Pinging"...
Thread Starter
Team Owner
Joined: May 2001
Posts: 87,294
Likes: 1,579
From: Western NY
Pinging"...
OK, I'm an "old timer", I'll admit, and remember in the "old days" if you advanced the ignition timing too much, the car would "ping" under load, or if you were really gettin' on it. A lot of that has gone away, thanks to the current state of computerized ignition control.
I'll also admit that my car sees a lot more "cruising" that some of my former "muscle machines", due mostly to the increased volume/density of traffic in my area. Nonetheless, I hit an clear, traffic free "on ramp" to the expressway earlier today, so I thought I'd enjoy a little run through the gears.
I got up around 5-5500 RPM in first, and by golly, I swear the car was "pinging". I quickly grabbed 2nd, again revved it up around 5000 RPM, and the same thing happened. I eased up through 3rd to 6th, and nothing sounded wrong, and the car runs OK. I haven't had time to check for any codes, and I'm gobbling down lunch as I type, before running some errands, so I can't check right at this moment.
This is a "first" for this car. Anybody else have this happen? Is it a sign of something broken?
I'll also admit that my car sees a lot more "cruising" that some of my former "muscle machines", due mostly to the increased volume/density of traffic in my area. Nonetheless, I hit an clear, traffic free "on ramp" to the expressway earlier today, so I thought I'd enjoy a little run through the gears.
I got up around 5-5500 RPM in first, and by golly, I swear the car was "pinging". I quickly grabbed 2nd, again revved it up around 5000 RPM, and the same thing happened. I eased up through 3rd to 6th, and nothing sounded wrong, and the car runs OK. I haven't had time to check for any codes, and I'm gobbling down lunch as I type, before running some errands, so I can't check right at this moment.
This is a "first" for this car. Anybody else have this happen? Is it a sign of something broken?
Instructor
Joined: Nov 2008
Posts: 227
Likes: 4
From: Austin Texas
Pinging
Most likely it's due to gas or carbon build up. If your motor hears any " knock " it will pull the timing. Considering that most of your driving is in traffic and it does'nt get a chance to stretch it legs know and then can be a problem I guess. If the problem continues get it checked out. Never had a problem in the car, but my truck did it off and on. GM had a product awhile back called "top engine cleaner" that was great for removing carbon. I've used it before on the truck and haven't had any issues since.
Thread Starter
Team Owner
Joined: May 2001
Posts: 87,294
Likes: 1,579
From: Western NY
Most likely it's due to gas or carbon build up. If your motor hears any " knock " it will pull the timing. Considering that most of your driving is in traffic and it doesn't get a chance to stretch it legs now and then can be a problem I guess. If the problem continues get it checked out. Never had a problem in the car, but my truck did it off and on. GM had a product awhile back called "top engine cleaner" that was great for removing carbon. I've used it before on the truck and haven't had any issues since.
Instructor
Joined: Nov 2008
Posts: 227
Likes: 4
From: Austin Texas
Top Engine Cleaner
I stocked up on it awhile back. Heard that it wasn't going to be available much longer. I bought the bottles and the aerosol cans that they had left. It does make your vehicle smoke! 
Burning Brakes
Joined: May 2011
Posts: 1,216
Likes: 56
From: Houston Texas
My '99 use to do the same thing when it was stock. It was somewhat aggrivating that it would since typically a factory tune is conisdered to be overly safe. Ever since the mods, and my re-tune with HP Tuners, there hasn't been any audible knock or by sensor.. 
Now, of course the pcm has safety features to pull up to a designated maximum amount of timing based on knock detection... but there is a catch.. engine knock, or detonation, suffers from hysteresis
. Therefore, once you are already to audible knock it takes more of a timing reduction to eliminate it than where it first began. This is because of the in cylinder temperature staying higher than normal from the detonation event.
Anyway, back from the tangent... hopefully the top-end cleaning helps out. You might consider changing the fuel filter in case of any obstructions present as well. Other than that, I would say to be conscious of coolant/oil temperatures being at their peak for a hot day combined with warm air and any possible high humidity... all of which is a bad combination for knock margin.
Now, of course the pcm has safety features to pull up to a designated maximum amount of timing based on knock detection... but there is a catch.. engine knock, or detonation, suffers from hysteresis
. Therefore, once you are already to audible knock it takes more of a timing reduction to eliminate it than where it first began. This is because of the in cylinder temperature staying higher than normal from the detonation event. Anyway, back from the tangent... hopefully the top-end cleaning helps out. You might consider changing the fuel filter in case of any obstructions present as well. Other than that, I would say to be conscious of coolant/oil temperatures being at their peak for a hot day combined with warm air and any possible high humidity... all of which is a bad combination for knock margin.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 326
From: CA.
St. Jude Donor '13-'14-'15
If the knock sensors are working prperly you should never hear any pinging on a stockish car as the knock sensors should take it all out---Some of the early 97-99's had some bad sensors that failed and wouldn't pick up the pinging---Carbon built-up can be aproblem with a car with many miles or has been sitting for a long time and cause pinging--Also i would suspect a bad tank of fuel---maybe fill it up at a differnt gas station (or did you fill it last time at an older station that might have dirty filters or old gas ??)
I would do check this out 1st---
The knock sensors will send data to your ECM and count "occurances of knock") if it pings alot it will reach some majic # of occurances and your spark table will move to the "low octane" spark table--and it has about 1/2 the amount of timing and run like crap-the pinging should disappear aloong with your power---To reset your ECM back to the "hi-octane " table just fill your tank with at least 10 gallons of fresh fuel and it will rest back to the high table--
I would do check this out 1st---
The knock sensors will send data to your ECM and count "occurances of knock") if it pings alot it will reach some majic # of occurances and your spark table will move to the "low octane" spark table--and it has about 1/2 the amount of timing and run like crap-the pinging should disappear aloong with your power---To reset your ECM back to the "hi-octane " table just fill your tank with at least 10 gallons of fresh fuel and it will rest back to the high table--
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Thread Starter
Team Owner
Joined: May 2001
Posts: 87,294
Likes: 1,579
From: Western NY
If the knock sensors are working prperly you should never hear any pinging on a stockish car as the knock sensors should take it all out---Some of the early 97-99's had some bad sensors that failed and wouldn't pick up the pinging---Carbon built-up can be aproblem with a car with many miles or has been sitting for a long time and cause pinging--Also i would suspect a bad tank of fuel---maybe fill it up at a differnt gas station (or did you fill it last time at an older station that might have dirty filters or old gas ??)
I would do check this out 1st---
The knock sensors will send data to your ECM and count "occurances of knock") if it pings alot it will reach some majic # of occurances and your spark table will move to the "low octane" spark table--and it has about 1/2 the amount of timing and run like crap-the pinging should disappear aloong with your power---To reset your ECM back to the "hi-octane " table just fill your tank with at least 10 gallons of fresh fuel and it will rest back to the high table--
I would do check this out 1st---
The knock sensors will send data to your ECM and count "occurances of knock") if it pings alot it will reach some majic # of occurances and your spark table will move to the "low octane" spark table--and it has about 1/2 the amount of timing and run like crap-the pinging should disappear aloong with your power---To reset your ECM back to the "hi-octane " table just fill your tank with at least 10 gallons of fresh fuel and it will rest back to the high table--
Those are some interesting thoughts..... For the record,
*my car is an '01, just turned 18,000 miles
*it has the OE tune
*the fuel filter was changed about 5 years ago, just because
it was 5 years old
*I put gas in it about 30 miles before the "incident" occurred
Burning Brakes
Joined: Sep 2008
Posts: 1,147
Likes: 64
From: Mechanicsburg PA
Two years ago I had a bad case of pinging but it was at low rpm when lugging the car. It turned out to be a leak in the intake system, down stream of the MAF. I.e. un-metered air was getting in. Fixed the leak and no more ping.
Melting Slicks
Joined: Jun 2008
Posts: 2,283
Likes: 16
From: Katy Tx
most true pinging happens under load - like lugging the motor even a little. What you describe sounds more like detonation since its happening at higher rpms -- I'd definitely recommend a tune - could be running very lean and could cause some serious damage. Vacuum leaks like mentioned above are sometimes the cause.
Thread Starter
Team Owner
Joined: May 2001
Posts: 87,294
Likes: 1,579
From: Western NY
The OE hose clamps aren't long enough to go around the larger OD of the silicone hose vs. the original plastic parts. I used a HD, black plastic "wire tie" to secure the coupler instead. I checked it, and although it was fairly snug, it did "wiggle" a little when I tugged on it. I installed another wrap, this time getting it a little tighter, and see if that changes anything....
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 326
From: CA.
St. Jude Donor '13-'14-'15
A vacuum leak or an air bridge air leak could cause pinging with a lean mixture during P/T closed loop operation IF your fuel tirms aren't learned our or if they go beyond + 20-25 %--This happens when you get "unmetetered" air in yout intake tract---Most any auto parts house scanners will show you your LTFT fuel trims so you can see if this is the cause
Thread Starter
Team Owner
Joined: May 2001
Posts: 87,294
Likes: 1,579
From: Western NY
OK, guys, here's the update...
I took some time to wash and quickly wax the 'Vette Saturday morning, as it was a little dirty. After that, I took a quick shower, as I had to run some errands, and was going to take the car out and "lean on it" a little, to see if re-securing the air bridge coupler made any difference.
However, Mother nature had other plans, and no sooner did I get out of the shower, a rainstorm blew in out of nowhere. Since the car was all cleaned up, I took my truck to run the errands. The weather was nice today, so I drove the 'Vette to work, was able to get on it a couple of times, and it didn't ping at all. Apparently that miniscule air leak threw off the mixture, leaning it out, and causing the ping.
Thanks to all of you whose suggestions got me heading down the right track!
I took some time to wash and quickly wax the 'Vette Saturday morning, as it was a little dirty. After that, I took a quick shower, as I had to run some errands, and was going to take the car out and "lean on it" a little, to see if re-securing the air bridge coupler made any difference.
However, Mother nature had other plans, and no sooner did I get out of the shower, a rainstorm blew in out of nowhere. Since the car was all cleaned up, I took my truck to run the errands. The weather was nice today, so I drove the 'Vette to work, was able to get on it a couple of times, and it didn't ping at all. Apparently that miniscule air leak threw off the mixture, leaning it out, and causing the ping.
Thanks to all of you whose suggestions got me heading down the right track!
