Sounds like overheating to me. If the engine is sound otherwise one
thing to check is your oil weight and type. My Super Beetle's oil light
used to come on at low engine speeds. I tried several "fixes" but what
worked was switching to MOBIL 1 fully synthetic oil of the appropriate
weight as stated in the manual. The synthetic never breaks down and runs
cleaner. It does cost more but I think it's worth it.

Later,

Bill Urban
Kansas
"91 Carat