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  View original topic: Is detonation/pinging/knocking/misfire the same thing?
Tellurius Sat Aug 22, 2020 3:54 pm

And how do I tell which I have? Confused

busdaddy Sat Aug 22, 2020 5:11 pm

Detonation, knock and ping are all the same thing, potatos/potatoes, combustion is reaching full force before the piston reaches the top of it's stroke. Sometimes you can hear it as clicking, or a sound like hitting the engine with a small hammer, other times you can't hear and it only shows it happened by inspecting the spark plugs.

Misfire can be a missed spark, or a spark happening n near when it should be occurring. It feels like the engine skips or loses power for a nanosecond.

Tellurius Sun Aug 23, 2020 12:48 am

busdaddy wrote: Detonation, knock and ping are all the same thing, potatos/potatoes, combustion is reaching full force before the piston reaches the top of it's stroke. Sometimes you can hear it as clicking, or a sound like hitting the engine with a small hammer, other times you can't hear and it only shows it happened by inspecting the spark plugs.

Misfire can be a missed spark, or a spark happening n near when it should be occurring. It feels like the engine skips or loses power for a nanosecond.

It sounds like it is a misfire. Do you get a shake of the car that you can feel?

Thanks

Zundfolge1432 Sun Aug 23, 2020 10:56 am

Tellurius wrote: And how do I tell which I have? Confused

https://help.summitracing.com/app/answers/detail/a_id/5007/~/engine-detonation

And to make it more interesting it can be inaudible and this is bad because you don’t know it’s happening.

https://blog.edgeautosport.com/detonation-vs-pre-ignition


https://www.onallcylinders.com/2014/10/20/whats-difference-detonation-pre-ignition/

VW_Jimbo Sun Aug 23, 2020 11:04 am

Pull a plug wire, while the car is running, one cylinder at a time, to determine which cylinder it is.

Tellurius Sun Aug 23, 2020 12:50 pm

VW_Jimbo wrote: Pull a plug wire, while the car is running, one cylinder at a time, to determine which cylinder it is.

I tried it and I found that all spark plugs made the same difference

VW_Jimbo Sun Aug 23, 2020 4:49 pm

Tellurius wrote: VW_Jimbo wrote: Pull a plug wire, while the car is running, one cylinder at a time, to determine which cylinder it is.

I tried it and I found that all spark plugs made the same difference

Then it is not a misfire at idle!

What is the base timing set at?

ashman40 Mon Aug 24, 2020 5:42 am

I would add there is another type of knock that is not directly related to pre-ignition... rod knock. This is a much more sever knocking that basically means the connecting rod(s) has too much tolerance and each time the piston changes direction the rod is slamming against the crank. At this point your engine is in need of a rebuild.

Detonation and pre-ignition can be the long term cause of rod knock. But other things like over heating, lack of oiling and over revving could also cause the rod bearings to break down resulting in rod knock.

I've only heard rod knock once and it was clear that the engine was in need of a rebuild. It was a constant clank from the engine.

Tellurius Mon Aug 24, 2020 11:29 am

ashman40 wrote: I would add there is another type of knock that is not directly related to pre-ignition... rod knock. This is a much more sever knocking that basically means the connecting rod(s) has too much tolerance and each time the piston changes direction the rod is slamming against the crank. At this point your engine is in need of a rebuild.

Detonation and pre-ignition can be the long term cause of rod knock. But other things like over heating, lack of oiling and over revving could also cause the rod bearings to break down resulting in rod knock.

I've only heard rod knock once and it was clear that the engine was in need of a rebuild. It was a constant clank from the engine.

Thank you for your comments. I'm going to the mechanic tomorrow, I will stay with him, he will check the timing. I need to buy a timing light

This isn't constant, so I'm not sure what it is:)

viiking Mon Aug 24, 2020 9:39 pm

Just for information, PINGING is also known in come countries and an older term as PINKING.

Even though the word pinking normally refers to the zig-zag cutting of material with pinking shears.



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