Mobil One Deposits

Hey All.

I have used Mobil One in my engines for the past 10 years or so. Recently after Mobil One's recent reformulation (Tri-Synthetic) I began to notice carbon deposits on the underside of the rocker cover in my 300E. It has 10k Miles on it since a dealer rebuild and I change my oil every 3000 miles (Yes, I change Mobil One at 3k too) I would attribute this to the car, but my 1999 4 door Chevy Dualie with a 454 is having the same thing occur to it and I have used Mobile One in it since the very first Oil Change. I use brand name filters and don't drive too radically... Has anyone else had these problems? They have only started within the past year for me after using Mobil for almost 10 years. Please post any replies you might find


Jason
1986 300E
1999 Chevy Crew Cab Dualie 454

This one will be flaming soon!

Have a great day,

[johngray]

Larry, these oil discussions are like the Terminator, they just won't die.

I have used Mobil 1 Tri synthetic as well, but its in a MB 92 300D 2.5, 84 300D turbo, and 86 190D 2.5. I didnt take apart the engines in all of them, but from a breif look in the past, I didnt notice any deposits. They claim it doesnt cause engine deposits, but it probably does cause some, but much less than with conventional oils. If you use some engine cleaner every 50,000 miles, it should remove all of it.

I believe that deposits on the valve covers and such places are something to watch for, but not the important indicator. I would be much more interested in areas like piston rings and ring grooves. You will not have the chance to see these areas until overhaul time, of course.

Good luck,

[longston]

Jason,

I was curious about what you were saying regarding carbon deposits inside your valve covers. So I called the Mobil tech line, 1-800-662-4525, to ask them what they thought. You might want to call them yourself, but I was told that they have never had a question, comment, or complaint similar to yours. And as far as deposits are concerned, their rep stated that the use of their oil decreases the formation of them, and cleans them out of your engine. You can also get more info by going to their website, http://www.mobil.com.

Hey, Larry, they also manufacture a synthetic DELO called DelVac 1... Use that in your lawn mower

[Edited by longston on 02-01-2001 at 03:24 PM]

longston,

Yes, Delvac One has been out awhile. Mobil Delvac has been around for a long, long time and is another good universal grade oil, now they took it synthetic. But, it is a Mobil product, Delo is a Chevron product. If you can afford it, it would probably be as close as you could come to the perfect diesel engine oil.

Have a great day,

[Michael]

I have had great success with these products in both Honda and Mercedes cars; even using the new stuff (I use exclusively 15W-50 year-round in my gas cars)I've noticed no deposit accumulation. Zero.

I have such confidence in Mobil synthetics that I just bought 2 cases of Delvac 1 (it was a B$%#h to track down) for my soon-to-be-delivered '92 300D.

Stay on Mobil-I've got to figure they'd be interested in your unique-seeming situation. Good luck!

[Edited by Michael on 01-31-2001 at 09:55 PM]

Don't scare me. I just changed over to Mobil 1 15w-50from Chevron Delo 15w/40. I have used Mobil 1 and Redline synthetic oils on different cars. Now, I am wondering if I did the right thing. Hope you find the answer and tell us about it.

s60,

Do you have a gas car? Either one of these oils is excellent. If you have a diesel, the Mobile DELVAC One would be a better choice, but I wouldn't run out and drain it unless it's due draining, to change to DELVAC One.

Good luck,

[Kebowers]

If you are experiencing valve cover deposits with your frequent changes of Mobil1, I urge you to get in contact with Mobil's customer service folks. This is NOT a usual condition. DO NOT throw away the used oil. Make careful observation and record the engine operating paramaters--temp, fuel economy, driving syste, etc. The lube tech folks at Mobil will be very interested.

Is the engine reaching full operating temperature? This would be about 85 degrees C, or better? If not, I would expect that you would have deposits from any oil.

Have a great day,

Larry,

It is a gas engine, and it does reach 85-90 degrees Celcius. Besides, inadequate operating temperature would cause sludge, I have NO sludge and the oil looks crystal (amber) clear at 3k but smells alittle funny. Just carbon deposits on the inside of the rocker cover.

[longston]

Jason,

All I can tell you is, after yet another conversation with Mobil Oil on your behalf, YOU should follow Kebowers advice to the letter!
There is no reason that Mobil 1 should account for ANY deposits in your engine at all! Call them, they are best positioned to resolve this, not us!

But! Let us know the result! PLEASE!

Hey all,


More news in the endless saga. Spoke to Mobil and they acted shocked. The only thing that I can figure is that it was alittle bit of trash left in the valve cover at the dealership during its rebuild ( I let my teenage sister borrow my second car (merc) when her integra was in the shop and she ran over a leaf spring at 2 oclock in the morning.... windowing my beautiful oil pan. Luckily I got my insurance to pay for the rebuild(roadhazard) Afterwards, they were sorry and so was I) Anyways, the cylinder heads (pulled them) and the top of the piston surfaces looked incredibly clean, and it is the tightest engine I've ever seen ( I normally work on small block chevys.... I can hear the groans now). It restored my faith in Mobil, but I'm still alittle leary. Well, I hope that this eases some of your minds. Thanks for all your help,

Jason McNeese
86 300E 88k miles
99 Crew Cab Chevy Dualie
ASE Parts Specialist