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tap tap tap wont go away
Thinker - May 9th, 2009 at 12:25 PM

i ajusted the rockers last week (0.006") it all went fine, i took my beetle for a long drive every thing fine when driving home tap tap tap came and went a couple of times. during the week it got worse so this morning off came the covers to reset them. and to my surprise they where the same as i set them last week (0.006").
has any one come across this problem before.
i have a few ideas, sticky valve, soft springs, arrrr thats it.

its a 1970 bug / 1500 stock as a rock


pod - May 9th, 2009 at 12:39 PM

its not a loose head is it????


Thinker - May 9th, 2009 at 12:52 PM

thats a scary thought but im going to have look

thanks


grumble - May 9th, 2009 at 08:04 PM

The valves aren't hollowed and the screws worn are they,the next option is a gudgeon or piston rattle,these can mostly be eliminated by pulling the plug lead off and unloading the motor,if the noise comes back its most likely gudgeon or piston.


1916baja - May 9th, 2009 at 08:24 PM

I used to have a tap,tap,tap that came and went. Never really located the exact problem but a friend of mine took a look at it, he adjusted the tappets and there was quite a bit of play in the rocker shafts (end to end), so he shimmed them out and now it seems fine. I also found a bunch of bits of steel floating around in my rocker covers earlier but i dont think that solved my problem.


greedy53 - May 10th, 2009 at 06:20 PM

first check the heads are tensioned remove the rockers easy dont get scared than tension the studs to 23 lb the funny thing is its usually the studs under the rockers that get loose the rockers will go back with a bit of carfull fitting


bajachris88 - May 10th, 2009 at 06:34 PM

On a completely different path for your problem,

You using the right oil as well?
Too fine of an oil will not dampen the contact 'knock' of your tappets. Very common prob for using too fine of an oil viscocity in any engine. Is it factory spec oil?


Thinker - May 10th, 2009 at 07:37 PM

thanks for all these options.

as far as the oil, i have not had the car long only done one change and i used Penrite HPR 30 used to run in air cooled bike but was running much higher Comp Ratio so bit hotter and it work well did not sludge or burn to bad.

is there an oil that works better than others in a flat four.

i did notice that there was a lot of gum on top of the heads.

i think i will take off rocker gear clean top of the heads and rocker gear check the valve stems and rocker gear for wear torque the heads get some new adjusting screws and see how it all gos

anything else i should look for while i have the covers off.


REDKG - May 11th, 2009 at 04:53 PM

not sure if it is the same noise. had a motor where a knocking noise came and went. was the gudgeon pin, the retaining clip had come wasn't engaged.


ian.mezz - May 12th, 2009 at 08:58 PM

is it a tappet noise at idle?
you mite have a mark in valve top and when valve turns clearance changes
or driving under load? could be pinging