Knocking / Pinging

[TDaniel]

Hi everyone
I just purchased a new second hand import from Japan Toyota Vitz 2003 facelift model 1.3 with CVT Transmission. It has 60,000ks on it and is in immaculate condition.

When at low revs /under stress when travelling under 70kmh the engine makes a pinging sound. When we put it into sports mode (increases the revs by approx 600) the problem goes away. I have tried a tank of both low and high octane fuel and it has made little difference. Is it a problem with the valves?

Any thoughts much appreciated.
Cheers

[Yaris Hilton]

Light pinging is normal for the Yaris/Vitz/Belta. The engine's knock sensor will pick it up and let the ECU know to retard the spark a bit before it reaches a harmful level. An engine's most efficient spark timing tends to be right at the onset of detonation under many operating conditions.

[127.0.0.1]

probably full o carbon. yank the head and clean the combustion chamber of carbon buildup.

[Yaris Hilton]

No way are those combustion chambers full of carbon at 60,000 kilometers unless that engine's been grossly malfunctioning. Black smoke sort of bad running. A brand new Yaris will ping lightly in normal operation.

[127.0.0.1]

Originally Posted by Yaris Hilton

No way are those combustion chambers full of carbon at 60,000 kilometers unless that engine's been grossly malfunctioning. Black smoke sort of bad running. A brand new Yaris will ping lightly in normal operation.

huh ? mine does not ping whatsoever, and I drive a lotta medium
and stiff grades. knock sensor works. octane is 87

[Rick]

My '08 has a light quiet diesel-like clatter when peaking the instant MPG on the highway. I assume I'm hearing pre-detonation (light pinging) The Chrysler powertrain engineers used to tell me that "pinging is the sound of fuel economy". More recently I was told by a Ford powertrain engineer that "pinging under light loads hurts nothing but pinging under heavy loads will destroy things". I'll let you know if my motor grenades.

[TheSilkySmooth]

Make sure plugs are tight and correct heatrange. Engine can get carboned up by easy driving - a steam drink of 1/2 L hot water at 3000 RMP >SLOWLY< in through a vacuum hose behind the TB but into the manifold log will decarbon the engine better than any solvent. Just go VERY slow. maybe 5mins to drink the 1/2 litre.

[Yaris Hilton]

Originally Posted by 127.0.0.1

huh ? mine does not ping whatsoever, and I drive a lotta medium
and stiff grades. knock sensor works. octane is 87

Your ears likely aren't good enough to hear the light pinging, else you aren't recognizing it. It's there. It's subtle. The knock sensor does work.

[127.0.0.1]

Originally Posted by Yaris Hilton

Your ears likely aren't good enough to hear the light pinging, else you aren't recognizing it. It's there. It's subtle. The knock sensor does work.

yaris does sound like a little buggy. perhaps that is where the little buggy sound comes from. it is nothing like 'real pinging' you'd get from a crappy 1981 chevy citation climbing a steep hill

[severous01]

try running midgrade or premium.

[mimelio]

Try another brand of gasoline just for the heck of it.

[Yaris Hilton]

Originally Posted by 127.0.0.1

it is nothing like 'real pinging' you'd get from a crappy 1981 chevy citation climbing a steep hill

Most definitely not. It's just a very light rattling noise. Got to listen for it.

On really unusually lugging mine down, on occasion I've heard about three distinct knocks (still on the light side) before the ECU retarded the spark.