My '85 245DL fuel pumps made a whine-grinding sound that I couldn't fix, and the car was a bit hard to start and ran rough. First I replaced the filter, then the intank pump and filter/sock, then a succession of generic main pumps, and finally put in a BOSCH unit ($$). None of these new parts stopped my whining-groaning sound and my car dropped from 24mpg to 18mpg on the highway. Yesterday I put in a new OEM fuel pressure regulator(about $50.USD), and the problem stopped! :banghead: Should have checked fuel pressure first, eh? I'll post here again as soon as I run a tank of gas out to see if my MPG goes up too.

I have ran a tank of gas with the new fuel pressure regulator installed. RESULTS: now getting over 24MPG (0ver 15% increase) and the pumps sound great. :smile: