knocking sound
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Teching In
Joined: Dec 2007
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From: Mobile Al
knocking sound I tried the seach button plenty of times and not one person had the same problem as me.I have a knocking sound coming from the top of the motor.My oil pressure dont seem to be all that great either which makes me think something bad is about to happen.The oil pressure is about is about 35 at warm idle.The knock never goes away until you get the rpms up after its warm but then at idle it comes right back.Some of my buddies tell me it could be just a lifter but what do yall think?
Well, maybe a lifter or a bent pushrod. It may be worthwhile to remove the valve covers and inspect the valvetrain. Can you notice the sound coming from one bank or the other? If so, that can reduce the workload by half, but would be a pretty good indicator that it's valvetrain related. Did you do something recently to wound it?
I just remembered that several years back, someone had traced a similar "knocking on the top of the engine" to the damper that sits on the fuel rail. If you have a stethoscope, or even just a long extension, you should probe around to see if the noise is coming from under a valve cover or from the fuel rail.
I have the same problem. Mine is coming from inside the intake on the driver side. Last night I started to lose oil pressure at WOT, but the oil pressure is fine when not WOT. I am probably going to tear it down and do some inspecting.
Thread Starter
Teching In
Joined: Dec 2007
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From: Mobile Al
I used a stethoscope and the sound is coming from bank 1. I bought the car about a week ago and the car was not knocking at all.But when I changed the oil this week to royal purple[ 5w30] it started to knock.I don't know what to think of it but I think when i get the money I'm going to order a ms4 cam kit and change the push rods and lifters and hope that it will fix it. Do you think this is a good idea?
Seriously, though, it would concern me that an oil change would precipitate a knock. The 35 psi at warm idle doesn't seem that bad to me. It makes me wonder whether a 40 weight oil had been dumped in it to quiet up some bearing noise. If it's your daily driver, I'd be very careful with it until you can open it up and see what's going on. If it can suffer some down time, it may be best to take that side's valve cover off and see if you can trace the source of the noise.
Good luck. I hope it works out OK.
Thread Starter
Teching In
Joined: Dec 2007
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From: Mobile Al
I changed the oil again this morning to mobil 1 10w30 just to try something different and the oil pressure was reading perfect after that but the knock was still there.So earlier I seafoamed the car just to see what happened and the knock actually went away! I am very pleased with the results. i went on a small cruise and when i got there was still no tapping knocking or anything. thanks for the help.
