Pinging? or not?

[Anonymous]

Hello everybody -
listening to my engine after I have shut it off, I heard what I thought was pinging. After do a search on here and elsewhere, it seems that "pinging" happens when motor is actually running due to preignition...I don't notice that, but I found the following quote, which pretty much describes it.."switched off the ignition and listened to the bike tinkle and ping quietly, radiating its newfound heat".

It is a GS550 ES/G (86) completely stock ,about 13k miles, all synch'd and recent plug change and oil change, airfilters new....USe med octane gas...

Is this pinging or not? Only hear it after shut down, and mainly from the exhaust headers.

Thanks everybody...


Rob

[argonsagas]

No, that is not pinging. Sounds like that are a normal event that occurs due to heat disspation . The metal parts do not always cool at exactly the same rate, and they make little noises.

Nothing to worry about.


To hear pinging, try letting the bike engine lug down a bit when riding up a hill or rise, in a high gear, then open the throttle just a bit. The engine will still be lugging, but you will begin to hear the little pinging sounds that occur due to the change in mixture and lack of RPMs. As soon as the RPM s go up, the lugging lessens and you drive on normally.

[Anonymous]

argonsagas has it right and amply so, but let me offer a little more for your further edification.

Once you turn an engine off, there are only two kinds of noises engines make: expansion/contraction ticks & pings, and dieseling.

I have never heard a motorcycle diesel, and if yours ever does this it's something to worry about, especially if it sounds like pinging. Dieseling is when your gasoline engine runs like a diesel, igniting the mixture not by way of electrical spark (which is not active once you kill the ignition) but instead by a combination of high temperature and compression. This can be exacerbated by an erroneous (lean, I believe) mixture. This will usually be accompanied by wicked shaking as the engine fires in an erratic, unbalanced way. You will know dieseling when you see it.

Expansion and contraction ticks & pings are just as argonsagas described. Our mixed metal engines and headers bump around a bit as heat is dissipated into the air at different rates, causing the size of the parts to fluctuate slightly - enough to cause slight shifting, which cannot be seen but the vibrations of which can be heard by your ears. Headers, tubular as they are, resonate nicely and thus are the loudest source of this noise. This is perfectly normal.

Pre-ignition or "pinging" is when a lean condition arises in the running engine, and the mix burns before ignition and thus unevenly. This causes an irregular shockwave in the combustion chamber that strikes the rising piston (as detonation happens well before top-dead-center) and causes it to ring, like a little bell. The result is an audible ping.

My advice to you, my man, is to ride that bike for all it's worth. My GS, meanwhile, is sacked with an electrical gremlin that has everything going all loopy on me.

[Anonymous]

You're hearing normal cooling off sounds. The British, I believe, call this "pinking," which may be what confused you.

[Anonymous]

Wheeewwww...Glad to hear the concensus is that my bike is "pinking" and not "pinging" .. .I would have had to discipline the little bas&^d!!! Well, at least "pinking" is normal....