I recently changed my oil with 5w-20 Mobil 1 oil and filter and was wondering if it will cause any issues? I have 126,000 miles on the motor and had been using Motorcraft oil.

 

Just don't use the high detergent formulas. They can wash away the gunk that is keeping the seals leak free. If you do get a little leak, try adding a qt of Lucal oil stabilizer. For lubrication perposes, it will do fine.

 

Thanks! I did not use the high detergent oil but I will keep an eye out for leaks.

 

With your kind of mileage, you might see front or rear main seals dribble a bit. I wouldn't expect anything major though.

 

<TABLE border=0><TBODY><TR><TD class=bodyText xmlns="">Myth: </TD><TD class=bodyText xmlns="">Mobil 1 will leak out of the seals of older cars. </TD></TR><TR><TD class=bodyText xmlns="">Reality:






</TD><TD class=bodyText xmlns="">Mobil 1 does not cause leaks. In fact, new Mobil 1 was tested in dozens of industry standard and original equipment manufacturers (OEMs) tests to prove its seal performance. It is fully compatible with the elastomeric materials from which all automotive seals and gaskets are made. If an older engine is in good condition and does not have oil leaks, Mobil 1 provides the same advantages as when used in a new engine. ExxonMobil recommends taking measures to repair the leaks, then using Mobil 1. ExxonMobil also recommends following the automobile manufacturer's manual for the proper oil to use.

That's what Mobil's web site say's

</TD></TR></TBODY></TABLE>

 

Well it works like that as long as the seals are in perfect shape and no gunk has built up around them. Synth is slicker than dino and can get into smaller places, like the little holes in the crud built up near the seals.

 

plumbergeek: way off topic, but how do you like the 305s with your 3.73 gears? Any rubbing with just a leveling kit? Love your truck BTW!

 

No rubbing except @ full lock the tire's rubs on the spring's a little, & thanks! I have the BSEG like yall!

 

All I use is Full Synthetic since the first oil change at 500miles. Mobil 1 is what I use most of the time.

 

I've been a long time user of Mobil1 full syth oil in all of my vehicles. Tried Mobil1 full synth 5W-20 in the V10, and noticed way too much oil consumption when towing, hauling a load and just general use. My last oil change I added 2qts of oil over the life of the 5000 mile oil change interval. I know this is "normal" but I had to switch back to Motorcraft semi syn 5W-20. They don't give Mobil1 away to be adding so much of it over the life of an oil change interval.

My 2 cents, others have had different experiences with Mobil1 in their crankcase. Just keep an eye on the oil level.

Enjoy,
RustyFuryIII

 

I've used both Amsoil and Mobile1 in all of my vehilces and never had a single problem from any of them. My old F150 (5.4) had 132k on it when I traded - no leaks. I got my V10 Excusrion with 114k on it and the first oil change I used Amsoil - no leaks and I'm up to 130k now. I'm getting ready to change the filter and top it off. So far, the dipstick hasn;t dropped a bit.

My wife's 01 Accord v6, with 99k. Benn running syn since 40k. No leaks!

I think it's a common "urban legend" that syn will make the seals leak. This may have been the case years ago, but today, synthetics contain "seal swellers" (mineral oil) that the seals absorb... fat seals = a tight seal.
I found this Popular Mechanics article that provides a breif explanation.

 

There are a few of us here that have tried the full-syn oil and has had problems with it evaporating. For instance, when I first tried it, I used a quart every 2000 miles. Went back to dino and never used another drop. Don't be suprised if your engine loses a little oil with that many miles going to full-syn.

 

Thanks guys for your input! I will keep an eye on my oil level and if I find unusual oil consumption I'll go back to Motorcraft's semi with no reservations

 

After 126,000 sucessful miles with MC, why did you feel the need to switch?

 

I bought it w/ 100,000 miles on it last May so they are not all mine. I have used Mobil 1 in my Jeep Wrangler though and was pleased with it.