Oil level slowly going down

[ColeHarmening]

Hello all,

My oil level is going down on the dipstick after running my engine for long hours. My question is do I have a slow oil leak that somehow I am not seeing in the engine compartment? or is this just normal oil consumption of an old engine?

I have been running my A4 at normal - high cruising speeds for fishing for an average of 10 - 15 hours a week. I am having to top off the dipstick every 15 hours or so. It slowly creeps down the dipstick. 15 hours ago I was at the full mark. Now I am at about the 5/6ths full mark. 15 hours later I will probably by in the 2/3rds full mark. Is it normal to burn oil at this rate? I have extensively checked in my engine compartment/under the block and in the bilge for oil but can't really notice anything leaking.

[Dave Neptune]

Oil consumption can vary as to the tune of the engine as well as wear in an "old" engine.

If you are not seeing the oil in the bilge it is getting burned in the engine. In a flathead such as these the valve train has little influence on oil consumption like an "overhead" engine as gravity assists the flathead and works against the overhead. Most of the oil loss in the A-4 will be past the rings due to wear, not a bad thing as long as you don't run out of oil.

Another factor is the ignition timing being to advanced will also increase the oil consumption and cause rough running.

How do the plugs look? Is the C-advance working freely? Any fumes emanating into the cabin? Have you set the timing or adjusted the points if still equipped with them?

My ole A-4 used oil at close to that rate and I ran it for 30+ years like that and never an issue. I did mitigate the problem with a PCV valve a more modern and far superior to the slash tube. The PCV was not invented when the A-4 was designed and is a good addition. Are you having any other issues as far as how the engine is running?

Dave Neptune

[ColeHarmening]

Thanks for the info Dave,

No I am not having any other running issues. Yes my fume detector seems to be going off more frequently now but other then that I can’t visibly smell more fumes. I suppose I will just need to always carry a good amount of extra oil while out cruising.