Adverse effects of driving with oil cap off?

[havic]

My friend was adding oil to the engine and forgot to put oil cap back on to the engine. She drove the car like this for 60 miles before she put it back on. She felt the engine riding a litte rough when she realized this. What are the affects of driving the car like this? Can any serious damage occur? Thanks.

[Brian R.]

My hunch is that it would have no effect during such a short period.

[VTISC007]

Check the dipstick. See how much oil it lost. Probably not much.

[Tufftommy]

My girlfriend did the same thing on her '88 witht 3.0 V6. She drove errands around town and complained that the idle was surging. I popped the hood and the cap was still sitting on the intake. This was 2 years ago and nothing ever came of it...

[sha_zapple]

Well, with the cap off there would be no oil pressure, and the roughness would be from the lack of oil in the system. Probably no ill effects from such a short distance, but it still isnt very good for the engine

[Brian R.]

Originally Posted by sha_zapple

Well, with the cap off there would be no oil pressure, and the roughness would be from the lack of oil in the system. Probably no ill effects from such a short distance, but it still isnt very good for the engine

I hope you rethink this comment.

[sha_zapple]

whys that? If Ive gotten something wrong please tell me.

[Brian R.]

Originally Posted by sha_zapple

Well, with the cap off there would be no oil pressure

The oil pump supplies the oil pressure to the engine and removing the filler cap has no effect on the pressure supplied by the oil pump. Removing the filler cap only allows some air to enter the engine, and perhaps some blowby gases to escape, depending on the condition of the rings.

[sha_zapple]

Makes sense, but with no cap, would it not be an 'open system' and therefor no different pressure than normal?

[Brian R.]

The pressure inside an engine has nothing to do with oil pressure.

Read this:
http://auto.howstuffworks.com/engine1.htm

Particularly the part about lubrication.

[sha_zapple]

ahhh, thanks dude

[Brian R.]

You're welcome. Nice site for alot of things.

[Doug Rodrigues]