I have a 1995 ex odyssey van my question is what is the best rear main seal solution on the market that will stop the leak while driving especially over 45mph.I have tried 3 different types of liquid solutions. I may loose a half quart of oil per week.
The liquid solutions don't work.
If you are using regular oil then switched to synthetic oil and the engine has high mileage on it then the oil could get past a seal that is worn.
If this is the case switch back to the regular oil and see if the leak slows down.
If it doesn't slow down then the only way to stop the leak is to replace the rear main seal.