Perkins 4-108 hot-cold oil level

[shanegeard]

I'm interested in knowing from other operators of Perkins 4-108 engines what sump oil difference they have between hot and cold. I'm getting a full reading on stone cold and the level goes to the bottom mark when hot. This is about a litre of oil difference. The really interesting part is that it takes about 3 days sitting idle to work its way back to the full mark.
If I set the oil level to full when hot then the level just goes off the top and up the dipstick after 3 days, making it unreadable.

[NCSailor]

Following

[a64pilot]

Do you check it twice? Some engines can pull a vacuum on the tube itself drawing oil up the tube and giving a false reading, for those you have to recheck.
Only other possibility is the drainback opening in the head are clogged and the area under the valve cover is full.
I have never seen that however, but guess it’s possible?

[shanegeard]

Originally Posted by a64pilot

Do you check it twice? Some engines can pull a vacuum on the tube itself drawing oil up the tube and giving a false reading, for those you have to recheck.
Only other possibility is the drainback opening in the head are clogged and the area under the valve cover is full.
I have never seen that however, but guess it’s possible?

Thanks a64pilot. Yes, my dipstick observations are the result of months of checking and rechecking. I've only had the boat since last December, so I'm not sure what is normal for this engine.
The idea of a clogged drain is intriguing.

[a64pilot]

Just try leaving the dip stick out for awhile to see if it makes a difference.
I can’t imagine oil is being trapped in the head and taking three days to drain back.