I was getting ready to do my weekly routine of emptying the PCV catch can on my 4R and came across this.... Normally the oil is jet black, but this caused some alarms to me. Fearing a blown head gasket, I immediately checked the oil dipstick and oil filler cap but they were fine. I changed the oil last week switching from M1 5w-30 to 10w-30 to experiement with gas mileage and performance. Normally when I clean the can, I will just empty the oil, spray a little bit of brake clean, and wipe it with a clean shop towel then reinstall. What do you guys think is causing it to look like this? Could it possibly be from the difference in oil?

 

Condensation. Take a look at the underside of the oil fill cap and you'll probably see the same thing.

It takes a normally driven vehicle engine 35 miles to get warm enough to burn all the condensation out of it.

The glass PCV catchcan / container doesn't get nearly as warm as the engine doe's.

 

Yup, mine does the same, moisture in the air or condensation in the catch can will do that.

 

Thanks for your replies guys. I'm glad to know it's possibly condensation, but why would it just now start being so murky colored? Before the oil change it was just plain black, thick but still black. The more I thought about it though... I did switch over to 10w-30, but I also added the little tube to keep the air from sucking the oils directly from the exit allowing the oil to drain downwards first then the left over fumes to be inhaled only by the engine. I may take the tube off just to see if it makes any differences.

 

Rain, cold temps, etc can all cause this to happen. I assume the season is changing down there too. This summer it never happened to me, but now that winter is kicking in, it's just how it is.

 

Ahhh yes I see now (slaps self on forehead)... I didn't take that into account as I only put it on sometime back in the spring or summer. Thanks Oly.

 

Is that on the 2.7 too?

 

Only if you have the PCV catchcan mod, which is something that never comes from the factory

The oil inside the engine is not affected.