My Pete rebuild

[Nostalgic]

(06-10-2022 )marek4792 Wrote:  I mentioned something about the thermostats briefly awhile back, with STOCK files with 235 thermostats it wasnt uncommon to see trucks break 250°F+ especially KWs and Petes when pulling long grades foot to the floor. I think one of the main factors is the condensation of the oil if the temperature is too low. Hitting 240-250 on a stock file doesn't seem normal even if the engine is completely fine, but yet alot of trucks do.

I don't think those temps "hurt" the oil as much as they increase oxidation and shorten it's life. I haven't pulled any samples before or after changing the t-stat for proof, so just my speculation. I'll probably pull one at next OCI to get a baseline going forward. As an added benefit, the cooler oil temps give me about 3-4 oil psi increase @ 1800 rpm. Was strange to see oil pressure climb a little during a higher rpm pull instead of staying flat to 1-2 psi drop as the oil temp climbed before.