Pinging
08-22-2005, 03:12 PM
#1
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Pinging Hi guy's, I have a 02 with about 45k on it and it's starting to ping pretty bad in the mid RPM's, what do you think? Ive heard catch can but I want to make sure
08-22-2005, 03:15 PM
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Well unless you are smoking i doubt its a PCV problem. Can you get your hands on a scantool to see what codes are being thrown? Do you have original plugs and wires? GL
John
John
08-22-2005, 05:24 PM
#3
Shine a light into your throttle body and see if you can see an oil coating. If you do see a shiny oil slick, it's time for a catch can between the pcv and intake and some top end cleaner.
Do you know anyone who has tuning software? They could log some driving conditions and let you really see what is going on.
You're in Cali right? Since you are forced to use the crappy 91 octane, you're car is going to be more sensitive to things like carbon buildup, worn out plugs and plug wires, etc.
Do you know anyone who has tuning software? They could log some driving conditions and let you really see what is going on.
You're in Cali right? Since you are forced to use the crappy 91 octane, you're car is going to be more sensitive to things like carbon buildup, worn out plugs and plug wires, etc.
08-22-2005, 08:32 PM
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Original plugs and wires, thinking about changing them just havent got to it, we checked the TB and it did have oil in it, we cleaned it up but it will probably build up again. I have a little oil consumtion ( I did the GM oil consumtion test and it was "in parameters") think I should do the can and then have it tuned? change the plugs and wires before or after?
08-22-2005, 10:21 PM
#5
Is your car stock? I wouldn't pay for a custom tune just to clear up KR, unless you have access to your own software or can get a free tune from someone. Tuning to eliminate KR and pinging won't correct for the cause of the pinging in the first place. Top end cleaner, a good catch can, a new pcv valve (its probably choked w/ oil & carbon deposits), new plugs, etc should help. You're lucky, my car has >90K miles on it (I'm the 2nd owner) and has only had a catch can on it for ~3K miles. My combustion chambers are probably layered with carbon!
08-22-2005, 11:55 PM
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Pinging is just a sign that you have to correct either a/f mixture or some oil leaks (i.e. piston rings) but there's more to it.
In a normal non-pinging engine, the spark plug fires at the desired time and initiates a spherical flame that moves across the combustion chamber consuming the air/fuel mixture as it goes. This flame increases the temperature and pressure in the cylinder and creates your power. When the combustion chamber temperatures get high enough, it is possible for the air/fuel mixture to spontaneously combust (pre-ignition).
This is what happens when a car "diesels" on runs on after the ignition is turned off. Commonly the source of the ignition is from carbon deposits or simply a sharp edge on the piston or head surface.
When both pre-ignition and regular ignition occur simultaneously, you get two flame fronts moving towards each other. When they meet, they extinguish each other with a loud pop. That pop is the ping. This effect is similar to turning off the acetylene on an oxy/acetelene torch. The ping is not harmful. But it is an indication that there is something amiss, something that may be silently damaging you engine.
One source is excessive carbon buildup. That means nothing is wrong and the engine simply needs a good cleaning, ON THE INSIDE. The reason for the excessive carbon could be due to an oil consumption problem, either leaky valve seals or worn piston rings. Either way, the head needs to be removed to solve the root cause, the can be decarboned at the same time.
An engine is normally good at burning away carbon on it's own. The problem could also be due to mal-adjusted carbs or a dirty air filter causing the engine to run way to rich. Again, that is a problem that needs correcting and a 1/2 bottle of Techron engine deposit cleaner will quiet it right up. In no case does the pinging from carbon cause engine damage.
The other cause of pinging is excessive cylinder temps. As the temps rise, the sharp edges of the piston will ignite the mixture. The excessive temperature will also start to melt the piston. Again this could be due to a number of situations. One case would be a dirty air cooled engine or a water cooled engine with some problem with the cooling system. The other possibly is that engine was designed to run that hot (like a race engine) and simply needs higher octane. This will in time cause engine damage, but it is again and indication of a problem. If the engine is dirty, higher octane will cause the pinging to go away, but it is still running too hot.
Contrary to what the gasoline companies advertise, engines never need to change octane. If a new engine is happy with 87 and at 40,000 miles starting pinging, that means is time for some maintenance, not higher octane. Many european cars and bikes need higher octane because of their better fuels. The US has the "worst" fuel in the world. Germany starts the fuel grades at 96 octane, the their engines are designed to need it. Now, many foreign manufacturers "de-tune" their engines to run on our 87 octane gas. If your engine needed 89 or 92 octane new, then that is what you must run. If it didn't need 92 new, and does now, look for a problem.
Now on the subject of a properly tuned engine pinging. Yes, they should ping, a little under certain conditions. Engineering is a field of compromise. You want the most power, the best fuel economy, the cleanest emissions, and the longest longevity out of any engine. But each of these conditions requires different tuning, generally opposite from each other.
An engine needs to be tuned to operate at a sweet spot that is the compromise of all requirements.
As I said earlier, pinging can be the result of high combustion temps, and this is the type you would expect to occur. High temps are caused by a combination of lean fuel and advanced timing. Lean fuel produces higher combustion temps and hence more power. It also produces higher emissions and potential engine damage.
When the engine is under severe load and a low RPM (like climbing a steep hill in top gear) then engine temperatures rise and will begin to ping. That is normal. That is desired. Yes, you are damaging the engine and melting the piston. (More on that later). That means that you have crossed the line are no longer is that compromise zone. That is good because engines are not meant to be operated in that fashion. PINGING MEANS IT IS TIME TO DOWNSHIFT.
Engines, particularly motorcycle engines, make their power in the upper 1/3 of the RPM range. If you are under severe load, you want the tachometer up near red line. That is where the engine was designed to run and it is by far the easiest on the motor. When you are lugging an engine, the oil pressure drops and the piston rods begin hammering against the crank shaft because there is no longer a high-pressure film of oil to prevent it. Likewise, the crankshaft in turn hammers against the block (or case). In either case, the damage you are doing to the bearings is far worse than the slight amount of aluminum being burned away. If you switch to a higher octane fuel to prevent the pinging, you may not realize you are destroying your bearings.
You could also retard your timing or richen the carbs to prevent pinging under severe load on whatever octane gas you desire. But again, this will mask the bearing damage you are doing. It also moves the threshold of that "sweet spot" downward. Now you will not have pinging under severe load, but you will also not have complete combustion under normal conditions (such as cruising), and that can lead to poor fuel economy and excessive carbon deposits.
In a nutshell, the engine should ping if properly adjusted, under low RPM, severe load conditions. Next, you should use your transmission to avoid those conditions.
In a normal non-pinging engine, the spark plug fires at the desired time and initiates a spherical flame that moves across the combustion chamber consuming the air/fuel mixture as it goes. This flame increases the temperature and pressure in the cylinder and creates your power. When the combustion chamber temperatures get high enough, it is possible for the air/fuel mixture to spontaneously combust (pre-ignition).
This is what happens when a car "diesels" on runs on after the ignition is turned off. Commonly the source of the ignition is from carbon deposits or simply a sharp edge on the piston or head surface.
When both pre-ignition and regular ignition occur simultaneously, you get two flame fronts moving towards each other. When they meet, they extinguish each other with a loud pop. That pop is the ping. This effect is similar to turning off the acetylene on an oxy/acetelene torch. The ping is not harmful. But it is an indication that there is something amiss, something that may be silently damaging you engine.
One source is excessive carbon buildup. That means nothing is wrong and the engine simply needs a good cleaning, ON THE INSIDE. The reason for the excessive carbon could be due to an oil consumption problem, either leaky valve seals or worn piston rings. Either way, the head needs to be removed to solve the root cause, the can be decarboned at the same time.
An engine is normally good at burning away carbon on it's own. The problem could also be due to mal-adjusted carbs or a dirty air filter causing the engine to run way to rich. Again, that is a problem that needs correcting and a 1/2 bottle of Techron engine deposit cleaner will quiet it right up. In no case does the pinging from carbon cause engine damage.
The other cause of pinging is excessive cylinder temps. As the temps rise, the sharp edges of the piston will ignite the mixture. The excessive temperature will also start to melt the piston. Again this could be due to a number of situations. One case would be a dirty air cooled engine or a water cooled engine with some problem with the cooling system. The other possibly is that engine was designed to run that hot (like a race engine) and simply needs higher octane. This will in time cause engine damage, but it is again and indication of a problem. If the engine is dirty, higher octane will cause the pinging to go away, but it is still running too hot.
Contrary to what the gasoline companies advertise, engines never need to change octane. If a new engine is happy with 87 and at 40,000 miles starting pinging, that means is time for some maintenance, not higher octane. Many european cars and bikes need higher octane because of their better fuels. The US has the "worst" fuel in the world. Germany starts the fuel grades at 96 octane, the their engines are designed to need it. Now, many foreign manufacturers "de-tune" their engines to run on our 87 octane gas. If your engine needed 89 or 92 octane new, then that is what you must run. If it didn't need 92 new, and does now, look for a problem.
Now on the subject of a properly tuned engine pinging. Yes, they should ping, a little under certain conditions. Engineering is a field of compromise. You want the most power, the best fuel economy, the cleanest emissions, and the longest longevity out of any engine. But each of these conditions requires different tuning, generally opposite from each other.
An engine needs to be tuned to operate at a sweet spot that is the compromise of all requirements.
As I said earlier, pinging can be the result of high combustion temps, and this is the type you would expect to occur. High temps are caused by a combination of lean fuel and advanced timing. Lean fuel produces higher combustion temps and hence more power. It also produces higher emissions and potential engine damage.
When the engine is under severe load and a low RPM (like climbing a steep hill in top gear) then engine temperatures rise and will begin to ping. That is normal. That is desired. Yes, you are damaging the engine and melting the piston. (More on that later). That means that you have crossed the line are no longer is that compromise zone. That is good because engines are not meant to be operated in that fashion. PINGING MEANS IT IS TIME TO DOWNSHIFT.
Engines, particularly motorcycle engines, make their power in the upper 1/3 of the RPM range. If you are under severe load, you want the tachometer up near red line. That is where the engine was designed to run and it is by far the easiest on the motor. When you are lugging an engine, the oil pressure drops and the piston rods begin hammering against the crank shaft because there is no longer a high-pressure film of oil to prevent it. Likewise, the crankshaft in turn hammers against the block (or case). In either case, the damage you are doing to the bearings is far worse than the slight amount of aluminum being burned away. If you switch to a higher octane fuel to prevent the pinging, you may not realize you are destroying your bearings.
You could also retard your timing or richen the carbs to prevent pinging under severe load on whatever octane gas you desire. But again, this will mask the bearing damage you are doing. It also moves the threshold of that "sweet spot" downward. Now you will not have pinging under severe load, but you will also not have complete combustion under normal conditions (such as cruising), and that can lead to poor fuel economy and excessive carbon deposits.
In a nutshell, the engine should ping if properly adjusted, under low RPM, severe load conditions. Next, you should use your transmission to avoid those conditions.
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08-24-2005, 05:41 PM
#8
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ok lets see, the mods on the bird would be, FRA, lid and K-N, ported maf (same size just ported), descreened, LM exhaust. What I should do first is, top end cleaning, is that something we can do? catch can, clean or buy a new PVC valve, try some techron engine deposit cleaner. These seem to be the first things I should try, am I right? see if that clears up most of my problem and go from there. Robert
08-24-2005, 06:43 PM
#9
Those are the easiest things to try first. You should think about throwing on a fuel filter as well while you are doing everything else.
You said in your first post that the car is pinging at mid rpm, right? Is this a part throttle or wot? Does it go away at higher rpm? Looking at your mods the things that jumped out at me were the descreened and ported maf and the k&n filter. It could turn out to be pinging for other reasons, but alot of people have had problems after modifying their mafs.
You said in your first post that the car is pinging at mid rpm, right? Is this a part throttle or wot? Does it go away at higher rpm? Looking at your mods the things that jumped out at me were the descreened and ported maf and the k&n filter. It could turn out to be pinging for other reasons, but alot of people have had problems after modifying their mafs.
08-24-2005, 08:27 PM
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Actually it happens when I step on it quickly, when I jump to about 4-5g, 3/4, not wot, I didnt know what is causing it so I have been careful, It does go away after a few seconds and after that it climbs with no chatter. It's not happening if I raise my speed evenly and dont jump on it.
