I recently picked up another project car, anyone want to chime in on causes of this amount of sludge. 2003 Tdi Vw with 148k miles, turbo failed due to clogged supply line go figure! Previouse owner swears he did 10k oil change full synth. The car was only driven in the summer, parked each winter. No information on brand or diesel specific oil, or if it was changed before parking for the winter.