Oil stop leak formulas are designed to soften rubber seals and make them expand (therefore seal better) but should not harm anything if you use add directed.
Is Lucas good for your engine?
A: Yes, In addition to being great for your engine, you can also mix it 25% / 75% a manual transmission and 50% / 50% in the differential. Lucas Oil Stabilizer blends with any petroleum-based or synthetic oil, and is formulated for gasoline or diesel engines.
How do you use Lucas Engine Oil Stop Leak?
https://www.youtube.com/watch?v=AHGwRuPDV3Y
How much stop leak should I use?
Use 1/2 bottle for four cylinder engines. One bottle treats up to 4 gallons. For larger systems use one bottle for every 3 gallons of coolant capacity. Small engines or other small systems use 3 to 4 fluid ounces per gallon of fluid capacity.
How long does it take for Lucas Engine Oil Stop Leak to work?
It may take 400 miles or more (mine took this long) for it to work itself into the seals and affected area's. Don't expect magic to happen after a few days. Continue to monitor and check your engine oil levels and top up when needed. Remember, as it takes time to work your engine may still leak hence check and top up.