Thread: Pinking

Pinking sounds like the new term for the young'n about to do something silly! I think you are referring to pinging.

Normally happens on HC motors with low quality/octane fuel when labouring an engine.

Also effects low compression engines with similar circumstances, could also be a case of the injection system needing a flush.

I'm not an expert on the topic though. I'm sure there are a lot more knowledgeable people here than I.

Cheers
Keithy

Pinking is what my Dad used to call it. I thining pinging has the same meaning in this instance.

What fuel are you using? As Keith says, low octane fuel is the usual suspect. I never had any issues running the "regular" crap grade when I had the LC engine. I use a minimum of 95 now I have the HC engine.

Would a faulty knock sensor also cause it? I haven't had much to do with them over the years?

Pinking is the term we used 40 odd years ago when doing mechanical apprenticeship but we had carburetors and distributors and adjusted timing and such our selves i am not conversant with electronic systems and that is why i asked. Thanks for the replies so far i appreciate new ideas and knowledge it makes life interesting.

Gippy

Hi

My motor used to do that.

Too low an octane fuel is the cause, but shouldn't really happen too often. and only in extreme circumstances. Steep long slow grinding hills are a significant contributor and I had a prob on these.

My issue was resolved by replacing the viscous fan as it was locking up, but not fully. Heat and pressure in the block is the initiator of pre-sparking ignition and in my case the extra cooling solved it 98%.

Check the timing not too advanced - i.e. spec.
I've had tanks of fuel that must have been low grade and with excess throttle, high loads off its goes. I carry a bottle of octane booster (get from Supercheap or whatever) and add that in case of a crook batch - only ever happened when refueling in remote little used servos'

I run my hi-comp 4.2L on 95 octane during the cooler months and 98 if I can orchestrate on hot days. Runs fine on 91 hwy cruising on cooler days.
Clive

The "official" term is indeed "pinging"...
Generally caused by the engine not retarding sufficiently under load thereby causing pre-ignition. Also carbon deposits resulting from an overly rich mixture can form hot spots causing low octane fuel to detonate like a diesel engine.
The amount of advance/retard on GEMS and Thor engines governed mainly by the database in the respective ECUs. The degree of ignition advance tends to be optimised for performance but is reduced when detonation is detected by the knock sensors which are (usually) a pair of microphones (one for each cylinder bank) tuned to the frequency of the "pinging" noise. When pinging is detected, a signal is sent to the engine management ECU to retard the ignition...
I agree with the other comments... run a tank of 98 octane through the system and see if it improves. If you can get hold of a borescope see if you can detect carbon deposits in the combustion chamber...

Hi

I think the correct technical term is "Pre Ignition" and I have heard it referred to as "pinging" and "pinking"

Low quality (octane) fuel is the most likely cause, it can also be caused by excessive carbon build up in the combustion chambers.

Given the electronics involved, I doubt that ignition advance has anything to do with it.

Do you have any diagnostic software? Even a generic one may show up some fault codes

Steve

Thanks for the input i will give all suggestions a try and see how we go.

Gippy