Valves still tappin'...

[JSiN]

hey was hoping somebody could shed some light on the art of getting these valves adjusted and finally quiet them from tapping... i've now been at them twice, and after the first, they were actually louder, so i took another shot and now they are quieter then before, but still annoyingly loud...
my 2nd attempt i found a few things that i was unsure about, and wanted to ask here to see if anyone had any answers...
so in my research online, as well as the bentley, i know that the valve clearance on a cold engine is .25mm, and this is exact feeler gauge i was using...my first question is with this...on each rocker arm as i was adjusting, i noticed a slight amount of play, meaning you can kinda rock the arm about a mm or so back and forth from the camshaft to the valve. this is a bit confusing to me as there were a few times that before i made any adjustment i used the feeler gauge to check the clearance, and at first it seemed like it was too tight to allow it to slide between, but then i must of rested my hand on the rocker right above the cam, and like i said it 'lifted' the arm that little bit, and my feeler gauge easily slipped between the arm and valve... is this normal???? it just seems like its pretty difficult to get an accurate adjustment with the rocker having this play...
another thing i noticed when making the adjustment is when u have the feeler in place, and u have ur wire or whatever in the hole of the valve eccentric, i would rotate the wire and find a spot where it felt like the feeler was snug....but then for shits and giggles i would rotate like a 1/3 turn more towards the valve and it would still seem "snug"... i guess my point is this whole valve adjusting thing seems like theres a lot of gray area, and not one right-on-the-money spot to where it would be just right.... and the downside to this is after you spend the time bolting everything back together, and turning the engine over, only to hear those f*@%g valves tapping....STILL....

oh, and one more question..... so what is the reason for the actual tapping? meaning is it because the space between the valve and the rocker is too big, or is it bc its too tight/touching? and is there any benefit to having the adjusted one way or the other (loose or tight) ;-)

damn i hope that made a little sense...thx for any input 4sure..
peAce

[wagonizzle]

It is safer to be a little too loose than too tight. You may be experiencing worn out eccentrics, which are slipping out of your adjustment because they are out of round. While I'm pretty sure that they didn't sound like this from the factory, fact is, many M20's tick. Turn up the radio. You also could be hearing the injectors; I know mine are rather noisy.

[jlevie]

Even when correctly adjusted you will get valve noise from a higher mileage engine due to wear in the valve guides and eccentrics. I'd hazard a guess that if the engine has 150k or more you'll never have quiet valves until the head is rebuilt.

The 270k engine that I replaced had loud valves when cold and a noticeable tick when hot. The 80k engine that replaced it has a mild tick when cold that almost disappears once the engine is up to temperature.

The best way to adjust the valves is to use a spring tool on the eccentrics. The one I have came from BavAuto a number of years ago. I don't know if they still offer that tool, but if you can get one it makes the job easier, faster and more accurate.

[StereoInstaller1]

I finally fixed mine.

What I figured out was that the top of the valve stem was "cupped", thus the feeler gauge was not getting an accurate reading.

I carefully adjusted by feel. Now my valves are quiet, but I know a fresh head is gonna be on there soon.

[JSiN]

FINALLY!!!!! last night, for the third time in 3 days, i performed the adjustment, this time spacing them to .27mm(.011 in.), on a cold engine....thats right in between the recommended .25mm(.010 in.) warm and .30mm(.012 in.) cold....i wish i knew exactly what i did differently, other than REALLY REALLY took my time, and adjusted them as precise and consistent to one another as i could....any medical surgeon would of been proud!!!....so once i completed this meticulous task, i figured i was gonna bolt everything back up only to hear them tapping like mad again, but this time.....no sound, no tapping, the valves in perfect symphonic harmony with one another... i have NEVER heard this engine sound so sweet, and strong... so all my tedious labor has most definitely paid off, and im about to celebrate by finding the closest highway on-ramp and sayin p.....e.............a.........................c... ..............................e!!!!!!!!!

btw thx for the couple replies....