tezza43

hi iv got code 22 cumming up knock and my cell lights cumming on when hot could the different fuel i put in last time do this i normally put in vpower but i could only get whats called premium unleaded and have herd some gararges been filling there tanks with standard unleaded im really not into engines what does knock mean ? cheers guys

weeebell

iTrader: (1)

Probably fried your knock sensor.



Knock is "detonation" — abnormal combustion
When unburned fuel/air mixture beyond the boundary of the flame front is heated and pressurized by the advancing flame front for a certain length of time, detonation occurs. It is caused by an instantaneous, explosive ignition of pockets of fuel/air mixture. The cylinder pressure rises sharply beyond its design limits, and if it is allowed to persist, detonation will damage or destroy engine parts. The deleterious mechanisms range from particle wear caused by moderate knocking, to holes punched through the piston or head caused by serious knocking.

Detonation can be prevented by the use of a fuel with higher octane rating, enriching the fuel/air ratio, reducing peak cylinder pressure by increasing the engine revolutions (e.g., shifting to a lower gear), decreasing the manifold pressure by reducing the throttle opening, or reducing the load on the engine. Because pressure and temperature are strongly linked, knock can also be attenuated by controlling peak combustion chamber temperatures at the engineering level by compression ratio reduction, exhaust gas recirculation, appropriate calibration of the engine's ignition timing schedule, and careful design of the engine's combustion chambers and cooling system. As an aftermarket solution, a water injection system can be employed to reduce combustion chamber peak temperatures and thus suppress detonation.

sponners

iTrader: (4)

after a ecu reset is it flashing the cel just when the car gets warm or as soon as you give some hoof?