Can Synthetic oil evaporate and cause oil film

[OilUzer]

Can Synthetic oil evaporate and cause oil film?

I am seeing this oil film near the engine oil filler cap, PCV valve (which is right under the cap) and surrounding area after changing the oil from dino to synthetic.

i am %100 sure there was no oil film prior to using the synthetic oil as i check stuff once a week ... unless it is a coincidence (very unlikely imho) and something else is failing (PCV valve?), seems like the synthetic oil is doing something to cause this. The oil film is getting bigger it is not really greasy/oily but looks like a cleaner or shinier patch than other areas and it is very slowly growing ...

do you think that synthetic oil maybe causing this? I will try to attach a picture.
Thank you!

some background info:

2014 Hyundai Tuscon
2.4 L DI engine - 4 Cyl.
58000 miles

Car runs great! No noise or any other issues.
Always use Chevron 92 or Shell 92 octane gas.

Owner's manual Specifies:
5.28 US Quart 5W-20 (better fuel economy) or 5W-30 or 10W-30 (if 5W-20 not available in your country)
Temp in my area is mild: Mostly in 40-65F range. This year few cold days 25F ... and few hot days 92F

Owner's manual OCI:
7500 miles or 3750 miles under severe conditions which does not apply to this car.

My OCI: In the past i have changed the oil (dino) every 3500-4500 miles max.
based on color, feel and smell (nothing scientific ... lol)
was thinking of pushing to 6500 miles with the synthetic oil.

last oil change:
Pennzoil Platinum Full Synthetic d1g2 5W-30
First time using full synthetic on this car.

All previous oil changes:
chevron supreme 5W-30 from Costco and couple of times chevron supreme 10W-30 in the summer.
Main reason for using chevron supreme: I had many cases of chevron supreme in the garage (only 2 or 3 cases left) and it has been a good oil. i use it on 2 other older cars with no issues. one car has over 300K miles and other almost 200K miles.
Found PP almost same price as chevron supreme and decided to give it a try.
Based on what i have read, it (PP d1g2) is a better oil for DI, LSPI, Moly the jolly, etc.
Never done UOA. My UOA is color, fell & smell test.

burning oil:
2450 miles after oil change (PP) i added ~8 fl. oz. - some oil was burned.
with Chevron supreme it burned ~4-6 fl. oz. in 3000 miles. a little less than PP.

Oil Color:
not sure if the color matters but just FYI:
after 2500 miles with PP, oil is light honey color (darker amber?). i am very impressed with the color if it means anything.
with chevron supreme it would get much darker after 200-400 miles!

another FYI:
car sounds the same to me but i am not the main driver. few weeks after the oil (PP) change we were on freeway and my
wife just randomly asked me "what did you do to the car ... it sounds quiet". i was very surprised and asked are you sure?
she said well you always want to know if something feels or sound different so i am telling you ...
anyways i can't tell the difference ... lol

 

[aquariuscsm]

As to her mentioning it running quiet,Pennzoil is legendary for making engines run smooth and quiet. Although I'm using QSUD right now,I normally use PP and will be going back to it next oil change.

 

[RooflessVW]

Didn't wipe up all the oil after filling and vibration is helping it migrate across the valve cover.

 

[JohnnyJohnson]

Had a problem like that on my 2004 Toyota. Cleaned it off and replaced the old fill cap it has not come back.

 

[Astro14]

It IS a coincidence.

Correlation (things happening at the same time) is not causality (one made the other happen). Clean it up. Put a new gasket on the fill cap.

 

[oil_film_movies]

You have been changing the oil way too often with a quality conventional Chevron oil in the past.
I think you're just seeing normal build-up on an older engine. Age of the engine can also explain more consumption.
Operating in cold weather is probably what caused the film you saw since it takes a little longer to warm up and might not get all the water condensate burned off.

 

[CT8]

The crankcase is full of oil mist, droplets and blow by gasses when the engine is running no matter what the base oil is.

 

[MolaKule]

Originally Posted By: OilUzer
...Can Synthetic oil evaporate and cause oil film?

...I am seeing this oil film near the engine oil filler cap, PCV valve (which is right under the cap) and surrounding area after changing the oil from dino to synthetic.



If the oil is brought to a very high temperature it can but I doubt this is the situation here.

As CT8 stated, "The crankcase is full of oil mist, droplets and blow by gasses when the engine is running no matter what the base oil is."

I think what you are seeing is a condensation situation where vapors and the hot oil mist is condensing onto the cooler surfaces, i.e., phase changes.

Phase Change

If the crankcase does not have sufficient vacuum to suck the vapor(s) into the combustion chamber, then this could be one cause.

Also, even after the engine is shut down, there is a brief period until full cool-down in which there are vapors in the engine that have the potential to leak out and condense onto "unsealed" areas as Astro referenced.

 

[OilUzer]

Thanks for your responses!

as I mentioned before in almost 4 years with this car, this is the first time ever that I have seen the oil film and I thought maybe there are some additives in the synthetic oil (vs. dino) that maybe more susceptible to evaporation ... the engine coolant temp is typically in 183-186F range and does not go above 188F.

anyways, will try to clean the area and change the gasket or the cap and see what happens.
may check the pcv valve if the film comes back.