Jerry,

I cannot say for sure that the two o-rings are the same size, but I think that they are.  Your local VW dealer may have one in stock.  I think that this is a common o-ring with the Golf engine.  Again I cannot say for sure, but try there first.  I ordered one from Ken Wilfy about a month ago and he delivered.  Mine too was leaking.

I jacked up the van and crawled underneath with a big turkey roasting pan to catch the spill.  Then in less than two seconds I pulled the old temperature sender, put the new o-ring on the sender and pushed it back into the t'stat housing.  Advice:  move quickly because coolant is pouring down on you.  My system lost about two cups by moving quickly.

I did not bleed out my cooling system after this operation.  I poured the spilled coolant back into the engine and cranked her up.  No problems.  The loss of two cups at this point did not let an air bubble into the cooling system.  I had good luck by moving quickly, but no guarantees.  Hope your experience is equally positive.

PS - don't use the turkey roasting pan for food.

Good Luck and drive safely,

Dennis Lockwood
91 Carat
Original Owner