Tapping noise coming from under driver side valve cover.

[skeet85silverado]

My 85 Chevy silverado when i crank it up it starts right up but i can hear a tapping noise coming for under my valve cover i haven't took it off yet. Any one ever had that problem. I can't here it from the inside of the truck only when i lift the hood up. When i put my hand on the valve cover i can feel it also.

[us111]

sound's like it could be a lifter sticking..

[86 GMG]

maybe a rocker arm loose ???? i dont really know to much about heads but my friend and i put rollers on a new (rebuilt) 305cid heads and one rocker will not shut the hell up i personally think its a bad valve guide best to you on figuring it out

[76sierraclassic]

I had that same problem on my 76 GMC. It was a rocker arm that was a little bit out of adjustment. A slight turn on the wrench and everything was better.

Mike

[Brad_Olson]

Does it feel the same if you put your hand on the other valve cover? If it does there's a chance the sound you're hearing could be a leak between the exhaust manifold and the head; sometimes it can mimic the sound of drivetrain noise. Just something you might want to check...

Brad

[Nolowrider]

I had ticking noise before turneds out to be a loose rocker arm. But once you take off the valve cover it is sometimes hard to tell exactley which one is ticking. A good trick I use is to get short (2 or 3 ft) piece of hose and put one end to your ear and touch the other end to the rocker itself. You can definitley tell which one is ticking. Works great. Just double check for a exaust leak.

[86 Red_Bowtie]

Does the sound come from the lower side of the engine? If so then the fuel pump could be causing the noise. It usually sounds like a rod bearing, but it has been known to sound like a tappet noise. This will require a replacement of the fuel pump if that is where it is coming from. If the noise just showed up in the top end, then you probably have (1) a lifter that is failing, (2) a valve that has some carbon on it and it is not seating right, or (3) a pushrod that has some oiling problem and has worn down on the end causing some clearance problems.

[Paso76GMCstepper]

When my engine started doing it it was after new valve cover gaskets. The Mickey Thompson valve covers I have were rubbing on a rocker. I tapped the side of the rocker to ADJUST it and no more noise. Weird but this was my deal. Never hear a thing from them since..