Clacking under the pressure.....
Thread Starter
Teching In
Joined: Sep 2007
Posts: 28
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From: Romeo, MI
Clacking under the pressure..... As the sig states I have an 01' z28 w/ 93k on it, oil always changed religiously, well maintained, recent updates on the car are 7.350 hardened pushrods and ls7 lifters that went in just this past weekend. now on to the problem. While the motor is under heavy load, high torque, there is a LOUD clacking/clatter from the engine that follows the rpm. The harder/further the gas is depressed the louder and more frequent the sound becomes. Been working on trying to diagnose it but I am officially out of idea's. oil pressure when hot is damn near in the red when hot (according to factory gauge...going to replace) and around 25psi upon start up. Also about once every 2-3 weeks i will get a random multiple misfire code popping up. Any idea's? really need help here!
How much preload did those pushrods end up putting on your lifters?
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Thread Starter
Teching In
Joined: Sep 2007
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From: Romeo, MI
I ended up doing the stupid thing and just slapping them in there to get the car ready to drive again, never payed attention to the amount of pre-load i put on them. but figured i would be going with the safer option with the shorter pushrods after the lifter install.
That'd be the first thing I'd check here!
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With all that noise, I'd hazard a guess that they might not have enough...but there's only one way to know for sure.
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Joined: Dec 2004
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From: K-W, Ontario
That ^^^, and possibly the rocker arm contacting the retainer.
With a shorter pushrod, you're likely positioning the rocker arm incorrectly
and giving up some valve velocity as well.
Hopefully nothing is bent, or damaged.
With a shorter pushrod, you're likely positioning the rocker arm incorrectly
and giving up some valve velocity as well.
Hopefully nothing is bent, or damaged.
