letsgoagain

Added a little oil recently and left the oil fill cap off. Drove it about 300 miles before I discovered the cap sitting right on top the air filter housing exactly where I left it. Wondering what if any harm was done and if I should change the oil and filter again. Just changed the oil a week or so before I forgot to put the cap on.
Any ideas?
Thanks

Jeek.OlllllllO

Not sure but I would change it and change the filter just to play it safe

Jeepin on a budget
-Jeek

catahoula

My very first oil change at the stealership. Had 3000 miles on it. They forget to put it back on and found out myself when filling up I usually check my oil. Got a new oil cap from them and asked if there would be a problem. They told me no and 40,000 miles later I have not had a problem and have not been back to them either for any type of maintenance as well due to lack of trust. They did change it again. and does not hurt to play it safe.

meep97

I would just change the oil again to make sure there's no particles in it. An oil change is cheap when you compare it to a new engine.

shabbernigdo

i highly doubt that there would be any harm from leaving the cap off and if any dirt / dust did happen to make its way in thats what the oil filter is there for.

Mike Davis

The most harm would be IF oil was thrown out of the cap hole. Look for evidence of oil sprayed about. If no oil evidence and oil level ok, just drive it. If it sprayed oil, add up to the correct level and drive. The chance of anything getting into the oil system is small.

yo_marc

You're probably a-ok.

I've left my oil cap off for a day or so -- and left the valve-cover breather line off for ~500 miles. Motor now has 140K miles on it, and is still running great.

Jersey_Devil

Ur fine. Don't worry about it..... Been there, done that.

Sent from my obama monitoring device

JKlad

The valve-covers on the JKs are baffled, so there's not the issue of the valves throwing oil out the filler hole at higher RPMs like in the "old days". If you were driving along very dusty roads/trails for some time then it is possible that the oil may have become sliightly contaminated however I wouldn't worry too much about it (that's why oil filters were invented in the first place after all).

ronjenx

There wasn't a single oil filter among my first 7 vehicles.