Motor Knocking
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Joined: Dec 2005
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From: knoxville tn
Motor Knocking
Hey fellows , I bought my first vette about a year ago ( 96 LT4 ).About half the time the motor sounds like it knocks when it fires up & at shut off.Noticed it right after I bought it never ever does this at any other time or RPM.Car has been dynoed, hit with nos & runs great!!!!!What the hell is this noise?Is it what they call piston slap , so I've heard......
Motor only has 60,000 on the clock...
Motor only has 60,000 on the clock...
Le Mans Master
Joined: Apr 2000
Posts: 6,341
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From: Shelton CT
I think it's normal when starting up cold for LT1's.
I've heard it on 3 LT1's before buying my '92 a month ago, and my '92 with ultra-low miles does it too, for about 1-2 seconds after she sits around overnight or more.
I've heard it on 3 LT1's before buying my '92 a month ago, and my '92 with ultra-low miles does it too, for about 1-2 seconds after she sits around overnight or more.
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Joined: Dec 2005
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From: knoxville tn
Originally Posted by MrNuke
I think it's normal when starting up cold for LT1's.
I've heard it on 3 LT1's before buying my '92 a month ago, and my '92 with ultra-low miles does it too, for about 1-2 seconds after she sits around overnight or more.
I've heard it on 3 LT1's before buying my '92 a month ago, and my '92 with ultra-low miles does it too, for about 1-2 seconds after she sits around overnight or more.
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Wonder if it could be your DM flywheel, they make noise when they start to go bad.
Also, smack the cats with a rubber mallet with car off, if they are bad youll hear the material rattling around, with the engine running sounds like a knock.
Also, smack the cats with a rubber mallet with car off, if they are bad youll hear the material rattling around, with the engine running sounds like a knock.
