Light engine knock during heavy acceleration
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Light engine knock during heavy acceleration
I'm noticing a light knocking coming from my engine during heavy acceleration. Is this normal or does this mean the engine can't handle heavy acceleration and i should drive like a grandma?
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Originally Posted by vital49
What have you modified on it, if anything?
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Originally Posted by bonnie94ssei
Originally Posted by vital49
What have you modified on it, if anything?
or, are you viewing live data, and picking up kr on a scanner?
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Originally Posted by samueljackson
I think he means that he can actually hear a "knocking" sound.
*Edit* I guess it could be spark knock as the plugs and wires are in need of changing. Think that could be it? Is there a way to tell with an OBD II scanner?
#8
Originally Posted by samueljackson
Originally Posted by bonnie94ssei
Originally Posted by vital49
What have you modified on it, if anything?
#9
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Your description does sound like detonation or spark knock. I wonder if the knock sensors or the PCM they are connected to are not doing their job. They should hear that knock and retard the timing before it is loud enough for you to hear. If the sensors were covered with a thick layer of cooling system sludge, that might mask their efficiency, but that doesn't seem too likely in a car as new as yours. Are the radiator and recovery tank nice and clean?
Even if the knocking were coming from a piston pin or a rod, or some other mechanical source, the sensors should hear it and the PCM should react by retarding spark.
You can test the knock sensors with a scan tool by tapping on the block and watching for the response of the knock counter. A scan tool will also tell you if timing is being retarded, although, if it were, you would probably be able to feel it.
Even if the knocking were coming from a piston pin or a rod, or some other mechanical source, the sensors should hear it and the PCM should react by retarding spark.
You can test the knock sensors with a scan tool by tapping on the block and watching for the response of the knock counter. A scan tool will also tell you if timing is being retarded, although, if it were, you would probably be able to feel it.
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Originally Posted by samueljackson
Originally Posted by bonnie94ssei
Originally Posted by vital49
What have you modified on it, if anything?