Normal oil fill cap condensation?

I have it but it's a darker rust color.

160k mile Socal truck. 90 miles a day daily driver. 10k oci and parked outside. I didn't even know i had it until I saw another thread about it. My guess is it's due to the long oil fill neck. Never had a car with one like that. What ever condensation or oil burn off collects in there.

I'm not worried at all about.

 

It is not related to the oil change interval. It is moisture content in the air of the crank case.

Seriously, don’t worry about it.
Just keep doing what you’re doing.
Monitoring and maintaining your truck.

 

Completely normal! These threads pop up every winter!

 

I do mine every 2500 -3k.

 

Concensus seems to be that it's normal. I take it yall who experience this do a lot of short trips?
I don't live in the cold but rather down south near the humid coast and have yet to see this. My old job had me doing 30 miles to and from work. Current jib has me just 7 miles each way. I reckon I'll have to keep an eye on it.

On a similar note, where is the oil temp gauge probe located on 3rd gens?

I have a scan gauge that now a permanent resident on my dash and while the water temp will hit 180-200 in half the drive, with these recent weeks colder Temps the engine oil temp will maybe hit 140 before i reach destination.

I wonder if I'll start to see it.

Those worried about a little condensate ever get paranoid about fuel dilution? Especially those who do 10k OCI?

 

Condensation is completely normal in an internal combustion engine. As the engine heat cycles it will draw in cool moist air and water is a by-product of combustion. Both contribute to condensation in the oil.

Also, to add, an engine will heat cycle naturally even without running. As temperatures rise in the day and cool in the night, so does the engine and air in it. This heat cycling is sort of like breathing, hot air expands and pushes out, cool air contracts and breathes in drawing in moisture with it. This is way engines that sit need oil changes as much as engines that are driven.

Also, a part of coolant is water, this will evaporate over time, especially when hot, reducing the level in the reservoir. ( the glycol evaporates too ). This is also completely normal.

I would suggest base lining your coolant level and your oil level under the same conditions with over a couple weeks. So temperature and time since last run. If you notice a loss in coolant and gain in oil level then maybe you have an issue. Although you day your oil looks fine... and coolant and oil mixed in an engine is milky so I think you should be fine.

 

Well, monitored all week long under same conditions after driving it. Coolant and oil level stayed the same, no rusty/contaminated oil in the cap or tube. Conclusion; Since I changed oil back in July and it is now January, had to of been condensation build up within that time frame. Going to keep on, keeping on. Thanks for the input guys.

 

Lots of short trips? Change the oil every 6 months regardless of mileage. Short trips are the worst as it allows the oil to breakdown prematurely and become acidic. Water and fuel in your oil breakdown additives quickly. Oil is cheap, your engine is not.

 

That ain't normal. Heck, my '97 Civic daily driver has never shown a spec of moisture under the oil filler cap, and it does mostly short trips.