This old truck shows a bit of condensed water in the oil. The head and gasket are fine, the compression is good (don't remember the numbers off hand). The cooling system has a new radiator, thermostat, hoses, heater core and doesn't leak. The only source seems to be condensation after setting a day or two without being driven. It dissipates after reaching operating temperature and being driven.

My question is: Do you folks agree with me and is there any danger of engine damage?

Thanks for your help
Mac

 

Some condensation is normal. Things to double check;

While the engine is idling, pull the PCV valve out. Put your finger over the inlet, it should suck on your finger. The PCV valve is what helps suck that condensation out of the engine.

Make sure the engine warms up fully. If the thermostat is stuck open, it will not warm up properly and it will aggravate the condensation. You will have other signs, as in the temp gauge does not come up when it's cold outside, and your heat is marginal in the cab. A very low thermostat will also aggravate this, you can buy 160 degree thermostats they are too low a temperature. I would not go below 180.

If you go on short trips in the winter, some condensation is unavoidable.

 

It is difficult to imagine, but it may take ~20+ minutes of steady driving for the crankcase oil to come up to temperature so that condensation may evaporate. Short trips, especially during cold winter are not good for the engine.

 

I have a fairly short commute and figured this one out. A 4.9 is a big old chunk of cast iron and takes a LONG time to get up to temperature. The oil has to come up to above the boiling temperature for the water to boil out and THEN run a bit to get the moisture out. When it does turn to vapor, the PCV system draws it into the intake and it is burned off through combustion. My commute did not let that happen. The evidence I saw looked like whitish vaseline on the bottom of the oil cap. My solution was to be sure once a week to take the truck for a much longer drive somewhere that included some interstate driving. I never saw the signs of condensation again. I also made sure I had the proper 195 degree thermostat too.

 

I've had new thermostats DOA. Are you using a 195 t-stat?

If everything else checks out (thermostat being prime suspect), bump up your timing and lean the fuel mixture! That will get your temps up.

Also, my old six was pretty cold-blooded in general, so be sure to give her an Italian tune up time and again.