I have done it on a 20 year engine with 200k miles that has never been opened, rebuilt or resealed in any way. Never caused a problem. I also started using it in my C280 at 60k miles. Now has 145k miles and still doesn't leak a drop.

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Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record