slightly rough w108

[Californian SE]

hey guys,

so im at the lights today, and i notice the w108 (280SE) is running a tad rouch. i get home, in park its fine, but in reverse or drive, when going slowly i get a creaky noise from the rear diff. and when idling its just a bit too chuggy for my liking. and starting is still a huge problem, its as if its flooding, but it isnt because it starts quicker with my foot on the gas. im lost. and i read something in the merc club mag today about new plugs and lines, with clean, close fittings can help reduce the fuel consumption (mine seems to be very high, about 250 miles to a tank?)

two other problems (i think may be related) there is a noise which is echoed in the exhaust, like a compression leak, or "whoosh" of air, at a certain Rev Mark through each gear (you hear it four times before reaching 60) and its getting louder. especially up hills. could it be a leak in the master cylinder?
and the brake fluid seems to run out quite quickly, i topped it up a month ao and it emptied last week, so i topped it up again, maybe there was air in the system? sorry bout all the points. but on the good side, thats all thats wrong with the car! haha.

any info is appreciated, cheers, Luke

[Mike D]

Might be all part of the same problem. Pull and block the vacuum line to the brake booster to see if it solves the idle problem.

Obviously I cant advise you to drive the car with the line blocked to see if it resolves the "whoosh" problem. That might just create a "WHOA" problem at 60 mph when that delivery truck pulls out in front of you!

The brake fluid has to be going somewhere. Check the calipers and all the lines for leaks. If they are all dry then it has to be seeping into the booster. Brake fluid can eat the booster up fairly quickly. Pull the master cylinder forward a touch to see if there is leakage on the rear of it.