clarification regarding engine knock sound.

[Steve]

Hi all, I need some clarification regarding engine knock sound.

From my experience, the only sound I know about the engine knocking is like shaking marbles in a metallic can. So my question is does it have other types of sound that associate with engine knocking (spark knock)? I ask this question because when I do a search regarding engine knock, there are always those words such “detonation”, “pinging” or “rattling” associated to the knocking sound. Are they all same or they are different sounds ?

Topic

[Greg]

They are all different sounds for each engine. Subaru’s for example have some nasty sounding piston slap until they warm up. Sometimes other knocks are from engine accessories. Knocks can come from anywhere you just have to sort them out to find out what they are.

[Mike]

An engine’s valve train can be a huge source of sound.

[Steve]

Thank you all for the reply. But what I need more clarification is about the sounds related to spark knock.

[Mike]

This page has a good explanation of spark knock.

[Rob]

a lot of it can be something under the valve cover.. so one of the first places to check is inside the valve cover and checking that

[Author]

Replies