I recently (within 7-8 months) have swithced to using Mobil1 Synthetic Oil. Ever since then - and this may be a big coincidence - I have had a small oil leak coming from either the drain plug or the oil pan itself. By small I mean maybe 1 drop of oil every 3-4 days. Just enough to be a PITA. I may have a gasket leak somewhere or the drain plug is messed up or crossthreaded.

Could me starting to use a synthetic oil SUDDENLY cause an oil leak to begin? Normally I would not care about a little oil - but it's leaking on the floor of my new garage

I'm getting jackstands in a few days so I can crawl under there with a good light an pinpoint the problem area. (I'll be careful - I'm buying 6 ton stands x4)

Thanks for any ideas.

 

I was told switching to synthetic on a higher mileage car can cause leaks. I dont know why, that was just what I was told. Im sure someone on here could tell you why.

Bo

 

Here is what I heard years ago from a technician, I dont know if it is true or not. He said synthetic oil is actually more slick than regular oil and can make its way past older seals easier. Just wanted to say that. As far as oil leaks go, my car has 127,000 on it, I have sealed the intake, replaced all 3 seals in the timing cover, now my oil pan gasket is leaking, I plan on doing the oil pan sometime this week, then hopefully leak free car again.

 

Synthetic oil does leak by easier. It is designed to give better luberaction and penatration to parts. You are seeing the down side to swapping on an older engine. The good news is if you ever do a rebuild, you will a get better lifespan out of it.

 

Probably the good old intake manifold leak. Thats what I have to get fixed first thing this spring. Heres a link: http://www.projecttransam.com/projects2.asp