All sorts of problems!!
Thread Starter
Teching In
Joined: Sep 2007
Posts: 28
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From: Romeo, MI
All sorts of problems!! Ok to start when the engine is started the car sounds like a damn sewing machine then starts to quiet down as it gets heated up, i have attributed this to the lifters (For now) but the valvetrain noise is getting worse. My POA is to buy some ls7 lifters and swap those with the old ones, and put in some 7.425 pushrods. The car right now has a pretty rough idle and I will get a random multiple misfire code about once every other week. Any idea's on if i have the proper diagnosis. The car also has 93k on it, so that needs to be factored into the overall equation as well.
Joined: Nov 2001
Posts: 34,648
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From: Schiller Park, ILL Member: #317
Have you scanned to see if the misfires are specific to certain cylinders, or is it just a random misfire? (not just codes, but a detailed scanner that will show cylinder specific misfire counts)
Your cam will cause random misfires, especially at idle. The tune may also need to be looked at.
If the lifters are failing, that would certainly aggravate both misfires and valvetrain noise.
I would suggest to go over the usual basics first (if you haven't already), like regular maintenance for spark and air/fuel delivery.
Your cam will cause random misfires, especially at idle. The tune may also need to be looked at.
If the lifters are failing, that would certainly aggravate both misfires and valvetrain noise.
I would suggest to go over the usual basics first (if you haven't already), like regular maintenance for spark and air/fuel delivery.
Thread Starter
Teching In
Joined: Sep 2007
Posts: 28
Likes: 0
From: Romeo, MI
i haven't checked with a specific scanner yet to see if the miss fire is cylinder specific. Have gone through regular maintenance just to make sure it wasn't something fairly simple, and came up with nothing. I haven't had a tune on the car since i installed the cam either. I also have a LOUD "chatter" coming from the motor when the engine is experiencing a heavy load such as loading up the motor at 35mph in 5th gear, I get this noise that i can only describe to you as what sounds like the lifters bouncing off the cam or some kind of valve chatter.
Joined: Nov 2001
Posts: 34,648
Likes: 2,574
From: Schiller Park, ILL Member: #317
