Lifter hitting Valve Cover

I have a 99 SL1. One of the lifters is hitting the top of the valve cover, causing a loud knocking or clicking when I am idle, and it gets worse as I accelerate. The lifter hitting was changed and so was the valve cover and it didn't fix this problem. Has anyone else had this problem? Any suggestions would be greatly appreciated.

the lifter was hitting the valve cover? i don't think thats possible. the rocker arm is in the way, and for the rocker arm to hit the valve cover the valve cover would basicly need to be dented in. a rapid ticking noise is commonly caused excessive lifter to rocker arm clearance, causing the lifter to hit the rocker arm every time the camshaft spins instead of it staying in a constant contact. the lifter is automaticly adjusting via oil (hydrualic) pressure which will make the lifter want to expand to fill that gap between the rocket and lifter. if the lifter is not supplyed with enought oil pressure, it not be able to expand or "pump up". this tick is also more common with the engine cold, as the oil is to thin to fully pump up the lifters. so what to do:
1. change your oil and filter - dirty oil will restrict oil flow to the lifters
2. use the proper 5W-30 or 10W-30 - other viscostys have different thicknesses and therefore different flow and pressures attributes.
3. maintain you engine - namely, such as in the case of the old engine out of my '94, worn timing chain guides resulting in debris thru out the engine and oiling system.

i have a feeling thats more info then you were expecting...

I have similar problem - 1993 SL1, Meineke had said the valvle cover was leaking, so they put in a new gasket ( and globs of sealant). Apparantly they "cleaned" the valves or something because now it sounds like there's a woodpecker in my engine. They said they would just re-do the oil with 20w-50. What the f#$@!? Is it worth getting someone else to look at it? It's annoying, but what would it take to fix it? How much?

using 20w-50 is at best masking a problem, or at worse going to do more damage. those valve cover gaskets arn't a uncommon problem, and it is very easy to use to much sealent. now lets assume that if the excess sealent(properly named RTV) runs over on the outside, it can very easially run over on the inside as well. yes you should have the problem investagated, but i wouldn't use that shop, but meineke should be held responcible if it becomes appearent that are at fault, perhaps you should talk to the store or district manager and see if the work can be done by a different meineke(i don't trust anyone that recommends using 20w-50 in a 5w-30/10w-30 engine, i've done it and trust me, it makes things worse)

either that or you just developed lifter tick.

the only time you should use that thick of oil is if its like summer and you have a turbo or supercharger (requiring line of oil from pan) or if it sees high revving or like much abuse on a track.