granby300E

Hi All, I have a 1991 300E 4Matic with 112k miles. I have noticed oil drips in my garage and my local shop diagnosed it coming from the oil level sensor and head gasket. The cost to repair both right now is not feasible, but they felt the sensor was the main culprit. I plan to have the sensor replaced, but am wondering if the sensor itself is prone to leaking or if it might just be the o-rings that are not sealing. It seems to be functioning correctly as the warning light has come on when the oil level drops below the mid-point on the dipstick. Can anyone advise me on this? Thanks, Richard

PhantomLord

I had similar oil leak from oil level sensor, it usually leaked when engine was hot. Local shop replaced complete sensor.

doxland

I changed a sensor because it was leaking through the electrical connection, not the gasket.
I mean where the wire penetrates the device. Pretty easy job, 20 minutes.

mb_s320amg

HI, Sorry opening very old topic. I have 1998 s320, and notice oil leak from the same place (oil level sensor). When you said it took 20 min., is that mean you didn't have to remove the whole pan,(I am assuming) I see on mine there are two 10mm bolt, Do you think I can replace from there ? Price of O ring is chipper than sensor, and very tempting not to buy sensor.
I am planning to buy new sensor, I don't want to go there twice.
Also I just have change oil, So I guess I have to wait till next oil or I can drain and reuse same oil?
Thanks for your help in advance.

Cali300E

As I recall the sensor is above the oil level, so you don't have to drain the pan. Just loosen the bolts a little and wiggle the sensor loose, if oil starts dribbling out then I'm wrong If you look at a new sensor you'll see that it hangs down inside the pan (that is, it doesn't pull straight out), so as I recall you tilt it as you remove it . It makes sense once you start fiddling, and it's an easy job.