300tdi mpg

My 300tdi used to do 160 miles to half a tank worked out at 30 mpg it has now gone down to 100 to half a tank. Anyone got any idea what could cause this thanks.

hole in the tank or it's shrunk!!!!

When was it last serviced? Have you noticed anything different about the characteristics of the engine such as less power, less responsiveness, unsteady idle, more exhaust smoke etc? First thing I would be doing is cracking the bleed bolt on top of the fuel filter housing and checking that you have a good clean flow of diesel without air. Next thing would be a full engine service. New oil, oil filter, fuel filter and air filter. Also check intercooler and air intake hoses for leaks or internal collapse etc.

-Tom

Thanks will do

Intercooler pipes should be ok just fitted silcone hoses