Westerbeke w52 yellow tint in oil inside valve cover

[kevins]

I have a westerbeke w52 with 1300 hours on a complete rebuild. I took off the valve cover to check the clearance of the rocker arms/lifters.
Upon taking the valve cover off, I noticed there is a yellow tint in the oil on the back half of the valve cover. The yellow tinted oil gets progressively darker as it nears the back end of the valve cover near piston 4. The valve cover and the residue oil near piston one is as expected, grayish blackish oil. But as you approach piston 4 the yellow tint sets in.

The antifreeze is green, the oil was changed 6 hours ago.
I have attached pictures to show both the valve cover and the items under the vavle cover

Any suggestions on what the yellow color is would be greatly appreciated.

Thanks
Kevin

[kmacdonald]

Antifreeze.

[a64pilot]

Does it wash off?
It sure looks like dye penetrant to me.

[kevins]

Yes I can wash it off. It appears to be mixed in with the oil. It wipes off.

Just to be clear the engine head is painted yellow. That is the yellow shown on the head outside of the valve cover area. The inside of the valve cover was not painted. Just the head outside of the valve cover area.

I saw that, but maybe somehow the paint got in there. This was 5 years ago when the engine was painted.

[model 10]

The yellow area is where the temp is correct. The gray area is sludge and where it's too cool.

[kmacdonald]

Send it out for an oil analysis. No need to guess at it.

[kevins]

Can you recommend a place to analyze the oil? We are in South Carolina.

[kevins]

So maybe my lifters need adjusted. I was doing that when I noticed this issue. I will check them out again, clean the yellow off and check again in 30 hours or so.

[thruska]

Dyi oil anal ysis... touch , smell , taste... dont step in it... go for lunch.
Try running your engine with valve cover off to see if oil is passing thru all the places it needs to ...
Gray oil is sign of coolant/water mixed in oil.
That yellow crap is just weird. If it wipes off its not likely paint imo .
Whats the oil on the dipstick look like ?
In photo your paint on engine looks green..
Good luck!

[kmacdonald]

Did you have the engine worked on by someone else recently?

[fuentes]

Perhaps a little water condensate from humid weather? I have an old tractor that I find yellow color with the oil on the cap of the transmission. It has been driving me nuts for years.

[kevins]

No, the engine was not worked on by anyone else. In fact it sat for about 1 year, then we started traveling again in May. Have put 100 hours on the engine since May.

[kevins]

Condensation is an option. Sitting for one year in FL.

[jimbunyard]

While the color rendition of pictures on a screen is notoriously inaccurate, that certainly doesn't look like any kind of emulsified oil I've ever seen; usually the color is like creamy coffee and the texture is something akin to runny mayonnaise.


As for what it actually is, I'm at a loss. Is the stuff hard or soft? Is it soluble in water or oil? Have you had any noticeable loss in coolant?


If the engine starts easily and runs well, if there is a problem, you might just have to wait until it manifests itself more clearly.

[a64pilot]

For those that have done non destructive testing, it’s looks exactly like dye penetrant.
I’m not saying that is what it is, but if I had a black light around I’d like to see if it fluoresced, glowed.