Trying to figure out a valvetrain noise
12-31-2012, 09:59 PM
#1
Trying to figure out a valvetrain noise
So I did a burnout a week or two ago and I blew both header gaskets. I replaced both gaskets with stockers and the exhaust sealed up great. Once I got the truck back on the road, I noticed the valvetrain was very loud. It has always been noisy because I had the wrong size pushrods in it but I noticed that it was even louder than usual. I had the correct pushrods in my garage, just never had the chance to change them. Since then, I replaced the pushrods with the correct length and the valve train seems much better.
But I am still hearing an abnormal tapping coming from under the valve covers. I can't seem tell which cover it is coming from since it isn't apparent at idle. Once I'm above 1500rpm, the noise is very loud. I tried to get a vid of it from inside the cab but you couldn't really hear it over the exhaust.
It is very apparent with the converter unlocked all through the rpm range. Then with the converter locks, and I give it a little throttle, or put a light load on the engine, the tapping disappears...WTF. I can't figure out if it would be a bad lifter, broken valve spring, ect. Any recommendations?
But I am still hearing an abnormal tapping coming from under the valve covers. I can't seem tell which cover it is coming from since it isn't apparent at idle. Once I'm above 1500rpm, the noise is very loud. I tried to get a vid of it from inside the cab but you couldn't really hear it over the exhaust.
It is very apparent with the converter unlocked all through the rpm range. Then with the converter locks, and I give it a little throttle, or put a light load on the engine, the tapping disappears...WTF. I can't figure out if it would be a bad lifter, broken valve spring, ect. Any recommendations?
12-31-2012, 11:02 PM
#2
So I did a burnout a week or two ago and I blew both header gaskets. I replaced both gaskets with stockers and the exhaust sealed up great. Once I got the truck back on the road, I noticed the valvetrain was very loud. It has always been noisy because I had the wrong size pushrods in it but I noticed that it was even louder than usual. I had the correct pushrods in my garage, just never had the chance to change them. Since then, I replaced the pushrods with the correct length and the valve train seems much better.
But I am still hearing an abnormal tapping coming from under the valve covers. I can't seem tell which cover it is coming from since it isn't apparent at idle. Once I'm above 1500rpm, the noise is very loud. I tried to get a vid of it from inside the cab but you couldn't really hear it over the exhaust.
It is very apparent with the converter unlocked all through the rpm range. Then with the converter locks, and I give it a little throttle, or put a light load on the engine, the tapping disappears...WTF. I can't figure out if it would be a bad lifter, broken valve spring, ect. Any recommendations?
But I am still hearing an abnormal tapping coming from under the valve covers. I can't seem tell which cover it is coming from since it isn't apparent at idle. Once I'm above 1500rpm, the noise is very loud. I tried to get a vid of it from inside the cab but you couldn't really hear it over the exhaust.
It is very apparent with the converter unlocked all through the rpm range. Then with the converter locks, and I give it a little throttle, or put a light load on the engine, the tapping disappears...WTF. I can't figure out if it would be a bad lifter, broken valve spring, ect. Any recommendations?
12-31-2012, 11:48 PM
#3
I will get under the truck and check out the flex plate but I'm almost positive it is coming from the valvetrain.
Ugh I just tried to take another vid by mounting the gopro on the outside of the truck but you still can't hear it. It doesn't make sense to me cause it is so damn loud from inside the cab. Looks like I will pull the valve covers off again and look for anything abnormal. Can you run an LS engine with the valve covers off or does it build too much oil pressure under there? I used to when this truck had the sbc in it but don't know about LS stuff...?
Ugh I just tried to take another vid by mounting the gopro on the outside of the truck but you still can't hear it. It doesn't make sense to me cause it is so damn loud from inside the cab. Looks like I will pull the valve covers off again and look for anything abnormal. Can you run an LS engine with the valve covers off or does it build too much oil pressure under there? I used to when this truck had the sbc in it but don't know about LS stuff...?
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