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musiclicker:  I own a shop and think this; We have a stethoscope made for listening to engines, and isolating internal noises. Several things can cause a lifter to tick. The lifter rides on the camshaft, a pushrod goes from there up to the rocker arm, the rocker arm pushes against the valve when the cam comes up on its lobe, and opens the valve. As the lifter moves to the down side of the lobe, the valve spring tension closes the valve. A sticking lifter, bent push rod, worn rocker arm, or weak valve spring, all can cause this noise to take place. Once you isolate the noise to a particular cylinder, then remove the valve cover, and find the reason for the tick. Even carbon can sometimes build up under the face of the valve, and cause this noise. Sometimes a rod bearing can be mistaken for lifter noise, so its important to find the cause, because speculation just won't do in this situation. I have even seen an engine that had been over reved, and it pulled the stud for the rocker arm out of the head some, resulting in a noise. Either way; the valve cover must come off to determine the cause of the tick, so determine which side the noise is on, and work from there. You can check each rocker by moving it around with the valve in the closed position, and usually you can find the one since it will have much more movement than the rest of them. Its easier done with the spark plugs removed, and turn the engine with a 5/8" socket & breaker bar until each valve is in the closed position. When you locate the culprit cylinder & valve; remove the rocker arm, and the pushrod. Roll the pushrod on a known flat surface to see if its bent, and inspect the ends for wear. Blow through the pushrod to make sure its not clogged up. If its good, then put it back in place, but don't drop it down into the engine. You must feel around for the funnel in the lifter it goes down in to. Inspect the rocker arm for wear, or a hole worn in it where the pushrod goes, and any crackes around where the pivot ball goes. Check for a plugged up oil hole where the pushrod goes into the rocker arm. If all checks good, then measure the height of the rocker arm stud compared to the others, and if its pulled out any, you will know right away. If it is; then you must press it back down somehow. This can be done by screwing a nut on the stud until its flush with the top of the stud, and use a piece of brass, or aluminum to sit on top of the stud while you bang it back down with a hammer. Once you have this done; replace the rocker arm, make sure the cam is on the flat area, and not a lobe (giving it lift) of the cam. Run the nut down until it takes all the slack out of the pushrod. Grasp the pushrod between your fingers, and try to turn it. You want to run the nut down just until the rocker arm makes contact with the pushrod. Spin the pushrod, turn the nut at the same time, and when you feel any resistance on the pushrod.. stop. Now, you want to run the nut down 1/2 of a turn more. You will want to do this with the engine warm, and not all the way cold, so run the engine before you do all of this to get it up to temp. There is an alternate way to do this, but it slings oil all over the engine, and must be done with the engine running. Its done like this; back the nut off slowly until you hear a clicking noise, go back down just until the noise goes away, and go another 1/2 of one turn. The engine may act like its going to die, but this is normal, and it will straighten back out once the lifter pumps up again, and its nothing to be concerend about as this is normal. Glad to help out, Good Luck!!!
2008-05-31 06:14:35