knocking and pinking - what's the difference?

Are they the same thing or different? Pinking is a sort of ping sound isn't it? One of my dad's old cars did it once and my dad couldn't hear it cos his hearing's buggered but me and my mum could and he didn't believe us til the garage told him.

Anyway what causes pinking and what's the difference from knocking?

Reply to
neutron
Loading thread data ...

The message from "neutron" contains these words:

Pinking is the fuel igniting too early and the pressure meeting the piston coming up making what I've always thought of as a "ticking" sound. Usually caused by the ignition being set too far advanced for the conditions, though there are other causes.

Knocking is the fuel igniting at the right time but burning explosively instead of smoothly. This was why lead was added to fuel - tetraethyl lead absorbs infrared strongly and prevents the radiation from the initial ignition setting the rest of the charge off in on go. Can be caused by all sorts of things, but the wrong grade of fuel is a good place to start.

Reply to
Guy King

So does the pinking noise usually happen at low revs or high revs when timing is wrong?

And knocking happen at all revs? If the CAT gone, will that cause the knocking noise?

Reply to
skyline0023

Pinking is most noticeable at low revs when accelerating, i.e. when the engine is under load. That's when I always notice it anyway.

Reply to
neutron

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.