What does Ping sound like?

Hi all,

I just installed a MPI kit on my 83 CJ7 and all is fine. However, there is a sound that is coming from the engine which I cannot determine what it is. To me it sounds like belts moving but not really. Kinda hard to describe. I've heard there's a problem with Pinging with MPI kits.

What does pinging sound like? How can I determine if my engine is pinging?

thanks in advance,

bill

Reply to
William Oliveri
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The best description I've ever heard for pinging was described as the sound of a ball pein hammer striking a piece of aluminum, which is about the effect it has on your pistons.

Chris

Reply to
c

Pinging sounds like:

If all your hand knuckles where made of metal and you cracked your knuckles., Then you'd know what pinging sounds like. I have bad pinging in my 86 300ZX so I really know what pinging sounds like.

Good Luck,

Reply to
GamePlayer No. 1058

I should mention I hear this the loudest when no torque is applied. That is, at idle and between shifting gears. I don't hear it when applying load either light or heavy.

Is pinging more prominent under load? Does it get worse when more load is applied?

What does pinging tell about an engine? Does it indicate something negative about an engine?

Thanks

bill

Reply to
William Oliveri

William Oliveri did pass the time by typing:

That doesn't sound like pinging.

Yes and Yes. Although it is more audiable usually at high RPMs.

It means your fuel mix is igniting before it should. In serious cases it can burn through the piston and/or throw rods out of an engine. In all cases.. ALL CASES.. Pinging is BAD.

Step up one level in octane. i.e run 91 if your runnign 87 and see if the problem goes away. You may need to flow more fuel.

The other possibility is your hearing things. :)

Reply to
DougW

If you're hearing it under no load conditions, then it probably isn't pinging that you're hearing. Ping usually happens under high load, low RPM conditions and can be caused by many things including incorrect timing, lean fuel mixture, lugging the engine in the wrong gear, poor quality fuel or low octane, carbon buildup in the combustion chamber, oil contaminating the fuel mixture, and many other things. These are the most common however. I'm wondering if you're possibly hearing the fuel injectors cycling? Some of them can be quite noisy.

Chris

Reply to
c

DougW did pass the time by typing:

Usually I don't follow up one of my posts.. but in this case.

Take a piece of plastic tube and put one end near your ear and touch the other to the injector. This will isolate that sound. Just keep your hands out of the fanbelt. :)

Reply to
DougW

Reply to
L.W.(ßill)

That's not pinging... pinging sounds a lot like someone rattling a spray paint can under your hood as you depress the gas pedal (getting faster as you rev higher). There's also "knocking" which is much like pinging both are caused by fuel detonating before or after it SHOULD. I've heard knock described as sounding like shaking "a coffee can full of marbles".

Yes very much so. It's often caused by your engine being starved for air (overly rich fuel mixture), carbon deposits (they get red hot and become basically an uncontrolled source of ignition). Fouled plugs (the carbon on them can glow just like heavy carbon buildup causing the same pre-ignition problem).

A number of possibilities include; Carbon build up, timing being off or worn/slipping timing belt/chain, running gas at a lower octane than what the ignition system is design to use. Air starvation: clogged or dirty air filter: clogged or malfunctioning air sensors (various types of air flow sensors such as Mass Air etc.). A dirty enough throttle body, or Carb.

Anyway what you describe isn't likely "ping" but it does sound a lot like a sticky lifter, if the sound you're hearing is relatively rhythmic but noticeable mostly when you're parked or moving slowly. It could be a lifter. If the sound fades slowly in and out sometimes louder sometimes quite. I'd bet on the lifter.

Reply to
Simon Juncal

I'm curious about carbon build up. Where does carbon build up accumulate and how is it removed?

Thanks,

bill

Reply to
William Oliveri

It builds up on top of the pistons and in the combustion chambers. If an engine is in good mechanical condition (rings, valve guides, etc.), and is properly tuned, this isn't usually a problem. Add some oil or too much gas (rich fuel mixture) and that's when things can go bad. There are decarburizing chemicals that can be added to gasoline or even poured down the carb/throttle body. Some old timers used to slowly pour ice water down the carb while the engine was running, but I personally wouldn't advise that.

Chris

Reply to
c

That's not ping....

Ping happens under load and sounds like a rattling noise. It is caused by too low an octane lighting up under compression. Folks go with a higher octane to slow down the burn, so the gas waits for the spark plug to light it up.

Or they adjust the timing back a bit to compensate like a knock sensor does.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

William Oliveri wrote:

Reply to
Mike Romain

c did pass the time by typing:

Erm.. don't use icewater, that is bad. Just plain ol water dribbled down the intake is enough. The other is to use tranny fluid but it makes one hell of a smoke cloud. Another approach is called a Ferrari tuneup. You get up to speed and with the engine nice and warm, drop it one gear and nearly redline. That breaks up the carbon and sends it scooting out.

Reply to
DougW

Approximately 9/27/03 19:51, William Oliveri uttered for posterity:

The only time I've ever heard pinging that actually had a "pingggg" type sound was on a turboCorvair. Most other cars you just hear a sort of tick tick tick tick noise under load.

Moderate ping won't hurt anything, where moderate is just a few click noises as you hit the gas. Sustained ping tends to do such nice things as ruining rods, rod bearings, or even put a hole right in the top of the piston. The worst pinging is a higher speeds where you can't hear it.

Reply to
Lon Stowell

Approximately 9/27/03 23:31, William Oliveri uttered for posterity:

On the valves, pistons, and spark plugs. An old removal technique that worked nicely for sports cars is the "Italian Tuneup" which works for *light* carbon removal. Put in premium gas or add a good detergent additive. Find a lonely road and from a dead stop, head for the legal limit [or your paranoia speed] as fast as you can. Goal being to run at wide open throttle and heavy load to burn off the deposits. Won't work for heavy deposits on valves or pistons very well, but you can usually feel it work by the second or third time you run it up.

Reply to
Lon Stowell

Reply to
L.W.(ßill)

Theres a product out there called seafoam, can be found at lots of auto stores, that the people on the Nissan Z message forums swear by to get rid of carbon buildup and it "can" smoke like something else while doing the treatment (do it at night if your concerned about the neighbors calling the fire department).

I tried it in on my Z and the first treatment sent plumes of smoke into the neighbors open garage up on the hill, he also happens to be the local sherriff in my small town, but he didnt complain about it.

The second treatement yielded much less smoke, did it solve my pinging problems in my Z, Not a Chance! That would have been too easy.

As for knocking, I dont think knocking at it's early stages sounds like a coffee can full of marbles but more like what the name implies a knock, like someone knocking on your door. I had a knock in my Z's lower end and finally had to replace the motor. The tech thinks it was the piston rod connections being loose causing the knock, I didnt bother to tear down the motor as it was cheaper for my Z to just buy a jdm import used motor from japan.

Good Luck,

Reply to
GamePlayer No. 1058

LOL, got to agree with that.

Reply to
Simon Juncal

Knock as I'm describing it is a combustion related noise, it's basically fuel exploding too early. Other things can knock (rod knock) and even some "knock" can be created if you drive a knocking/pinging engine hard enough (i.e. break it).

Reply to
Simon Juncal

Hmmm... I don't know how one could possibly detect this. After I crank up Eminem on the stereo I can't hear any engine sounds whatsoever. ;-)

Reply to
Joshua Nelson

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