Engine Pinging on Totally Stock Car
12-09-2014, 05:54 PM
#1
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Engine Pinging on Totally Stock Car
Hello all:
I have a 2006 Coupe w/Z51 package, manual transmission, ~34,000 miles. I have noticed intermittently since I bought the car (22k miles in March 2013) that I get occasional engine pinging under light-moderate acceleration at low RPMs and moderate speeds. As an example, going down the road yesterday at approx 50-55 mph in 6th gear on a very slight uphill grade, if I put my foot into the gas pedal I get consistent engine pinging. This is not flooring it, just increasing my cruising speed slowly. I have seen this occasionally for awhile although recently it seems like its happening more often, although maybe that is in my head. I always run Sunoco 91 octane fuel and live in New Jersey at sea level.
When I took my car in for an oil change on Friday at Chevy dealer, I was able to replicate it for the tech with him driving the car. He basically said that this may be a normal condition for a manual transmission corvette, and that I should downshift if I want to do any accelerating.
I countered that the owners manual recommends shifting into 6th gear at 50 mph, that I provided I dont drop below ~1000rpm I should not need to downshift, and that there is probably something wrong with the car.
Is he right or am I?
I have a 2006 Coupe w/Z51 package, manual transmission, ~34,000 miles. I have noticed intermittently since I bought the car (22k miles in March 2013) that I get occasional engine pinging under light-moderate acceleration at low RPMs and moderate speeds. As an example, going down the road yesterday at approx 50-55 mph in 6th gear on a very slight uphill grade, if I put my foot into the gas pedal I get consistent engine pinging. This is not flooring it, just increasing my cruising speed slowly. I have seen this occasionally for awhile although recently it seems like its happening more often, although maybe that is in my head. I always run Sunoco 91 octane fuel and live in New Jersey at sea level.
When I took my car in for an oil change on Friday at Chevy dealer, I was able to replicate it for the tech with him driving the car. He basically said that this may be a normal condition for a manual transmission corvette, and that I should downshift if I want to do any accelerating.
I countered that the owners manual recommends shifting into 6th gear at 50 mph, that I provided I dont drop below ~1000rpm I should not need to downshift, and that there is probably something wrong with the car.
Is he right or am I?
12-09-2014, 06:10 PM
#2
Le Mans Master
I have the same year with the same gearing and mine will ping faintly under similar conditions, regardless of octane. I'm up to 121K miles so far.
That line from the owner's manual is obviously not valid in every situation. If for example you're going up a steep grade WOT at 1000rpm in 6th, you're lugging the motor.
That line from the owner's manual is obviously not valid in every situation. If for example you're going up a steep grade WOT at 1000rpm in 6th, you're lugging the motor.
12-09-2014, 06:26 PM
#3
Yep, 6th gear in a vet is a over drive gear and not considered a next gear in the same transition of gears from 1 to 5,
So looking at it, the gearing goes something like this for a match up to the next gear,
1-2-3-4-5-----------6, hence 6th gear if it was a direct relationship in reduction to the rest off the gears, would something like a 8th gear instead.
So instead of lugging the motor up a hill in over drive, shift down to 5th gear instead (read if you had a auto trans, it would shift down for you instead).
So looking at it, the gearing goes something like this for a match up to the next gear,
1-2-3-4-5-----------6, hence 6th gear if it was a direct relationship in reduction to the rest off the gears, would something like a 8th gear instead.
So instead of lugging the motor up a hill in over drive, shift down to 5th gear instead (read if you had a auto trans, it would shift down for you instead).
12-09-2014, 06:48 PM
#4
Le Mans Master
Dano, is it possible the pinging is coming from carbon build up. I have the same slight knock from my 2007 (28,000 miles) but mine is an A6. Not sure if this is true or not, but I read somewhere that carbon can build up if the car is driven very conservatively for a long period. I bought my car from a 72 year old guy who never pushed the car so I was hoping that was a possibility. I have been running the car using the paddles and getting the RPM up hoping to clean things out. Any thoughts on this theory?
12-09-2014, 08:18 PM
#5
Dano, is it possible the pinging is coming from carbon build up. I have the same slight knock from my 2007 (28,000 miles) but mine is an A6. Not sure if this is true or not, but I read somewhere that carbon can build up if the car is driven very conservatively for a long period. I bought my car from a 72 year old guy who never pushed the car so I was hoping that was a possibility. I have been running the car using the paddles and getting the RPM up hoping to clean things out. Any thoughts on this theory?
With the amount of Techron that we push through the tanks to keep the passenger tank fuel lever sensor from corroding and failing (and the Lucas fuel treatment that I use for the other two fill up when I not using Techron) , Plus that fact that we change the oil more often then just having it done when the tires are replaced to keep the engine clean; what carbon build up are we talking about.
If nothing else, since the spark plugs are good for 100K, might want to pull them to give them a good check/clean them, and put them back in with some anti-seize long before the 100K mark before they need to be replaced. If you are not filling with top tier 93 fuel that has Techron in it, now would be a good time to start adding it to your fuel every few fill ups. Also, when when the last time you changed the air filter. If you have not yet changed it, Napa gold (wixs) is a great OEM filter.
As for knocking with a auto, makes me wonder if the car had a tune, and either the winter fuel you using in the problems, or the trans was tuned, and now holding the higher gear too long instead.
Bluntly, are you talking lug knocking where you are in top gear, the RPM are around 1k or lower and when you give a great deal more pedal, its not shifting down and the engine starts to knock?
Or higher RPM knocking instead?
12-09-2014, 08:33 PM
#6
Le Mans Master
With the amount of Techron that we push through the tanks to keep the passenger tank fuel lever sensor from corroding and failing (and the Lucas fuel treatment that I use for the other two fill up when I not using Techron) , Plus that fact that we change the oil more often then just having it done when the tires are replaced to keep the engine clean; what carbon build up are we talking about.
If nothing else, since the spark plugs are good for 100K, might want to pull them to give them a good check/clean them, and put them back in with some anti-seize long before the 100K mark before they need to be replaced. If you are not filling with top tier 93 fuel that has Techron in it, now would be a good time to start adding it to your fuel every few fill ups. Also, when when the last time you changed the air filter. If you have not yet changed it, Napa gold (wixs) is a great OEM filter.
As for knocking with a auto, makes me wonder if the car had a tune, and either the winter fuel you using in the problems, or the trans was tuned, and now holding the higher gear too long instead.
Bluntly, are you talking lug knocking where you are in top gear, the RPM are around 1k or lower and when you give a great deal more pedal, its not shifting down and the engine starts to knock?
Or higher RPM knocking instead?
If nothing else, since the spark plugs are good for 100K, might want to pull them to give them a good check/clean them, and put them back in with some anti-seize long before the 100K mark before they need to be replaced. If you are not filling with top tier 93 fuel that has Techron in it, now would be a good time to start adding it to your fuel every few fill ups. Also, when when the last time you changed the air filter. If you have not yet changed it, Napa gold (wixs) is a great OEM filter.
As for knocking with a auto, makes me wonder if the car had a tune, and either the winter fuel you using in the problems, or the trans was tuned, and now holding the higher gear too long instead.
Bluntly, are you talking lug knocking where you are in top gear, the RPM are around 1k or lower and when you give a great deal more pedal, its not shifting down and the engine starts to knock?
Or higher RPM knocking instead?
The Ping or knock is not loud but consistent from moderate to hard acceleration from about 2500 through 4000 rpm. After that it goes away. That rpm range has no ping at at with normal cruising.
I am pretty sure the car never had a tune. The guy was 72 years old and said other than oil changes, the car had never been in a service bay.
Maybe it is just the 91 octane. Should I run a bottle of a Techron through every couple of tanks?
12-09-2014, 08:47 PM
#7
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St. Jude Donor '15
"In honor of jpee"
Hello all:
I have a 2006 Coupe w/Z51 package, manual transmission, ~34,000 miles. I have noticed intermittently since I bought the car (22k miles in March 2013) that I get occasional engine pinging under light-moderate acceleration at low RPMs and moderate speeds. As an example, going down the road yesterday at approx 50-55 mph in 6th gear on a very slight uphill grade, if I put my foot into the gas pedal I get consistent engine pinging. This is not flooring it, just increasing my cruising speed slowly. I have seen this occasionally for awhile although recently it seems like its happening more often, although maybe that is in my head. I always run Sunoco 91 octane fuel and live in New Jersey at sea level.
When I took my car in for an oil change on Friday at Chevy dealer, I was able to replicate it for the tech with him driving the car. He basically said that this may be a normal condition for a manual transmission corvette, and that I should downshift if I want to do any accelerating.
I countered that the owners manual recommends shifting into 6th gear at 50 mph, that I provided I dont drop below ~1000rpm I should not need to downshift, and that there is probably something wrong with the car.
Is he right or am I?
I have a 2006 Coupe w/Z51 package, manual transmission, ~34,000 miles. I have noticed intermittently since I bought the car (22k miles in March 2013) that I get occasional engine pinging under light-moderate acceleration at low RPMs and moderate speeds. As an example, going down the road yesterday at approx 50-55 mph in 6th gear on a very slight uphill grade, if I put my foot into the gas pedal I get consistent engine pinging. This is not flooring it, just increasing my cruising speed slowly. I have seen this occasionally for awhile although recently it seems like its happening more often, although maybe that is in my head. I always run Sunoco 91 octane fuel and live in New Jersey at sea level.
When I took my car in for an oil change on Friday at Chevy dealer, I was able to replicate it for the tech with him driving the car. He basically said that this may be a normal condition for a manual transmission corvette, and that I should downshift if I want to do any accelerating.
I countered that the owners manual recommends shifting into 6th gear at 50 mph, that I provided I dont drop below ~1000rpm I should not need to downshift, and that there is probably something wrong with the car.
Is he right or am I?
If you really want to, you can actually shift to sixth at about 42 mph or just over 2100 rpm as long as rpm in that gear doesn't drop below about 1200 or so. Of course, it requires a flat, level road with little to no headwind. By the same token, you can be in any gear down to about 1100-1200 rpm without causing valve clatter or pinging. It's cutting it close though.
12-09-2014, 11:00 PM
#8
Air filter has about 4,000 miles on it. I change the oil every 5,000 and have put two bottles of Techron in the tank in the last 1500 miles. I can only find 91 octane here in California but I always use Chevron or Shell.
The Ping or knock is not loud but consistent from moderate to hard acceleration from about 2500 through 4000 rpm. After that it goes away. That rpm range has no ping at at with normal cruising.
I am pretty sure the car never had a tune. The guy was 72 years old and said other than oil changes, the car had never been in a service bay.
Maybe it is just the 91 octane. Should I run a bottle of a Techron through every couple of tanks?
The Ping or knock is not loud but consistent from moderate to hard acceleration from about 2500 through 4000 rpm. After that it goes away. That rpm range has no ping at at with normal cruising.
I am pretty sure the car never had a tune. The guy was 72 years old and said other than oil changes, the car had never been in a service bay.
Maybe it is just the 91 octane. Should I run a bottle of a Techron through every couple of tanks?
Something isn't right with pings at those RPMs,
It could be the E10/E15 fuel your running, or could be a problem with the spark plugs or wires.
I would start with pulling the spark plugs and make sure that they are gap'd at .040" and clean.
Next I would check the wires for any burns or cracks, and check them for resistance a well (should be 800 ohms).
Note, when you pull the plugs, make sure that the engine is stone cold. On the drivers side rail cover, pop the flexible fuel line off the fire wall hard line with a fuel line connector tool, and slip the cover past the unconnected line. When the fuel rail covers are cold, then love to crack.
As for the plugs once cleaned and gapped check for .040", anti-seaze grease on the plug threads, and he plugs only get torqued to 11ftlbs.
On the boots, a little dielectric grease does wonders down the line when you go to pull the boots again.
As for back to the fuel, not sure that its even possible to find fuel in CA not lased with ethanol at less than 10%, so maybe try some Lucas Octane Booster and Lucas fuel treatment to see if that helps it out. The Lucas fuel treatment seems to help when we have winter blend fuel here, so the reason I use it.
If you still have problem, then might want to have the car data logged to see if the timing it just too advanced for the E-10+ fuel you are having to run.
Last edited by Dano523; 12-09-2014 at 11:03 PM.
12-10-2014, 12:18 AM
#9
Le Mans Master
Something isn't right with pings at those RPMs,
It could be the E10/E15 fuel your running, or could be a problem with the spark plugs or wires.
I would start with pulling the spark plugs and make sure that they are gap'd at .040" and clean.
Next I would check the wires for any burns or cracks, and check them for resistance a well (should be 800 ohms).
Note, when you pull the plugs, make sure that the engine is stone cold. On the drivers side rail cover, pop the flexible fuel line off the fire wall hard line with a fuel line connector tool, and slip the cover past the unconnected line. When the fuel rail covers are cold, then love to crack.
As for the plugs once cleaned and gapped check for .040", anti-seaze grease on the plug threads, and he plugs only get torqued to 11ftlbs.
On the boots, a little dielectric grease does wonders down the line when you go to pull the boots again.
As for back to the fuel, not sure that its even possible to find fuel in CA not lased with ethanol at less than 10%, so maybe try some Lucas Octane Booster and Lucas fuel treatment to see if that helps it out. The Lucas fuel treatment seems to help when we have winter blend fuel here, so the reason I use it.
If you still have problem, then might want to have the car data logged to see if the timing it just too advanced for the E-10+ fuel you are having to run.
It could be the E10/E15 fuel your running, or could be a problem with the spark plugs or wires.
I would start with pulling the spark plugs and make sure that they are gap'd at .040" and clean.
Next I would check the wires for any burns or cracks, and check them for resistance a well (should be 800 ohms).
Note, when you pull the plugs, make sure that the engine is stone cold. On the drivers side rail cover, pop the flexible fuel line off the fire wall hard line with a fuel line connector tool, and slip the cover past the unconnected line. When the fuel rail covers are cold, then love to crack.
As for the plugs once cleaned and gapped check for .040", anti-seaze grease on the plug threads, and he plugs only get torqued to 11ftlbs.
On the boots, a little dielectric grease does wonders down the line when you go to pull the boots again.
As for back to the fuel, not sure that its even possible to find fuel in CA not lased with ethanol at less than 10%, so maybe try some Lucas Octane Booster and Lucas fuel treatment to see if that helps it out. The Lucas fuel treatment seems to help when we have winter blend fuel here, so the reason I use it.
If you still have problem, then might want to have the car data logged to see if the timing it just too advanced for the E-10+ fuel you are having to run.
Tony
12-10-2014, 08:38 AM
#10
Le Mans Master
Tech probably right.
From your description I think you are lugging the engine.
Octane, Carbon Build Up, Timing, Low Spark all can cause detonation.
Best wishes in solving your pings.
From your description I think you are lugging the engine.
Octane, Carbon Build Up, Timing, Low Spark all can cause detonation.
Best wishes in solving your pings.
12-10-2014, 06:47 PM
#12
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
If the car has just been driven around the block so to speak most of it's life and not really driven hard...probably just needs to be pushed a bit to clean it out. What happened with my C6Z.
Check the plugs too.
12-10-2014, 07:51 PM
#13
Melting Slicks
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I wasn't aware of the oil and corresponding drop in octane Anthony, Thanks! I wonder also if the OP shouldn't have the throttle body cleaned just to get rid of the oil buildup.
12-10-2014, 08:06 PM
#14
It would the puddling of oil that can occur in the intake manifold that I would be more worried about. With the injectors at the bottom end of the intake runners, any fuel cleaner in the fuel is not going to help clean that static puddling out of the intake manifold until is sucked up through the runners and into the cylinders.
Also note, when he check his plugs, if the car is burning a lot of oil (such as the above), going to show up on the plugs.
12-11-2014, 05:41 AM
#15
Advanced
Mechanically, what is happening internally, in the cylinder, when pinging occurs? Is it just a spark thing (detonation) or is the piston actually making the sound?
Years ago I had a Ford 300cuin 6 cyl that pinged horribly. Tried unsuccessfully to stop it by adjusting timing, increasing octane, to no avail. Discovered 4 cylinders with holes burned through their tops. when engine was torn down. Compression blew through pistons causing massive oil leaks.
Dave
Years ago I had a Ford 300cuin 6 cyl that pinged horribly. Tried unsuccessfully to stop it by adjusting timing, increasing octane, to no avail. Discovered 4 cylinders with holes burned through their tops. when engine was torn down. Compression blew through pistons causing massive oil leaks.
Dave
12-11-2014, 07:11 AM
#16
Le Mans Master
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Dano, is it possible the pinging is coming from carbon build up. I have the same slight knock from my 2007 (28,000 miles) but mine is an A6. Not sure if this is true or not, but I read somewhere that carbon can build up if the car is driven very conservatively for a long period. I bought my car from a 72 year old guy who never pushed the car so I was hoping that was a possibility. I have been running the car using the paddles and getting the RPM up hoping to clean things out. Any thoughts on this theory?
12-12-2014, 04:56 PM
#18
Melting Slicks
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Mechanically, what is happening internally, in the cylinder, when pinging occurs? Is it just a spark thing (detonation) or is the piston actually making the sound?
Years ago I had a Ford 300cuin 6 cyl that pinged horribly. Tried unsuccessfully to stop it by adjusting timing, increasing octane, to no avail. Discovered 4 cylinders with holes burned through their tops. when engine was torn down. Compression blew through pistons causing massive oil leaks.
Dave
Years ago I had a Ford 300cuin 6 cyl that pinged horribly. Tried unsuccessfully to stop it by adjusting timing, increasing octane, to no avail. Discovered 4 cylinders with holes burned through their tops. when engine was torn down. Compression blew through pistons causing massive oil leaks.
Dave