Yup, I must of left off the oil cap the last time I added a little oil, or there is a slim chance it somehow worked its way off by itself. I'm guessing its been like this for the last 800 miles or so.

There hasn't been any change in performance, no check engine lights came on, the oil level and color is unchanged, and a single rag cleaned up the small amount of oil that splatted out.

The question is, would this cause any permanent damage?

 

Unless you lost enough oil to cause a low pressure situation (which it sounds like you didn't), it is unlikely that you caused any permanent damage. You may however want to change your oil again as soon as possible. If you drove in any wet or dusty conditions, there is a reasonable chance that your oil is contaminated with things you'd rather not have in your engine.

 

i said something stupid....

EDIT - im thinking of when you pull the dipstick out while the engine is running. my bad

 

No big deal. I worked at many quick oil changes in my late teens/early 2os. When u change oil in 80 to 100 cars a day. You might leave a oil cap off every now and then. Just a small mess is all it leaves.

 

The 4Runner doesn't seem to be affected vacuum wise with leaving the cap off.

 

No biggie I drove an est. 300 miles with mine off. After I freaked out a bit the level was ok I sprayed some simple green and it was all good had to get another cap though.

Aaron

 

Thanks for all the replies, it looks like I may have dodged the bullet on this one. I'll make sure I pay more attention next time.

 

Because there is no vacuum in the crank case, just the intake manifold.