Detonation or pining?
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Only way to describe it is it sounds like marbles rolling around in a can. That's the best decription so far.
What exhaust mods do you have? Is it noticeable over the exhaust? & what can be done about it?tarch said:
On my car I just have an off-road h with the stock muffs. I can hear the pinging anyway. It's under hard acceleration when you can hear it. A higher octane gas should take care of pinging. I sometimes use 87 but its hit and miss if I get a bad batch and I get detonation. I try to stay with 89 or higher. The name-brand gas seems to be a bit better even with 87 octane. THis does the trick.downsouthman1 said:What exhaust mods do you have? Is it noticeable over the exhaust? & what can be done about it?
I heard it when my car was being dynotuned. WORST sound EVER!! Made my damn toes curl, lol......
Sounds like hitting a metal pipe on a piece of metal REALLY fast.....something you don't want.
Sounds like hitting a metal pipe on a piece of metal REALLY fast.....something you don't want.
twogts4us
15 Year Member
Run 91+ (preferably 93) octane gas. This alone will stop most pinging. Pinging or pre-ignition is very dangerous. It can be from too much timing, carbon build up on the cylinder heads, valves or pistons, cheap gas or any number of other things. Additional octane actual makes the fuel less volitale and lessens the chance of pre-ignition. The A/F mixture explodes before it's time (before the spark plug fires) while the piston is still in its compression stroke, essentially sending a sonic sound wave down the cylinder and rattling the cylinder wall and or piston, which is the sound you hear...now that sounds scary, doesn't it? I am not an expert by any means, and I'm sure someone could put this into better terminology, but this is basically what happens when your car pings. Avoid allowing your engine to ping at all costs.
chevylover
Member
Mine Pings too
I'm not to sure about the piston firing before the sparkplug fires since that is what the plug is for and you can't ignite the A/F mixture without the third side of the Flame Triangle (Fuel, O2, and Heat)
Mine is doing the same thing under hard acceleration above 4K rpms. I just put my first tank of Premium in tonight so we'll see how she runs over the next couple days.
It's got over 70K on what I think are the orginal plugs. I've got a set of Bosch platinums to put in just have to wait to get the chance........unless someone else local wants to do it for me??/??
I'm not to sure about the piston firing before the sparkplug fires since that is what the plug is for and you can't ignite the A/F mixture without the third side of the Flame Triangle (Fuel, O2, and Heat)
Mine is doing the same thing under hard acceleration above 4K rpms. I just put my first tank of Premium in tonight so we'll see how she runs over the next couple days.
It's got over 70K on what I think are the orginal plugs. I've got a set of Bosch platinums to put in just have to wait to get the chance........unless someone else local wants to do it for me??/??
Go HoTO!
New Member
twogt pretty much hit it!
There are a lot of terms floating around for this. Some people think they are interchangable and some do not: knock, ping, pre-ignition. They really all happen because of the same thing - fuel ignites due to pressure and heat before spark.
Older cars will start to knock/ping due to carbon build up. This makes the space smaller which results in an increase in pressure. All cars can knock or ping under the right conditions. Even if you have the proper fuel, under heavy load (towing uphill) and at full throttle on a hot day puts the car at greatest risk for this. Mustangs have knock sensors which help to prevent it.
If your car does this, you need to decrease your timing or use higher octane fuel. It is NOT a good thing.
There are a lot of terms floating around for this. Some people think they are interchangable and some do not: knock, ping, pre-ignition. They really all happen because of the same thing - fuel ignites due to pressure and heat before spark.
Older cars will start to knock/ping due to carbon build up. This makes the space smaller which results in an increase in pressure. All cars can knock or ping under the right conditions. Even if you have the proper fuel, under heavy load (towing uphill) and at full throttle on a hot day puts the car at greatest risk for this. Mustangs have knock sensors which help to prevent it.
If your car does this, you need to decrease your timing or use higher octane fuel. It is NOT a good thing.
I have detonation above about 5000 rpm and higher octane does help out a bit, but I think I have found out what the problem is. If you haven't listened to spreadmans dyno vid, listen to it...his was detonating at high rpms as well and it turned out he had a bad fuel injector. My car makes the exact sound under the same conditions as his did, so I figure I probably have the same problem.
Well after reading this thread I've learned that I'm not experiencing any of these conditions. I'm experiencing something else. Crazy thing is that the owner's manual for my car requires me to run 91 or above. Nearest thing is 93, so that's what I use. I would have to use octane booster or get a Timing Adjuster & retard my timing in order to stop pinging. Thank goodness it's not. I think my problem will be solved w/ a custom tune.
twogts4us
15 Year Member
The Flame Triangle? Hmmm, never heard it referred to in that way, but, OK... So which side of the "triangle" is missing? Heat? In an engine?chevylover said:
Or, how about in a diesel engine...they don't even have spark plugs. Gosh, how in the world do those things work?
By the way, thanks Go HoTO for defending my answers. In addition to increased CR, carbon build-up can glow like a red hot ember and fire the mixture.
DeadLurker
Daily Driven
DeadLurker
Daily Driven
Actually I found the vid but I'm not sure what exactly you were referring to in terms of detonation...are you talking about the beginning part?
http://users.ev1.net/~spreadman/Pages/media.html
http://users.ev1.net/~spreadman/Pages/media.html
chevylover
Member
twogts4us said:The Flame Triangle? Hmmm, never heard it referred to in that way, but, OK... So which side of the "triangle" is missing? Heat? In an engine?
Or, how about in a diesel engine...they don't even have spark plugs. Gosh, how in the world do those things work?
By the way, thanks Go HoTO for defending my answers. In addition to increased CR, carbon build-up can glow like a red hot ember and fire the mixture.
Very good!!! Diesel engines use glow plugs which must be heated before starting the engine so they will ignite the fuel and complete the triangle to produce a flame.
CTGrey02
Founding Member
Scotty is it still doing that? I just backed my timing off 2 degrees to keep it from doing that.
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