It has been months and now all 3 of the additional gauges I installed in the center console are fully operational. The holdup was the temp sender. Lets look at the entire setup.
I wanted a very stock look under the hood. I didn’t want to use any traditional aftermarket solutions. I found a 3 port water neck from an E30 318i. This bolted right in replacing the standard 1 port water neck in the 2002. I had replaced the 1 port water neck with a 2 port water neck from a Tii or 320i so I could have a temp switch for the electric fan in the water neck. So now I got a 3 port water neck in place of the 2 port. The port sizes are 2 M14 x 1.5 and 1 M12 x 1.5. The stock temp sender is M14 x 1.5 and the BMW temp switch is an M14 x 1.5 so I needed a VDO temp sender in the M12 x 1.5 size. Easy right? Wrong. VDO only listed one temp sender in M12 x 1.5 size but its a 300 degree sender. Well VDO doesn’t make a 300 degree temp gauge anymore! The new temp gauges are 250 degree. So I tried to get a different size sender and adapters. That didn’t work because the adapters either were for oil pressure and a temp sender wouldn’t fit through them or the VDO sender was too big to fit through the adapter. So that didn’t work. My next thought was to take the water neck to a machine shop and have it drilled out and tapped to an M14 x 1.5 port which has a multitude of VDO senders available. Then some on the BMW2002FAQ contacted me and said they found a VDO sender that was M12 x 1.5! I looked and yes it was there, but only in a few places and it wasn’t even in the VDO catalog!!! I did a google search and it didn’t show up, in fact Summit Racing where I bought it from had zero specs, just a VDO part number, again which wasn’t in the VDO catalog. What? So I googled some more and found that VDO just released this a few weeks ago and it was done for Chevy LSx engines with a M12 x 1.5 port in the head and these guys have been asking VDO for years to make a temp sensor that would allow a simple addition of a VDO temp gauge.
Now that I have the proper sender, install was a breeze. I had already run a wire from the center console to the engine bay. I just had to put a connector on it, heat wrap the end and connect it. Once I did that and checked for leaks, the temp jumped right up and its up and running!!!