As a recent and current 650ci (N62) and 750li (N63) owner I have fast become aware of the ongoing valve stem, piston ring, and the other well documented issues (and ongoing class action lawsuits) surrounding these engines. I was fortunate enough to just have to recently had the engine in my 750 replaced under warranty and want to take precautions necessary to protect and or prevent the premature failure of this new warranty. During my research I came across some interesting opinions with regards to installing a low temperature thermostat on both of my vehicle. ”Apparently” the OEM is a 105 C theem which is only present on the BMW V8 motors in order to maximize overall fuel econ while it is theorized this higher than industry average temperature is the primary culprit for the advanced deformation of seals, rings, hoses, gaskets and even transmissions.
Apparently fuel economy will take a “slight“ hit but the overall health of the engine internals will benefit from the cooler running thermostat. I would consider myself a driveway mechanic at best but somewhat do relate to the logic of some of the materials I have read but nonetheless would greatly appreciate any input from those who may have already proceeded with this modification as well as any advice from far more educated mechanics than myself. NOTE the thermostats I researched on EBay etc claim no codes will be thrown???