Knock on startup normal?
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Joined: Aug 2003
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From: England UK
Nope its not normal, looks at a few of my logs, never seen knock on start up.
Wouln't know where to look, if it dosn't knock at any other time its strange to see it on start up. In the stock tune the knock sensors dont read unless above 1.99% throttle
Wouln't know where to look, if it dosn't knock at any other time its strange to see it on start up. In the stock tune the knock sensors dont read unless above 1.99% throttle
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From: OFallon IL.
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From: OFallon IL.
Teching In
Joined: Apr 2006
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Originally Posted by wait4me
There is a minimum timing table, if you set it too high it may do that also.
How about initial adder vs. ETC or IAT. Even though mine looks in line with other bins I looked at.
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From: OFallon IL.
Originally Posted by CamTom12
I know you've got a forged motor, but do you get any sort of piston-slap or other noise before pump-up or warm-up that might cause it?
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From: OFallon IL.
No, I dont think so. As shown in the log, it's only doing it directly after startup. At the same RPM's anytime but startup its not getting that kind of KR. I dont know how to handle this.
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Joined: Sep 2004
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From: Omaha, NE
With some year and model GMs, it is normal to hear knock at start up. Wish I knew which years and models did this but I don't. GM does an engine diagnostic proceedure by over-advanceing the timing at start up to cause the knock sensors to activate. If they did not activate, a check engine light and a knock sensor code was set. On some cars it was more audible then others. I've had a few C4/C5 Vettes that have done that and our 02 6L Escalade does it very loudly.
