Cars using biofuel typically have problems with injection pump failures; symptoms can include a "no start" condition or external pump leaks.
Car Problem Reports
Volkswagen Golf TDI Vehicles Using Biofuels May Have Injection Pump Failures
Volkswagen Golf TDI Problem
Engine Affected: 1.9L 4 Cylinder Diesel Turbo
Visitor, 1996 Volkswagen Golf TDI, 1.9L 4 Cylinder Diesel Turbo, 204,000 mi
Seals in Injection pump started leaking. Installing new seals as they leak.