dfinnegan

My car has been running normal, to low, temps all through the spring and summer.

Either the connection to the sensor was bad and got better after I fiddled with it or the thermostat was going out at the time. It subsequently failed and was replaced in March (early spring here).

I'm betting it was the thermostat.

911URGE

Thanks for the update. Ive been searching, reading and testing this last week. I am experiencing similar issues as you did. I went ahead and replaced the fan switch but have not driven the car yet. I suspect the thermostat may need to be replaced as well.

dfinnegan

I replaced just the thermostat insert.

Get plenty of rocker panel clips. They are old and brittle. I only broke a few, but replaced them all.

You may want to get some rubber oil hose bits, as well. Mine were leaking and I didn't have a replacement on hand. Tightening the jubilee clip helped, but these will get replaced with the next oil change.

My rocker panel rubber gaskets are also quite brittle. I have replacements and these will go on with the new hose pieces.

911URGE

As a follow up to my previous post I drove the car today in 95F heat and it barely went above the first line (8 oclock position) while driving in city traffic. Got it back home and let it idle in the garage and confirmed both low and high speed fans are now cycling automatically. High speed fan kicks in a hair above 9 oclock and drops the temp to just above 8 oclock position. I think the oil cooler fan switch was the ticket for me. Thermostat is opening as I can hear the oil and the right front fender gets quite hot.

As a side note my CCU threw a fault code #42 - Oil cooler fan motor prior to the repair. I cleared the code and it has not returned since the new switch was installed. I suspect the switch was failing but not enough that the CCU saw that as an issue but enough that the fans would not cycle.