Engine temperature for beginners. As standard your bus does not have a temp gauge. Some people fit an oil temp gauge as a guide but if that sounds too tech here are the old lags methods that have worked for ever. Mine's a type 4 engine but the comments work for Type 1 lumps too. What causes overheating? Too lean a fuel mixture is one. Not so much the idle mixture as that only affects, well, idle, or tick over. It is caused by having the wrong main jet, usually on aftermarket or second hand carbs. Lean fuel can cause your valves to burn out so its wise to check. The easiest way is to look at your spark plugs. A good guide to spark plug health is given here http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp Bad air cooling is another common one. There are lots of "experts" on engine tins on here but I subscribe to the theory that if VW put the tin on there it was there for a reason. Make sure they are all present. Your oil cooler is very important here too as it is it also helps cool the engine by controling bearing ,crankshaft, and inner engine temp. The tins and flaps connected to the thermostat control both air and oil cooling. Your thermostat should be present and working. Your flaps (in the top of the fan housing) should be working too, as they control cooling air to the oil cooler, cylinder heads and barrels. On a type 4 a good check is to grab hold of your oil dipstick after a good run, say 20-30 miles. It chould be warm but not hot. If it's too hot to touch you have a cooling problem. Place your hand on the top of the crancase behind the distubutor - that should be comfortably warm, again if its hot - trouble. The original design of a VW air cooled engine was that it should work in central europe at -40degreesC and in the sahara at +40degreesC and be able to run all day without overheating, which very few watercooled cars of the day could match. That's why they last so long, but only if they are running as designed.
Dipstick test for me everytime. I have thought about fitting an oil temp guage, but have decided it's just one more thing to worry about! :-
