Synthetic motor oil
About 10 months ago I put Mobil 1 into my 64 327. About a month ago someone mentioned having read that synthetic oil in older vehicles results in leaks. So, put my front end up and yes, a leak has developed around the timing chain gasket. Not much, just a drop at the lowest part of the flange and moist around the gasket from the oil pan down. Since its oil change time anyway (calendar not mileage) I switched back to petroleum based oil hoping my leak will stop but 35 miles later still leaking slightly (streak on finger lip after driving 10 miles). Anyone have leak issues with synthetic oil? Might switching back to petroleum resolve this?
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Re: Synthetic motor oil
I use multi grade 10 W 40 Valvoline motor oil in my 327 and 350 engines. Add one 4 ounce of ZDDP if using SM rated motor oil. The leak you have may not go away even if you switch back to petrol based motor oil because of the the very rapid flowing Mobil 1 oil. Mobil one is an oil for motors that run at high speeds and high heat conditions; aircraft engines or very high performance engines. The Mobil 1 oil will last longer than petrol based oils but for older engines with cork and rubber gaskets the oil seams to find a way through the gaskets via a minor metal surface seam not seen with the eye. Some engine builders use various gasket sealers on the surface of the gasket in an effort to seal the surface. Modern engines are sealed with RTV not gaskets and the use of synthetic oil is common for high performance applications including power trains, grease, etc. I would change the oil and filter, add the ZDDP. If the leak does not stop try an engine sealer to expand the gasket and hopefully stop the leak or make it a minor thing you can live with. Research motor oils and there applications via the web. The recent changes on all oils to meet the EPA rules have impacted the old car hobby along with the blended gasoline. You could use Diesel Oil to meet your spark fired engine application but these oils are also being impacted by EPA rules. Be aware that Diesel Oil like spark rated Castrol contain more detergents to combat soot. -
Re: Synthetic motor oil
Thanks Richard, I'll give ZDDP a shot. As for engine sealer, any concern with it clogging some of the tiny oil passage holes?Comment
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Re: Synthetic motor oil
Simpler solution that adding ZDDP. Buy Shell Rotella or the oil of you choice that meets at least CH-4 specs. Cheaper that buying the oil and additive.
There are many, many threads here on motor oilDick WhittingtonComment
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Re: Synthetic motor oil
Search on this site for numerous postings by Duke Williams to find info about motor oils. Use the oil grades suggested and you will not need to use supplements or additives.
Best regards,Comment
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Re: Synthetic motor oil
Ed------
Are you sure this leak was not present BEFORE you switched to synthetic oil? Due to the "myths" surrounding the use of synthetic oil you may have become much more "sensitized" to leak detection after you switched to Mobil 1 than you were prior to that time.In Appreciation of John HinckleyComment
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Re: Synthetic motor oil
Ed: The engine sealer should not cause a flow problem it will swell the cork and rubber and hopefully stop the leak. Next season when you change the oil do not use the sealer again as the gaskets should hold. The sealer is solvent based but not enough to cause a plugged oil hole on say a hyd. lifter.Comment
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Re: Synthetic motor oil
Richard - will try the sealer.
Joe - Excellent point. But the first thing I noticed after driving the car up onto the ramps, and letting it sit thru my dinner before getting under, was a drip on the floor. And, the floor is not stained where I usually park. But again, good point. Not sure where to go with it since I've never had leak trouble following gasket replacement.
To all - thank youComment
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Re: Synthetic motor oil
Synthetic oils don't create leaks, they just find existing leak points alot easier than petroleum based oils. Repair the leak and then run Rotella 15W 40 and you wont need any additives.Comment
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Re: Synthetic motor oil
my 22 year old silverado started to leak oil after using mobil 1 for all these years so i switched to "HIGH MILEAGE" motor oil and all the leaks have stopped and the engine runs fineComment
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Re: Synthetic motor oil
Thanks. Sounds like a great way to go. What is "High Mileage Motor Oil"? I have 83,000 miles but I doubt that mileage matters in this case.Comment
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Re: Synthetic motor oil
Ed------
Just about all the major brands have a "High Mileage" oil available now. It's supposed to be for engines with over 75,000 miles on them. How it differs from the regular stuff I do not know. However, I use it in the old Cadillac. It does cost a little more than the regular stuff but not enough more to be of much consequence.In Appreciation of John HinckleyComment
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