pinging and knock sensor

**trey1010** · 12-11-2007, 08:02 PM

My car pings when at low rpms while ur giving it a lil bit of gas.. My 99 trans am throws the knock sensor code... My question is, can the knock sensor cause my car to ping, or is the pinging causing the knock sensor code?

**0rion** · 12-11-2007, 08:07 PM

I'm a little confused here. It pings at low rpm with a little bit of gas? Sure you don't have an exhaust leak? Are you sure it's knock? Do you have a way to data log it? The knock sensor just "listens" for knock and then pulls timing. What sensor code are you throwing and have you washed the engine with a hose? Water has been known to collect under the intake and kill the knock sensors.

**trey1010** · 12-11-2007, 09:05 PM

ooo ok sorry for the bad description, Like say i am in 5th at a 30 or something very lower and i floor it, that would definately be a time it would ping(sounds like marbles bouncing around) Yes i have washed the engine before... So since it is throwing a knock sensor code, is that telling me the sensor is bad? the code is something like p0332 or near that...

**Vertiviper** · 12-12-2007, 04:51 PM

Originally Posted by trey1010

ooo ok sorry for the bad description, Like say i am in 5th at a 30 or something very lower and i floor it, that would definately be a time it would ping(sounds like marbles bouncing around) Yes i have washed the engine before... So since it is throwing a knock sensor code, is that telling me the sensor is bad? the code is something like p0332 or near that...

In 5th at 30mph??!?!! Good lord downshift!

**trey1010** · 12-12-2007, 05:22 PM

LOL yes i know that would be ridiculous I was just giving an example of when it would happen...

**0rion** · 12-12-2007, 05:34 PM

are you really loading the motor up that much or was that just an extreme example? Also, what grade of gas are you running and what if any mods do you have done?

**trey1010** · 12-13-2007, 01:27 PM

that was an extreme example. I am using 91 octane and it is bone stock.

**0rion** · 12-13-2007, 04:19 PM

it would be nice to datalog it to see just how much knock you're seeing. If you're pulling a bunch of oil into the intake you *may* just have a build up of carbon causing the knock. You can do a search for "catch can" to find the solution to your oil in the intake although it's not a solution to stop the oil use, just to catch it before it gets to the intake. That just comes with the LS1's. An LS6 pcv system is also an option but more work than a catch can.
I would replace those knock sensors since they're relatively cheap and not hard to do. 332 is the rear sensor but if you're already down that far I would probably just replace both.
I would also run some seafoam through it to burn off any carbon build up. You can find seafoam at any parts store.