3.0 Ford Oil Pan Gasket - Mobil 1

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Jan 16, 2004
Albany NY
Hello Everyone. I am new to this board and I must say I can't stay away. I keep logging on at work and may soon be fired . I have a 2003 Mercury Sable with the Vulcan 3.0 V6 engone. I bought the car used with 9000 miles on it. I couldn't sleep thinking about using 5w20 oil, so I went ahead and did my first oil change with Mobil1 5w30. (I drive about 600 miles per week, so I need the engine to last.) Soon after the first Mobil 1 oil change, I began seeing about a tablespoon of oil on my garage floor each morning. I would wipe it up, and it would reappear the next day. I made sure everything was tight. (plug, filter etc..) The leak persisted. This went on for a couple of months and I finally decided to take it to the dealer. I did a quick oil change with Motorcraft 5w20 first just to be sure that if I blew out a seal, that they would not figure out that I had not followed the 5w20 oil reccommendation. Anyhow, first they put a new filter on it and told me that a service bulletin stated that I needed to tighten the filter an extra 1.5 turns. I told them that the leak was not from the filter, but I think it was oily in that area because of the recent oil change. Of course, it still leaked and I brought it back again and they discovered that the oil pan gasket was leaking. They replaced it under warranty and it now does not leak. OK..... Sorry about all the reading, the question is.. Could the use of the Mobil 1 5w30 have had anything to do with the leak? It did not appear until I changed the oil that first time. I would like to go back to using it. (5w20 still gives me the sweats.. it took me years to try 5w30). I know that it does not seem likely, but it seems like a weird coincidence that the gasket failed at the same exact time as I switched to the synthetic.

Any advice would be welcome.


I keep logging on at work and may soon be fired .

I've been saying the same thing. We have an no internet policy other then for business use. As long as you do your work, I don't think they will care.

On to the subject, no. I don't think Mobil 1 had anything to do with this. Any good synthetic will contain esters and sometimes in older engines, they can clean off oil dino oil previously used and this will cause oil seapage. Synthetics don't cause leaks, but find them if they exist. You should be good to go. BTW, Motorcraft 5w-20 is an excellent oil and unless your going to extend drains, your fine with that oil. It's very good IMO.
I doubt the Mobil 1 caused the leak. When I bought my '99 Taurus 24 valve (used) in 2002 it only had 21,000 miles on it. I immediately put Mobil 1 5w/30 in and it's on it's 3rd rotation now and I haven't had any leaks. Probably just a coincidence.
When I used Mobil 1 5w-30 in my Ford 3.0 Vulcan, it burned a quart about every 1500 miles. I switched to GC 0W-30 and the oil consumption at 1200 mile to date is ZERO.

BTW, I'd never use 5W-20 oil in this engine. I'm happy with the GC and my mileage remains at about 25 mpg 50/50 city/highway driving.
The Motorcraft 5W20 seems to be an excellent oil at a bargain price.Stable stuff.
A lot of 5W30's shear down to a 5W20 anyways so might as well go to the 5W20 to began with.
I would not blame M1 for the pan gasket leak. Ford's 3.0L have a history of leaking pan gaskets. I had a 97 Taurus and currently own a 99 Taurus, both with Vulcan engines. Both have had to have the pan gasket replaced. The 99 just let go all at once. Thought I had the Exxon Valdiz parked in the driveway!

As a side note, posters on another forum report improved engine performance after replacing a leaking pan gasket. Theory is that it corrects a vacuum leak, but not proven.

My Ranger with the 3.0 motor leaked like a "stuck pig" on Mobil 1 (rear seal, valve cover gaskets and oil pan). I know it's not possible that it was the oil, but I switched to Amsoil on my subsequant vehicles and had no leaks. Remember, you need to do what works for you, and that's not necessarily what works for others!
At 600 miles per week I would stick a good ACEA A3 30wt synlube in that thing . This an application where a guy could get the full benefits from a synthetic ...... no doubt

Castrol 0w-30 comes to immediate mind here

Q-State and Amsoil have nice A3 5 & 10w-30 wts as well .
Of all the synth's I've tried, M-1 had the LEAST problems with leaks...actually non-existant. So while you may have exacerbated the pre-existing poor seal with a better flowing oil, the leak was inevitable and now that it's fixed you can safely use any oil you like. ie. it didn't cause the leak directly.
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