The first thing I did when I bought my '82 back in April '03 was to replace the current oil with Mobil 1. I thought it was the best thing for the engine. I've replaced it every three months since. It started to drip some from just under the oil pan and has gotten worse lately. I believe the reason is due to switching to Mobil 1.

So what should I do? Any suggestions would be helpful.

At this point all you can do is repair the leaks. Once the gaskets and seals are replaced, the Mobile 1 won't be any further problem, and will be a very good oil to use. Putting it in an engine with some miles on it usually has the same effect as you have now. Going back to the old oil won't stop the leaks.

Ken Styer

Try replacing the oil pan gasket with a 1 piece silicone gasket. Might as well replace the rear main seal while you are there.

What I've discovered is that cork gaskets, and synthetic oil don't mix. try a 1-piece silicone or rubber based gasket, and yes, while you're there, might as well hit the rear main seal. You should be golden after that.
Good luck.

You are correct that your leakage is from swithcing to Mobil 1 as it does leak more than convention oils

It's not that Mobil 1 or any other synthetic oil is more prone to leaking in and of themselves, it's the fact that their superior qualities in lubricating and cleansing tends to clear out crud residing in gaps in shrunken seals and gaskets. When the crud gets cleaned out, the gaps open and the oil begins to leak. Once the seals and gaskets are replaced, the oil won't leak.

I don't have Mobil 1 in my engine. But after breaking in the new engine on conventional oil, I have switched over to a full synthetic (Amsoil) with no sudden leakage problems. I even ran the engine flush that Amsoil has to remove any debris or contamination left by the old oil with no ill effects. That's my .02 cents.
Sarge

Why every 3 months? You want to make them richer !!!!! syn. oil lasts longer!Try it for at 5000 miles.

If there is no crud to clean out, and the gaskets haven't been worn or altered, it won't change anything. Any engine under 20 or 30 thousand probably won't leak when switched, unless those miles include many years. Cork will hold syn oil if it was installed and syn oil was used after some break in miles or even after several oil changes with standard oil.
Syn oil is better, and changing the gaskets and seals can be worth it. If you drive very little or a lot syn is a good choice. With my other two cars, I'm in between. So my oil changes are necessary due to contamination. No matter what oil, I need to change it to get rid of the contamination. The extra cost of syn is not worth it in this case. Longer driving will allow the engine to clear some of this through the pcv system. Only starting once in a while, the syn will hang on to engine parts longer so there is less of a dry start. Right now my C3 sits a lot so the syn would be better, but I just got it after sitting 5 years, and if I change to syn it will likely leak. I have other things to fix before I start on oil leaks so I am keeping standard oil in the car at this time.

Ken Styer