My 1999 Beetle with ALH engine, shortly after after buying it with 100000 miles I had a cam follower (lifter) come apart. The top of it was worn so thin that the hydralic cylinder nearly came thru the top and the top separated from the side. It broke the hydralic cylinder loose from top and the top stuck under the cam lobe to the side of the lifter well in the head. I replaced the head with a used head with "40000 miles on it". 10000 miles later it happened again and now in addition to the one that came apart there are several that worn nearly thru the metal on the top and you can see the hydralic cylinder starting to push thru the top. Has anyone seen this. I replaced all the lifters with some I ordered "cheap" Amiata ones. I also had a new cam but the slot for the vacuum pump was too narrow (?AHU cam). I have ordered new OEM cam and followers from Bora Parts. Is this just substandard original lifters?