Oil leaks from tappet cover 914UL-300hours

Roger Lee wrote:

Leaks are not always where the oil ends up. The higher pressure and or high flow air will move a drop or two of oil around and make it look like it came from somewhere else. If I see oil on the back of the engine I start at the front and start my check or tightening.

Here is a leak detection tip that works very well and can find the minutest leak.

First clean the engine of oil, dirt or fluids. Let it dry. Then buy some Desenex foot powder spray. It is just a spray on white powder and sticks to the engine. Spray all the areas of any suspected leak or spray the entire engine oil fittings, seams and joints. Now go fly for an hour or so. When you come back you will have a huge red flag staring you in the face where even the tiniest of leaks happened. Even ones that aren't really visible to the eye without the white powder.

I was convinced that I had 3 rocker covers leaking, enough to need wiping down every few hours of operation. Each time i carefully checked for where the oil was originating from and even with wiping down the pushrod tubes with my fingers, they always came up dry and the only place there is any evidence of oil is directly on the bottom of the rocker covers. I tried many things to stop these leaks.

I then tried the above advice from Roger with spraying athletes foot powder around suspect areas. I was immediately surprised to see oil weeping from out of 3 of the push rod tubes. Thanks for the tip Roger, I can now focus on the actual leaks...

Hi Murray

Leaking push rod tubes?  If these are leaking at the top where they are installed with Loctite you might have a bigger problem.  That could be a sign of engine overheating.  Perhaps sometime in the past it ran hot on the coolant?  

Cheers