I just bought my Bronco and it has a small oil leak. Two small quarter size drips in my garage after two weeks. The seller is running synthetic oil. I have heard that synthetic oil can cause leaks in an older engine because it seaps through where regular oil won't. Is this true? Is it OK to switch back to regular oil after running synthetic? I have heard that synthetic breaks regular oil down if it is mixed.

 

Does anyone have a particular brand of oil that they favor or stay away from?

 

I have heard the same thing about the synthetic oils. I like Pennzoil. I can't explain the tech reasons but it was explained to me plus I have worked on and rebuilt my fathers engines and he as well uses pennzoil.

 

Castrol GTX in my gasoline vehicles......

 

Some have recommended AutoRx for various problems. Some users have claimed relief from leaks, etc. after using it. My truck is not leaking from using syn oil.

 

In Bronco terms, that is hardly a leak! Surely nothing to be concerned about from an engine longevity standpoint. If it leaks oil, it leaks oil. If you switch to non-synth it may slow down, but I doubt it would stop. The ideal solution would be to find out where the leak is coming from and repair the gasket/seal responsible. Or if the main concern is about the garage, put down a piece of cardboard or oil absorbent mat.

 

Dino oils like Valvoline, Mobil, Exxon Uniflo will do just fine as long as service intervals are followed. There is a lot of threads about this sort of thing in the Oil & Lubrication Forum. https://www.ford-trucks.com/forums/f...?s=&forumid=70

 

I have always had good luck with Vavoline high millage. Pennzoil has parrafene in it and if you ever dig into an engine that used pennzoil it is nothing but gum and gook. That just my opinion.

 

My fathers engine had over 250K on it and not a bit of gum. His current engine that I rebuilt has over 300K on it and he hauls with it just about every day so it's not just driven as a daily driver it's used as a work truck.

 

The general consensus is that if it leaks at all, synthetic will leak worse, but modern synthetics wont "cause" leaks. The original Mobil One did cause leaks because the Poly Alpha Olefin base oil shrinks seals. Modern synthetics are either non-PAO or have seal conditioners.

Bottom line, you can switch back to conventional and it may solve your problem. Chevron/Havoline are my current favorites. Pennzoil is now owned by Shell and today is excellent, not the same as years ago.

Jim

 

This might help some of us?

http://www.corvair.org/chapters/chap...about_oil.html