From digest.v7.n351 Mon Sep 29 21:20:58 1997
From: James Muskopf <jmuskopf_at_vt.edu>
Date: Mon, 29 Sep 1997 19:11:08 -0400
Subject: Oil leak near temp sender and pressure switch
Yes, the leak you are experiencing is probably from the pressure sender
switch and/or the temp sender. It could be either, but I believe that the
pressure switch is much cheaper than the temp sender. Even though the temp
sender is completely sealed from the oil, there may be a small crack in the
protruding brass part. It will leak. Unplug the two connectors and clean
them well. Clean the switches and the surrounding area. Use brake cleaner
or carb cleaner. Start the car with the hood up and watch the switch
bodies. It should only take about 20 seconds or so to see if there is oil
coming from either or both of the switch bodies. If you're not sure, shut
the engine off and swab each switch individually with a Q-tip.
There are also two lines where the oil filer housing connects to the oil
cooler. Clean around these fittings and watch them also for leaks. These
are _usually_ very reliable. If one is leaking, you can get by for a short
while by cracking the offending fitting open and retightening. They are
very tight! Get new sealing washers for these if you ever take them apart
or if they leak.
Those switches can leak badly enough to spew a whole quart after 300 miles.
I've only seen the fittings leak a tiny amount.
1975 530i/3.4L Motronic
[ Help ]