Minor Leak: A small leak might just result in some oil splattering on the engine and eventually a slightly lower oil level. You'll likely see some oil stains in your engine bay. While annoying and needing repair, it's not immediately catastrophic. Keep a close eye on your oil level and top it off as needed.
Significant Leak: A larger leak can lead to:
* Low oil pressure: This is serious and can cause engine damage very quickly. Low oil pressure means your engine isn't getting sufficient lubrication, leading to overheating and potential seizure.
* Oil fires: Oil leaking onto hot engine components can ignite.
* Oil fouling other engine parts: Oil can get on spark plugs, ignition wires, and other sensitive components, leading to misfires, poor performance, and more costly repairs.
In short: Driving with a leaking valve cover gasket is not recommended. The longer you wait, the greater the risk of more serious problems and higher repair costs. It's best to get it repaired as soon as reasonably possible. A regular oil change is also recommended to prevent additional contamination.
