AeroVee assembly oil leak and oil pressure spike

Following AeroVee 2.1 Instruction manual on my Onex project I prepared the engine for first start by “Priming the Engine and Setting Oil Level.”(Page 60). I operated the starter and observed oil pressure indication on my Dynon spike into the red line. I stopped cranking the engine and discovered a large quantity of oil dripping onto my oil pan. Unable to determine the source of the oil leak, I removed the engine from the mount and took the rear apart down to the Oil Seal. Oil was present around the gland nut that I removed. The oil seal appeared to be installed correctly. I removed the oil seal and ordered a new one.

Sonex tech has offered suggestions and I followed up by checking the oil sender and it is accurate. Re-checked the oil pressure relief plungers and they are installed correctly. Crankcase breather tube is clear. I am getting ready to reassemble the engine and test it on a stand as suggested by Sonex. I would appreciate any suggestions as to the cause of the oil leak and the spike in oil pressure before I start reassembly.

Welcome to the forum! If it’s truly spiking, possible causes are blockage in a galley or the plungers sticking. I’d make sure the plungers are free.

Also, what was your oil temperature when you cranked it?

Also check out this thread:

In particular, look at Mike’s post from Mon Jul 06, 2015 9:59 pm.

Make sure the drain behind the seal is not blocked. Too much RTV is bad.