Pinging

[WhiteSnake74]

Hi,

I've been trying to find out what's causing what sounds like detonation on my 04 Cobra. It only occurs at WOT or when pushing a bit hard the throttle on low rpms.

These is what I've done so far:

1- Cleaned the air filter
2- Removed MAF Sensor and cleaned it with CRC MAF Sensor cleaner.

Still no luck so,

3- I removed the custom tune and intalled the original Pulley Tune from the Predator.

After each of those procedures I disconnected battery so the ECU could re-learn the fuel curve.

Am I missing something?

The car runs great other than that.

These are my mods:

2.80 Pulley
K&N FIPK II
Mac X-Pipe
Magnaflow Cat-Back
Predator Pulley Tune

Thanks!

**UPDATE - Second page / Post #34

 

[GT Shadow '03]

Some bad gas maybe, or gas that's not at it's rated Octane level at the pump.

Did you try some Octane boost at any time - might be worth a shot.

Might want to check your plugs as well, make sure they not fouled out.

 

[Cypher-M1]

is it loud enough to hear? i assume so? maybe try some fuel system cleaner and try another tank of gas.

if its pinging under stock tune then I wonder if its really detonation, have a datalogger?

 

[WhiteSnake74]

Forgot to mention that I also checked if it was bad gas.

I always use Shell 93 Octane and a few weeks ago I tried a fuel system cleaner (Techron).

And it still does pings.

 

[WhiteSnake74]

I haven't checked the spark plugs yet. I have a new set of TR6's waiting to be installed.

I bought them cause my current TR6's have almost 3 years. But I assumed the weren't bad cause I haven't noticed any hesitation in idle.

Could it be a bad spark plug? Can a bad spark cause detonation?

As I said, the car runs great and I haven't noticed any hesitation.

 

[GT Shadow '03]

Typically, the plugs wouldn't cause a pinging condition since the timing is controlled by the engine computer and ignition module.

But under the correct set of circumstances such as running the wrong heat range spark plugs will lead to pinging. Also, if the plugs have been in for 3-yrs. as they age the electrodes wear which increases the distance between the electrodes which in turn leads to a gradual increase in the firing voltage required to jump the gap. The gap on a standard spark plug grows about 0.00063 to 0.000126 inch for every 1,000 miles of normal driving, which means the firing voltage requirements creep up about 500 volts for every 10,000 to 15,000 miles of driving. Eventually the plugs firing voltage requirements under load exceed the ignition system output resulting in a misfire. But most plugs foul out long before they are worn out.

Besides all the technical jargon above, you might also find one of the COP may not be fully seated.

After 3-years w/same plugs in, it's certainly worth replacing them and eliminating them as a possible culprit.

 

[CobraBob]

I would hook up a wide-band and check your A/F and timing. That might give you a clue as to what's going on. It's at least a good start.

 

[03cobramanIII]

at what rpm does it ping? does it ping like an old 68 chevelle with bad gas? like can you hear it ratting in the engine compartment? or do you hear it under the car like in the mufflers?

on my car every once in awhile i will hear i tink tink under the car like from the exhast only at 2100 to 2250 rpms on interstate in 6th gear, whan i give it a little gas to pass someone it tinks a little more?

i dont know if it the gas ? or if its car car flexing? i got f/l frame connectors.
but i never hear it rattle from the eng.bay

 

[WhiteSnake74]

Typically, the plugs wouldn't cause a pinging condition since the timing is controlled by the engine computer and ignition module.

But under the correct set of circumstances such as running the wrong heat range spark plugs will lead to pinging. Also, if the plugs have been in for 3-yrs. as they age the electrodes wear which increases the distance between the electrodes which in turn leads to a gradual increase in the firing voltage required to jump the gap. The gap on a standard spark plug grows about 0.00063 to 0.000126 inch for every 1,000 miles of normal driving, which means the firing voltage requirements creep up about 500 volts for every 10,000 to 15,000 miles of driving. Eventually the plugs firing voltage requirements under load exceed the ignition system output resulting in a misfire. But most plugs foul out long before they are worn out.

Besides all the technical jargon above, you might also find one of the COP may not be fully seated.

After 3-years w/same plugs in, it's certainly worth replacing them and eliminating them as a possible culprit.

My next step will be replacing the plugs to see if that helps. What will be a perfect gap for the TR6's? (Keeping in mind that we have a very hot and humid weather here in PR, 88+ degrees).

My car has 3.5 years, but only 20k miles. So the sparks may have only like 13k miles.

Sorry but what is the COP?

 

[WhiteSnake74]

at what rpm does it ping? does it ping like an old 68 chevelle with bad gas? like can you hear it ratting in the engine compartment? or do you hear it under the car like in the mufflers?

on my car every once in awhile i will hear i tink tink under the car like from the exhast only at 2100 to 2250 rpms on interstate in 6th gear, whan i give it a little gas to pass someone it tinks a little more?

i dont know if it the gas ? or if its car car flexing? i got f/l frame connectors.
but i never hear it rattle from the eng.bay

I hear it mostly at WOT with the windows closed and the radio and A/C turned off. It's definitely coming from the engine bay. I hear it around 4K RPM's.

And if I'm in 5th or 6th gear and give a little gas, I can hear it too.

 

[Cypher-M1]

COP is Coil on Plug

 

[WhiteSnake74]

Oh, thanks! =)

 

[04CobraMatt]

What will be a perfect gap for the TR6's?

with a 2.8 upper around .32 / .34

Copper plugs should be replaced once a year at least. If you want to keep them longer get the Iridium ones.

 

[WhiteSnake74]

with a 2.8 upper around .32 / .34

Copper plugs should be replaced once a year at least. If you want to keep them longer get the Iridium ones.

Thanks 04CobraMatt!

I will replace them soon to see if that was my problem.

If the pinging continues after plugs replacement, I will go to a dyno to know where exactly the A/F and timing are.

 

[dezracer]

I had same thing after Mile-Hi mail order tune. We tried adjusting it to no avail. The only thing that worked was the canned pully tune from Predator. Now I have custom tune From Dyno Dan and no ping.

 

[thomas91169]

its not a squealing belt is it, that could be confused as a WOT ping?

 

[WhiteSnake74]

I had same thing after Mile-Hi mail order tune. We tried adjusting it to no avail. The only thing that worked was the canned pully tune from Predator. Now I have custom tune From Dyno Dan and no ping.

I removed my custom tune and reinstalled the canned pulley tune from Predator.

I can still hear the ping.

Next step: New Spark Plugs. Analyze the current plugs to see if there's something wrong.

I will also check the belt as thomas91169 said.

 

[03cobramanIII]

I hear it mostly at WOT with the windows closed and the radio and A/C turned off. It's definitely coming from the engine bay. I hear it around 4K RPM's.

And if I'm in 5th or 6th gear and give a little gas, I can hear it too.

ok so your hearing at from the eng bay even in 6th gear , ok i just mine not pinging then, my like coming from under the seat area like exhast loose or something
you need to get that taken care for right away. try amazon for a tune!

 

[WhiteSnake74]

ok so your hearing at from the eng bay even in 6th gear , ok i just mine not pinging then, my like coming from under the seat area like exhast loose or something
you need to get that taken care for right away. try amazon for a tune!

When I said 6th gear and suddenly give a little gas, I meant cruising in 6th gear, not WOT. Enough gas to see the boost gauge responding.

Pinging in WOT can be heard around 4K-5K RPM's.

 

[djtyau]

Do you have any JLT PCV Pre-Filters? I know my passenger side started to lean to the side causing the rubber grommet to open up. I think this was allowing for unmetered air. I was getting some slight pinging only in 4th at WOT. The pinging was only for a second or two, but you could hear it. As soon as, I fixed it with some better tubing my problem went away. Hope this helps.