Hi Scotty, I recently had a V8 (N63TU) engine replaced on my 2013 BMW 650, these engines are known to run hot, the factory thermostat is 105C (220F) for emission and MPG reasons I assume, and I want to make the engine run cooler to prolong gasket and seal life (valve stem seals and head gaskets are common issue on this engine), and from my research I have found 2 solutions

  1. Replace the 105C thermostat with a 90C thermostat: This option is not DIY friendly as well cost alot more than option 2.

  2. Replace the oil cooler valve so that it is open all the time, essentially the oil will go to the oil cooler all the time as long as the car is running, this is an easy job since its right beside the oil filter housing, however my concern is that I live in Canada and the winter could be -10C to -25C, with oil being cooled all the time I would imagine it would take awhile for the engine to reach operating temperature, I am ok making longer drives but I am worried that running the car at low temp at prolonged period would cause additional wear to the engine even if I driving moderately (under 2000RPM).

What are your thoughts?

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Scotty Kilmer
Scotty Kilmer


thermostat, oil cooler change can ruin the engine in the winter there

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