Good Stuff Traz.
Continuing further with our 'LeSabre longevity' discussion, I would fall short if I did not add something that I feel is quite substantial toward 3.8L longevity. I prefer for the cooling fans to come on at a much lower temperature than what is setup from the factory. The problem is, by default, the P04 PCM doe not have control of the cooling fans. Instead they are controlled the BCM. I change it to where the PCM tells the BCM to allow the PCM to control the cooling fans. This way, I can set the cooling fans to run at the temperatures that make more sense to me. How significant is it? I think it's a major risk as to how excessively high that I've seen the coolant temperatures reach before the BCM commands the cooling fans on. Before I switched over to PCM control. I could sometimes see the coolant temperatures reach 210 degrees F before the first fan was commanded on.
Now that the PCM is in control on all of my LeSabre's...
- I have Fan-1 set to turn on at 89.5 deg C (193.1 F) then off at 87.5 deg C (189.5 F)
- I have Fan-2 set to turn on at 92 deg C (197.6 F) then off at 90 deg C (194 F)
- Then both fans off when the car is above 45mph. then resume temperature control below 40mph.
Regardless of the GM 3.8L being such a durable engine, I think permitting any engine coolant temperatures to rise so high is just not a good thing to do. And subsequentially helps the 4T65e to last longer (in combination with implementing the changes that Traz and myself have highlighted thus far in this discussion on 4T65e longevity).
Also, I appreciate the very helpful corrosion prevention measures offered by the folks who live in the northern states. An area that I can learn from you folks since we don't have much corrosion here in the south.