now i need help. my car started this whole "octane knock" nonsense. Some ppl call it pinging. Can anyone explain to me the definition of pinging is? and how can i get rid of it? it doesnt do it that much, but when it does, its annoying. pls, help...

 

Pinging, properly known as pre-ignition, happens when the fuel in the cylinder ignites due to pressure rather than when the spark plug fires. Cure is to use a higher octane fuel.

 

Ans since the CL has the EGR & MAP sensors to help eliminate this I'd bet 1 of those are bad. If your hear pinging you have either a fuel or spark problem. That would lead to questions like...

How many miles on the car?
When was the last time you cleaned the sensors & TB?
How are your spark plugs?
Are you using 91+ gas?

 

ok, i have 127k on a 01 cls. i havent cleaned the tb or the map sensors. ill do that on tuesday and see what happens. i jus changed the plugs about august of last year (what a headache) and i only use premium gas. any suggestions?

and thanks ZIPPEE for the definition.


i also cleaned the fuel system about three months ago. this jus started happening about two weeks ago, atleast i noticed it two weeks ago.

 

Are you sure you got the correct plugs? You may want to take a few out & check them. If they seem burnt or oil soaked you have a problem.

 

wat plugs are recommended? i used bosch double platinum...

 

Not those. That may be your problem.
NGK PZFR5F-11
or
DENSO PKJ20CR-M11
The CLS also takes an Iridium plug not platinum.
They should also come pre-gapped to 0.044" = 1.1mm

 

Thanks fuzzy. Will fix that tomorrow. man, i love this place.