I'm worried about switching over to synthetic oil. When I change my oil, I get a couple of knocks after start up, when the pressure starts to go up the knock stops and Inever hear it again, until the next time I change my oil, that is. Anyway, I was thinking about changing over to synthetic in hopes of prolonging the enivitable, but I don't want my 190,000mi engine to spring leaks. It doesn't leak a drop now, not one drop! Any opinions?

 

Synthetic won't create leaks, but it might worsen ones that are there.

 

Why switch now, if your current oil is working for ya. A knock after the oil change isn't anything to worry about.

 

I'm hoping that the switch will help the engine last longer and perform better. I heard that an engine can have a leak that was plugged by conventional oil, and that the synthetic will re-open the leak. Is this true?

 

It happened on my 91 Jimmy with 150000 miles on it. I switched to synthetic and after 2 oil changes it began leaking from the rear main seal pretty bad, leaving puddles. I switched back probably 3 oil changes ago. It has since stopped leaving any drips, but the pan remains wet. I need to clean it up and see if it is still leaking. Just my experience.

 

true dat, it is probably just your car warming up. Mine does the exact same thing too.