finally got the engine to keep cool

[KCPSG]

well as the post says, I finally have cooler engine temps. Yesterday I installed a new thermo switch on the front oil cooler, and wow what a difference. The temps were running quite a bit higher before I installed the new thermo switch (around 250*) now I can't get the temps to go above 210* - 215* and I ran it hard and for a long time today trying to see if the temps would finally creep up on me.

The part I used is a BMW part # its 61-31-1-364-273

Wayne mentions this part in his 101 projects book, for those that haven't done this yet I highly recommend it.

BTW the temps today as I was testing the new thermo switch are 95* w/almost 90% humidity...they say the heat Index is 105*

[87coupe]

Nice! Thanks for the info

[dd74]

Originally posted by KCPSG
BTW the temps today as I was testing the new thermo switch are 95* w/almost 90% humidity...they say the heat Index is 105*

Ah, I remember it well. I used to spend my summers in Lafayette. My folks tell me the parish is huge compared to what it used to be fifteen or so years ago.

Anyway, this is great news, Phil. By thermo switch, you're talking about the switch for the fan that adapts to the front of the cooler, right?

[87coupe]

Wait, I thought this was the switch to open the flow to the oil cooler?

[KCPSG]

Its the one on top of the front oil cooler that runs the fan, it took me about 4 hours to take the cooler out and replace the switch and remount w/new insulating foam (around the edge of the cooler)
BTW the new switch is a 2 prong switch so you need to add a ground to one side and cut off the other side, (+) and add a female bayonette type connector...AFAIK it didn't matter which side was (+) or (-) and the fan kicks on exactly @ 9 O'clock or 210*.

[bigchillcar]

this is the bmw switch that turns on the fan at 210 versus 240 for the porsche version.
ryan

[KCPSG]

here is the page the fan switch is located on...its listed 1/2 way down the page under Auxiliary fan switches http://www.pelicanparts.com/BMW/catalog/shopcart/BE30/POR_BE30_electr_pg4.htm#item24 the switch goes for $11.35

[87coupe]

Can someone explain how the flow to the oil cooler is triggered? Or is it always flowing? On my 87 it doesn't seem like it flows oil to the cooler until it has reached a certain temp? If this is the case, is there a mod / part swap to run the cooler at a lower temp? Thanks in advance

[bigchillcar]

aux oil coolers have aux thermostats, which are located in the rear fenderwell area. i believe that they open on your car at about 190 degrees. your car's primary engine oil cooler has a thermostat that opens to allow oil to enter it at 180 degrees, so when the oil begins to get even a little hotter the aux thermostat opens and sends oil up to the aux oil cooler for extra protection.
ryan

[87coupe]

Thanks Ryan. Mine does seem to open at a little higher temp than you describe - more like 210'ish, just before 9 o'clock. Ideally, I would like to see it run flow to the cooler a little earlier, hence my question about modifying. Thanks again

[bigchillcar]

brandon,
i checked in a manual to confirm and find that the aux thermostat is actually supposed to open also at '182 degrees'. one way to determine if you have a problem with your aux thermostat is to 'feel' the oil cooler at say 170 degrees..it should still be cool..check it again at 180, then 190, etc. until it starts to get warm..that should give you an idea of when it's opening up (when aux cooler starts getting warm all of a sudden).
ryan