noise under valve cover
#1
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Joined: Jul 2010
Posts: 119
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From: Seabrook, Tx
Ok Motorheads Need some Help,
Engine 540 cid carbed motor,hydraulic roller cam, roller rockers, Patriot performance Aluminum Heads with Inconel Ex valves, bob madera custom cam.
Motor has about 225 hrs of trouble free time on it. Approx 625hp.
The problem:
Motor feels like it is on 7 cylinders at idle, and has a definite noise under the stbd side valve cover. Noise is like a hammer hitting something very quickly.
What I have done:
Pulled stbd side valve cover and inspected all rocker arms. Everything looked good. Inspected all pushrods, all good. Reset all rocker arms and tested and no better.
I am not an expert and am looking for suggestions.
thanks in advance,
Flying Tomato
Engine 540 cid carbed motor,hydraulic roller cam, roller rockers, Patriot performance Aluminum Heads with Inconel Ex valves, bob madera custom cam.
Motor has about 225 hrs of trouble free time on it. Approx 625hp.
The problem:
Motor feels like it is on 7 cylinders at idle, and has a definite noise under the stbd side valve cover. Noise is like a hammer hitting something very quickly.
What I have done:
Pulled stbd side valve cover and inspected all rocker arms. Everything looked good. Inspected all pushrods, all good. Reset all rocker arms and tested and no better.
I am not an expert and am looking for suggestions.
thanks in advance,
Flying Tomato
#4
could be a collapsed lifter. How did you set the valve lash? Are all of the adjusting nuts the same amount of turns down. All of the intakes should be the same and all of the exhaust rocker nuts should be the same.
#5
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Joined: Aug 2013
Posts: 1,037
Likes: 3
From: FredVegas, Va
Check the valve springs for a broken one.
Press down on the push rod side of the rocker arm to see how easy the lifter can get pushed down. May need to roll the motor over to get the lifter on the base circle of the cam first though.
Also pull the plugs out and check them.
Oil look ok? No metal ?
Press down on the push rod side of the rocker arm to see how easy the lifter can get pushed down. May need to roll the motor over to get the lifter on the base circle of the cam first though.
Also pull the plugs out and check them.
Oil look ok? No metal ?
#6
(Motor feels like it is on 7 cylinders at idle), does it run like it's on 7 cylinders? Other than a broken valve spring or collapsed lifter, if it runs like a tractor then it could easily be a head gasket.
#7
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Joined: Jul 2011
Posts: 9,594
Likes: 45
From: Ft. Worth TX
Throwing this out as no ears or eyes or hands on your motor. I have seen and this will fool a lot of people. Exhaust manifold gasket leak(s) (blown exhaust manifold gasket). and or a spark plug boot torn - spark arcing / jumping off bottom side of the header or exhaust manifold.
have no idea how many others have seen this but at one time we use to see a lot of HP 500 carb apps and those Gil / Mercruiser manifolds would warp over time and blow the exhaust manifold gasket out. A lot of times it sounded like a hammering valve train noise.
Here is the tip on how to find exhaust leaks and or blown exhaust manifold gaskets. If you have a carb app especially. Go ahead - run motor a fast idle and dump fogging oil down the carb - the smoke from the fogging oil will pour out your exhaust system leaks and or blown exhaust manifold gasket leak(s). If you have an EFI make the soup mix up in the remote gas tank with gas and a lot of 2 stroke motor oil and run the engine on that mix / fuel at fast idle. The same will happen here as will.
Next if it is spark related banging off whatever run the engine in the dark and look for spark jumping if no sight of spark arcing then spray your spark plug boots and wires in very dim lite with a windex bottle. .
next or beforehand if your valve covers are off - use a remote starter or someone at the key and crank the engine over to watch your valve train action to see if you possibly can see and or hear anything out of place in that area. Pull your lanyard or pull your coil wire off at the coil before cranking.
next - a damn good tool is a real Doctors stethoscope - I can not tell you how many times I have FOUND the exact noise problem part by using a real docs stethoscope alone - from pulley bearing noise to crank noise to damn vacuum leaks to valve train noise and so on.
have no idea how many others have seen this but at one time we use to see a lot of HP 500 carb apps and those Gil / Mercruiser manifolds would warp over time and blow the exhaust manifold gasket out. A lot of times it sounded like a hammering valve train noise.
Here is the tip on how to find exhaust leaks and or blown exhaust manifold gaskets. If you have a carb app especially. Go ahead - run motor a fast idle and dump fogging oil down the carb - the smoke from the fogging oil will pour out your exhaust system leaks and or blown exhaust manifold gasket leak(s). If you have an EFI make the soup mix up in the remote gas tank with gas and a lot of 2 stroke motor oil and run the engine on that mix / fuel at fast idle. The same will happen here as will.
Next if it is spark related banging off whatever run the engine in the dark and look for spark jumping if no sight of spark arcing then spray your spark plug boots and wires in very dim lite with a windex bottle. .
next or beforehand if your valve covers are off - use a remote starter or someone at the key and crank the engine over to watch your valve train action to see if you possibly can see and or hear anything out of place in that area. Pull your lanyard or pull your coil wire off at the coil before cranking.
next - a damn good tool is a real Doctors stethoscope - I can not tell you how many times I have FOUND the exact noise problem part by using a real docs stethoscope alone - from pulley bearing noise to crank noise to damn vacuum leaks to valve train noise and so on.
Last edited by BUP; 01-08-2015 at 12:07 AM.






