Testing M103 Oil pressure with a mechanical oil pressure gauge

In my last update, I had ruled out the sender unit when it came to the low oil pressure readings on my 300SE.   My intention had been to take the car to a mechanic to test it on a mechanical oil pressure gauge.   Two things changed that.    Firstly, my area of Sydney went into lock down.   Secondly, most mechanics are on holidays until after the new year.   I therefore purchased my own mechanical oil pressure gauge off eBay.

I hooked up the gauge and sadly the results were much the same as the dashboard gauge.   The mechanical oil pressure gauge I purchased has a number of fittings and one of them was correct for the M103.   It also had a quite useful elbow connector.

It is much easier to attach it with the oil filter removed.   Don’t make the same mistake I did, and not attach the filter properly!  You’ll end up with a lot of oil on the floor very quickly.

As can be seen by the readings below, they are not what they should be.    The first one is immediately after start up, and the second is after a couple of minutes of running.

As can be seen from the next photo, there is oil at the top of the engine, so something is working properly.

I also made a short video about taking these readings.   Still not very good at this video thing, as the gauge itself is not readable, and when looking at the senders, they are out of picture, but plenty of room for improvement.

As I mentioned on the video, I will take the car down to my workshop and remove the cam cover.   From there, I should be able to inspect if the oiler tube has come loose.   This was suggested to me on a thread in the ozBenz forum.