Pinging - knock sensor related
06-22-2013, 04:27 PM
#1
Pinging - knock sensor related I did search on this and got a lot of mixed info. Car pings in the upper rpm range at full throttle. Runs/Drives great normally. Its an 02 WS6, stock except for a pulley a lid. I barely drove it after purchasing it late last year and quite likely never really opened it up. Doubt my 2 new mods are the culprits... Been doing this for a while, so today i let the tank run down and went to different gas station and filled it with 93. Def cut down on the ping but its still there. Are my knock sensors bad? Shouldnt they be yanking timing to stop this once it happens? They do not seem to be. How do i tell? Also, what are other common culprits? Again, this car has never been F'd with, it seems odd. Just hit 32K miles. It hasnt even gotten hot out yet!! Dont imagine its going to get better when it does obviously.
06-23-2013, 10:22 AM
#3
This seems to be a common problem. I went thru the same thing with my ss and believe me I tried everything including the knock sensors. Finally the last thing I replaced totally cured the ping. I replaced the MAF sensor with a oem ac delco unit and the ping is completely gone. You can try cleaning the MAF but it didn't work for me. And if you do decide to replace the knock sensors make sure you use ac delco. Otherwise you will be doing them again. Ask me how I know
06-24-2013, 07:07 AM
#4
This seems to be a common problem. I went thru the same thing with my ss and believe me I tried everything including the knock sensors. Finally the last thing I replaced totally cured the ping. I replaced the MAF sensor with a oem ac delco unit and the ping is completely gone. You can try cleaning the MAF but it didn't work for me. And if you do decide to replace the knock sensors make sure you use ac delco. Otherwise you will be doing them again. Ask me how I know
06-24-2013, 07:40 AM
#5
For what it is worth, I have had daily drivers that would develop pinging following extended periods of stop and go driving. The pinging would go away with some spirited, high rpm operation and/or highway driving. The condition was probably caused by carbon buildup.
06-24-2013, 07:46 AM
#6
Oh, and about the knock sensors - how do I know if they are working? The ping has been pretty bad for several seconds at a time and the computer doesnt seem to be doing anything about it.
Last edited by AnotherWs6; 06-24-2013 at 07:51 AM.
06-24-2013, 08:04 AM
#7
Certainly not an impossibility. However with computers, MAF, O2 sensors etc..... I would think that this shouldnt really be an issue anymore. My 5.0 never had an issues and it had more boltons and aggressively advanced timing. I know the cars are different though, who knows.
Oh, and about the knock sensors - how do I know if they are working? The ping has been pretty bad for several seconds at a time and the computer doesnt seem to be doing anything about it.
Oh, and about the knock sensors - how do I know if they are working? The ping has been pretty bad for several seconds at a time and the computer doesnt seem to be doing anything about it.
If your car has the SLP MAF on it, take it off and install a GM unit. The SLP sensor leans the car out. If your knocks were not working you would have a code. So it may be that the PCM is pulling the max amount of timing it can. Two things can cause knock, too much timing and not enough fuel. I would say you are going lean. The reason why you need to change your MAF. Unless the car has been tuned in the past I would say this is your problem
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06-24-2013, 08:20 AM
#8
A defective knock sensor should throw a code indicating the absence of a low voltage signal.
The ability of the system to detect a knock condition is not foolproof because the parameters of a knock condition are dynamic rather than static. Specifically, the PCM "learns" the typical level of variance it receives from the knock sensors, and therefore, ignores signals below a certain threshold. So it is entirely possible for a working knock sensor to coexist with some level of knock, or pinging.
The ability of the system to detect a knock condition is not foolproof because the parameters of a knock condition are dynamic rather than static. Specifically, the PCM "learns" the typical level of variance it receives from the knock sensors, and therefore, ignores signals below a certain threshold. So it is entirely possible for a working knock sensor to coexist with some level of knock, or pinging.
06-24-2013, 08:52 AM
#9
Thanks guys. OK, so im 99% sure the knock sensors working. If they are pulling max timing and its still knocking then that is pretty scary. MAF is stock. Only mods are slp lid and 25% UDP. So either my MAF is having issues or im not getting enough fuel pressure, which might indicate an ailing fuel pump. Or maybe the I just got a couple of tanks of really **** gas. if it turns out to be nothing more than that I am going back to that gas station like this
06-24-2013, 09:50 AM
#11
A defective knock sensor should throw a code indicating the absence of a low voltage signal.
The ability of the system to detect a knock condition is not foolproof because the parameters of a knock condition are dynamic rather than static. Specifically, the PCM "learns" the typical level of variance it receives from the knock sensors, and therefore, ignores signals below a certain threshold. So it is entirely possible for a working knock sensor to coexist with some level of knock, or pinging.
The ability of the system to detect a knock condition is not foolproof because the parameters of a knock condition are dynamic rather than static. Specifically, the PCM "learns" the typical level of variance it receives from the knock sensors, and therefore, ignores signals below a certain threshold. So it is entirely possible for a working knock sensor to coexist with some level of knock, or pinging.
06-24-2013, 10:26 AM
#12
If the knock sensors were not working you would presumably throw an error code (DTC) of P0327 for knock sensor 1 (see attached) or P0332 for knock sensor 2. If you look at the troubleshooting chart steps 3 & 4, there are some test that can be run with a digital multi-meter on the knock sensor circuitry.
06-24-2013, 02:15 PM
#13
Well do the free stuff. Check fuel pressure key on, and then running.
2nd... pull off the vac line that connects the pcv valve to the intake manifold. I bet there is a ton of oil in it. Before a catch can I use to never beat on my h/c car. The longer I didn't, oil would build up, and it would ping. After a can and and wot once per gas tank, I don't get anything. At the time I was putting 200 miles on my car a week though.
2nd... pull off the vac line that connects the pcv valve to the intake manifold. I bet there is a ton of oil in it. Before a catch can I use to never beat on my h/c car. The longer I didn't, oil would build up, and it would ping. After a can and and wot once per gas tank, I don't get anything. At the time I was putting 200 miles on my car a week though.
06-24-2013, 07:36 PM
#14
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It needs to be recalibrared/tuned.
2002 manufacture had the ECMs calibrated for the fuel at that time,the fuel was ALOT different then it is now.
Then fuel has 10+% ethanol in it now.
Hence the bigger injectors on the newer cars,needs more fuel to make it burn,not more timing.
2002 manufacture had the ECMs calibrated for the fuel at that time,the fuel was ALOT different then it is now.
Then fuel has 10+% ethanol in it now.
Hence the bigger injectors on the newer cars,needs more fuel to make it burn,not more timing.
06-25-2013, 07:08 AM
#15
It needs to be recalibrared/tuned.
2002 manufacture had the ECMs calibrated for the fuel at that time,the fuel was ALOT different then it is now.
Then fuel has 10+% ethanol in it now.
Hence the bigger injectors on the newer cars,needs more fuel to make it burn,not more timing.
2002 manufacture had the ECMs calibrated for the fuel at that time,the fuel was ALOT different then it is now.
Then fuel has 10+% ethanol in it now.
Hence the bigger injectors on the newer cars,needs more fuel to make it burn,not more timing.
What would a tune do on a stock car powerwise? Increase, decrease? Decrease because lean is mean or increase because more fuel is being burned? Of course a decrease would still be preferred over a melted piston.
06-25-2013, 12:57 PM
#16
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from what i have gathered its typical for stock ls1's to be lean from the factory, my bone stock 98 ss is seriously lean and its bone stock
i also read a post where someone was spraying a wet shot and ran out of nitrous (spraying fuel only) and the car responded with the additional fuel = it was lean
let me know what you conclude as im interested myself, i have yet to get anyone to come out and say my bone stock untuned ls1 AFR was xxxx
i also read a post where someone was spraying a wet shot and ran out of nitrous (spraying fuel only) and the car responded with the additional fuel = it was lean
let me know what you conclude as im interested myself, i have yet to get anyone to come out and say my bone stock untuned ls1 AFR was xxxx
07-02-2013, 06:43 PM
#17
A defective knock sensor should throw a code indicating the absence of a low voltage signal.
The ability of the system to detect a knock condition is not foolproof because the parameters of a knock condition are dynamic rather than static. Specifically, the PCM "learns" the typical level of variance it receives from the knock sensors, and therefore, ignores signals below a certain threshold. So it is entirely possible for a working knock sensor to coexist with some level of knock, or pinging.
The ability of the system to detect a knock condition is not foolproof because the parameters of a knock condition are dynamic rather than static. Specifically, the PCM "learns" the typical level of variance it receives from the knock sensors, and therefore, ignores signals below a certain threshold. So it is entirely possible for a working knock sensor to coexist with some level of knock, or pinging.
07-02-2013, 06:48 PM
#18
Well do the free stuff. Check fuel pressure key on, and then running.
2nd... pull off the vac line that connects the pcv valve to the intake manifold. I bet there is a ton of oil in it. Before a catch can I use to never beat on my h/c car. The longer I didn't, oil would build up, and it would ping. After a can and and wot once per gas tank, I don't get anything. At the time I was putting 200 miles on my car a week though.
2nd... pull off the vac line that connects the pcv valve to the intake manifold. I bet there is a ton of oil in it. Before a catch can I use to never beat on my h/c car. The longer I didn't, oil would build up, and it would ping. After a can and and wot once per gas tank, I don't get anything. At the time I was putting 200 miles on my car a week though.
07-02-2013, 07:20 PM
#20
Would disconnecting the battery reset the computer? Would that help the computer "relearn" things? The car sat for six months and the battery died several times. when I needed to move it I would throw it on a trickle charger until it would start. I replaced the battery this spring, but the old one def got the car back from the dead during freezing temps a few times after conking out. Is the computer just all confused now?
Last edited by Darkman; 07-02-2013 at 07:28 PM.