E21 cooling, aux fan and engine fan information

[throwback320]

I needed to post this because there are so many different answers out there on this subject.

I live in Southern California and my 1982 E21(US Model) was always running hot in bumper to bumper traffic, and I would stress as my temp guage would climb over the 3/4 mark. Well, I recently swapped my old radiator for a new one (copper core all metal), ordered a fan shroud, and a new 82% aux fan switch. I discovered that even though they sell the shroud stating it will work on a 1980-83 E21 you will need to swap your 400MM engine fan with the 1976-79 360MM engine fan as the 400MM will not clear the shroud. You will not need to change your water pump pulley (holes line up) to do this change and the support plate in which goes in front of the fan will also fit on the 360MM fan. The shroud set up has made a huge difference in cooling the radiator. (Now the aux fan). I let the car sit in the garage with the motor running after a drive and the guage started to go over the 1/2 mark at just about half way to 3/4 the aux fan kicked in as it should. The A/C does not need to be on for the aux fan to work. The aux fan will kick in when the switch (in my case 82% ) reaches it's limit and will cool the radiator to normal temp then shut off when done.

There are only so many of us with these cars now, and I hope this post helps somebody else out there with these questions.

[Jeroen]

Now that is useful info indeed, I added your report to the FAQ section right away. And above all I'm glad you got your problems solved.

Sadly BMW is trying to generalize the use of parts more and more to reduce their stocks, like saying the fan shroud fits (or was used on) all 4 cylinder cars. We have already seen worse issues where parts definitely do not fit without changing many other parts. I guess their approach is that you can make things work in the end, but this approach combined with an absolute explosion of BMW's parts prices causes that many people start to search for alternatives.