I accidentally added steering fluid
(about 1/2 pint) instead of oil. What will this do to my car ('99 Audi A4)?
I advise having the oil and filter changed ASAP. I think you can safely drive the car a short distance, but I would have the oil and filter changed TODAY if possible. Since it’s such a small amount of PS fluid, this will probably NOT cause any damage, but don’t push your luck.
how much did you drive it since you added the power steering fluid?
if you haven’t driven it, i would change it right where it is.
The good news is that power steering fluid is oil, a low viscosity hydraulic oil. I don’t think the sky will fall because the 5 quarts of engine oil was diluted with one cup of oil that has a lower viscosity.
Listen to BLE. So you have 1/4 quart hydraulic oil added to 4-5 quarts of engine oil? No big deal. Get an oil change when convenient, more for peace of mind than out of necessity.
Steve and BLE are correct. In fact, back in the '50s, some people used to add a qt. of transmission fluid (which is very similar to PS fluid) to their motor oil a few days prior to an oil change in order to help clean accumulated sludge from the engine.
I would not recommend keeping the PS fluid in the crankcase for an extended period of time, but doing an oil change within a few days should be soon enough to prevent damage. Be sure to change the oil filter also, and be sure to be more cautious about adding fluids the next time that you check under the hood!