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
its not a loose head is it????
thats a scary thought but im going to have look
thanks
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.
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.
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
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?
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.
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.
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