Gotta be leaking if you can smell it under the hood. There's two ways to find an elusive leak. One is by adding a small bottle of dark purple dye, driving a little, then searching with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. That is usually used when there's an obvious leak but you can't find from where.
When there's little pooled oil or drips, you can use a smoke machine to inject a white, non-toxic smoke into the dipstick tube, then you look for where that smoke sneaks out. That will work when the leak is in a non-pressurized part of the engine such as the oil pan, cylinder head cover, and the return passages. It might not work if the leak is in a pressurized passage.
Sunday, October 14th, 2012 AT 4:07 AM