[click to enlarge]
crankshaft position sensor is very important to proper engine operation. If
it fails or works intermittently, the engine will either barely run or not
start at all. Fortunately, the engine’s main computer (DME) will indicate
whether or not there are problems with the crankshaft position sensor. (See
Project 28 for more details on reading fuel injection error codes.)
The sensor itself is easy to reach and replace. On some
models, however, the wire harness that connects the sensor to the rest of
the car is hidden underneath the intake manifold. Remove the intake manifold
to replace the sensor. Or, you may be able to access it by reaching
underneath the manifold—if you have skinny arms—and removing the oil filter
housing first. Either way, getting to the harness connector is not easy.
To replace the sensor, unscrew the 5-millimeter Allen
bolt that attaches the sensor to the engine case. The sensor will always be
mounted facing the toothed degree wheel attached to the front of the
crankshaft. Depending upon which car you have, you may need to remove the
radiator fan (see our radiator replacement article).
Wire harness routing varies widely from car to car. On
the E36 six-cylinder models, the harness is routed through a plastic cover
and then underneath the intake manifold. Disconnect the wire harness from
the engine, and replace the sensor. Be sure to route the new harness along
the same path as the old harness.
On some E30 cars (1984–1987) 325e/s models, there are
two sensors that read the toothed crankshaft wheel. When replacing these,
double-check that you don’t accidentally switch the two sensor plugs. They
should be color-coded to match their receptacle plugs.
If you would like to see
more technical articles like this one, please continue to support Pelican
Parts with all your parts needs. If you like what you see here, then
please visit our online BMW catalog and
help support the collection and creating of new and informative technical articles like
this one. Your continued support directly
affects the expansion and existence of this site and technical articles
like this one. As always, if you have any questions or comments
about this helpful article, please drop us a line.