actually knocking, it may set the code as you described. So I would feel confident that the money you spent will indeed fix the problem.
Im sorry I didnt suggest that earlier when you described your car as having a loss of power when this happened.

Well, I'm just glad that I didn't pay the original mechanic $250 to replace the knock sensor and then have him tell me he needed to do all this other stuff. Thanks for your help/patience! :)