ok my boat 454 mpi procharged engine has an issue with mily oil coming out of the breather I run synethic 20/50 either royal purple or mobil one 15/50. but for the heck of it I bought 20/50 conventional oil just the cheap stuff in the blue 5 qt jug and took it out to the lake twice maybe 10 total hours and for some reason I got no oil at all going into the puke tank I installed. . then today i drained it out and went back to mobil one and sure enough it spit out a lil bit its never all that much just a few ounces at the most .any ideas what I should do or maybe a thicker oil ? I prefer full synethic oil but I woul like to hear anyones input on this thanks

If your oil color is milkly looking, like coffee with creame in it, you may have water getting into your block. Once you go synthetic, you should never switch back to regular oil. Synthetic swells seals more than regular oil. Once you go back, you could be creating water leak paths into your block. Also, you could start having oil leaks.

its condensation I only ran the cheap oil to clean out the motor for a few hours then put the synethic right back in I have always done that with no problems.Im just curious if anyone has any idea why regular oil doesnt make the condensation like the synethic does thanks or any other input woul be great

Built engine with synthetic oil ran for several years with no oil leaks, switched to Dino about 1.5 years ago, now have rear main leaking. Do you think switching back to Full Synthetic will bring back the sealing I once had?

I would bet the synthetic oils run cooler oil temps and the condensation is not burning off. It might only be a 10* difference, but you might be right on the edge of where it burns off.

I agree with griff.

You can change back and forth from synthetic to petroleum all you want. Modern day synthetics have the same affect on seals as a petroleum oil.

Case at point, synthetic/petroleum blended oil.

In the real early days of synthetics this was some what of an issue, not today.

Ken

I would say the synthetic is "running cooler" because it is not transfering the heat as quick as petroleum.

Ken

Check your intercooler it's not the oil. Presure test it.

the intercooler could do that ? How?? and how do i preasure test it?