I completed my annual inspection a few days ago
New engine oil
New 50/50 antifreeze/water
New drive shaft and ball bearings on cog belt PSRU. These PSRU parts I
damaged myself when dismounting from the engine.
I have not flown the aircraft yet since inspection, prolounged ground
running failed to raise the engine oil and antifreeze temperatures above
150F-155F. OAT about 32F to 35F. These engine temperatures are not
standard for my 1986 engine, which would easily  reach 180F after a few
minutes of ground running at 3000 rpm.
A trusted friend has suggested that my old coolant was much too rich in
antifreeze due to the water content having evaporated over time, but
please advise
Yvon