350 Pinging in one Cylinder

[CreativeNotice]

So I've had my 85 c20 with a 350 for almost a month now. Driven it with no problems so far.

Yesterday, I started to hear pinging. Today I started pulling spark plug wires and cylinder 5 is the culprit.  Now, I just replaced the plugs with r45ts, it had r44ts in it when I got it. The auto shop was out of them and the counterman said to use the 45s. Now the pinging started days after I replaced the plugs so this may just be a coincidence. but the recent thread about a 305 pinging has me wondering.

So my questions are: Could going to hotter plugs cause ping in one cylinder only? If it's not plugs causing the issue, what's your first thought.

[zieg85]

Could be a lower grade of gas.  "When you pulled the spark plugs wires, one by one, and when you came to #5 whatever noise it had went away" was the truck at idle?  If that is the case you could have an exhaust leak at #5.

[CreativeNotice]

using the same grade of fuel as always. Yes, it was at idle.

[zieg85]

A ping is usually only heard on heavy acceleration when the timing is to far advanced or the fuel octane is not up to par if everything else in the engine is up to par.  Exhaust leak or loose lifter would be suspect at idle.  A flat camshaft may pop back and make that sound.  Pull the valve cover off and see the movement of the rocker arms on #5, that will tell you if the cam is flat or not

[VileZambonie]

The correct spark plug is R43CTS (P/N 5613810) gap is .045"

You should not have gone to a hotter plug. Put the correct plugs in it first.

[Marc]

Pinging usually sounds like a couple of marbles or ball bearings being shook in a tin can...kind of a randomness to it - not rythmic at all.. 

[CreativeNotice]

@ville, thanks I'll do that first off in the morning.
@marc, thanks for describing ping, I've never heard it before, what I'm hearing now is exactly like you described.

Also, i left out a crucial piece of info. While I hear the ping at idle, I also hear it during acceleration. It's frequency increases in direct relation to acceleration.

[VileZambonie]

I'd pinpoint the noise you hear at idle because it's most likely not pinging at idle or it would be running pretty horribly.