Can Someone Please Give Me a Definitive Answer On This?

If a car knocks/pings when being driven, but does not make the same
noise at all when the car's in park or in neutral, can it still be
considered to have the same problems normally associated with cars
that are knocking/pinging because of octane deficiency, carbon build
in the engine, misfiring of the pistons and etc?

I've posed this question to many people and I seem to get many
different answers and has now confused me even more than ever. Thanks
for your time and courtesy.

 

Sure. Most pinging typically only occurs when the engine is under load.

 

Super, thanks, Eric!

 

I agree with the intelligent poster that told you that the knocking or
pinging almost always occurs when the vehicle is under load such as when
you are going up a long grade. If you have an older car, you can reduce
the pinging by adjusting the timing--the timing needes to be slighly
retarded. On newer Honda Accords--they have a knock sensor that
automatically retards the timing when a knock is detected. The timing goes
back to normal after the sensor no longer detects or notices a knock or
ping. Older cars don't have knock sensors.

 

NIssan MAximas have had knock sensors since 1993 also. Perhaps other
vehicules have had them also.

 

You will notice engine pinging when said engine is under load, i.e.,
it's in a state OTHER than just idling..."driving about" if you will.

A rising/uphill grade -- when the engine is under the MOST severe load
-- would for sure show any pinging IF it's going to happen, but just
be aware that it can happen when the engine is in ANY other state than
just at idle.

Just use the minimum octane your car requires (as per the Owner's
Manual) and you'll be okay.

John D.

 

Hi,
New cars prevent that via knock sensor and ECU.
Tony

 

Yes, but the original poster asked about a "hypothetical" car that
that IS pinging in one situation but not in another. I was just
addressing that.

John D.