Hello,

How do you identify a pinging sound? Does it sound like a knock? Does it sound like a rattle? Does it sound like tin rattling or does it have a bit more of a bass sound?
When does it happen?, during acceleration?, cruising? or is it constant? Is it loud or is it soft?

Any info will be great.
Thanks,

Nick.

Yeah - it sounds like a tin rattle. Put a marble in a glass jar and give it a shake. That is pretty much what it sounds like (or take a Magna/Sigma for a drive...... he heh hee)
I happens under load, say if your in 3rd going round a sweep corner and you plant it coming out

Not good.

Like marbles shaken up in a glass jar & heard from a distance. Always under load usually when "lugging it"- ie heavy load at low revs ( just before your change down) but can be at any revs under load if settings are bad enough. Nasty- can cause damage over long periods.

Well, I don't know what it sounds like, and I have owned Magnas... When in Adelaide have a look thru the factory and see How a GOOD car is Made....
Sorry this has nothing to do with VWs.
Just commenting on VW74l about pinging..
Pinging is a VERY Bad Sign & Can cause serious Damage to Your Engine...
Its something I would like to hear at a VW show to know what it sounds like...
:o:o:o:bounce

My first experience with pinging was with an 80 Smegma. The dist drive gear came off the crank with some sort of sintered bronze drive gear.
The car would ping like hell, we put a timing light on it and it danced all over the place from 20 before to 30 after.
The bronze gear wears and causes it to not hold a steady time. A few mechanics have told me this is a common problem with them and the same design was carried over into the Mugna.
Most of the Mugnas and Smegmas i hear go past i notice casuse i hear that familar ringing noise when they get close.
That Astron motor would be my LEAST favourite donk ..... and i have driven several including Escorts and Simcas!
Just my opinion.

[Edited on 16-1-2003 by blue74l]

My description of pinging/ knocking/ detonation in the VW engine is a "harsh uneven clicking" sound.

It's very distinctive, and once heard you KNOW what it is.

It's easy enough to test for - in a bug, floor the throttle in 4th gear at 30 mph (50kmh) - in other words, a heavy engine load at low RPM. In a bus or Type3 (with different gearing to the bug) you just have to find the minimum speed for 4th gear and floor it at that speed.

You can occasionally here it for a moment as you take off in 1st gear at the lights on a very hot day if you don't get the revs high enough. This can be because the timing isn't set quite right, and it can also occur with an old distributor - if the return spring has gone a little soft and is allowing the vacuum advance in a little too fast for the rpm.

It's more likely if you are using ethanol blend petrol too - ethanol causes the engine to run lean (because it contains used oxygen so there is less "fuel" in the fuel), and lean means hot, so detonation is more likely. That one is easy to fix though - for every 10% ethanol in petrol, increase your main jet by two sizes - from 125 to 130, or 127.5 to 132.5 for example.

10% ethanol results in 3.9% lean running, and two sizes of Solex main jet change the fuel flow by 4%.

Yes - ethanol in petrol increases your fuel consumption!