Mobil One oil woes!!!

[Bob G ✝︎]

I was warned, told my engine would leak like the red sea. Last week I noticed an incidental puddle of fresh oil at my right front tire. When I pulled the car out, there was a mix of transmission fluid and Mobil One.
 
Well I had not driven the car more that 40 miles to and from my mechanic so I suspected something slimy cooking. I purchased a new transmission filter kit and an oil filter kit. My mechanic who does alot of new Mercedes-Benz automobiles gave me a credit.

We also found a modulator gasket on the transmission leaking and we replaced that.

I drove the car back, got out and found I have a coolant leak. I just hope the oil and the transmission don't leak again.
 
If this subject comes up from your local service provider just say no.
It seems like a good lesson learned hopefully on time.

Bob Geco
1968 280 SL

[Benz Dr.]

I've never been afraid of synthetic oil. I've used it for over 24 years. That's confidence in a product - AMSOIL.

Daniel G Caron

[Malc]

I have found that if you use mobil 1 in older engines, even ones that have been rebuilt they leak the stuff! It seems to me that the build tolerances are a lot wider in older designs of engines than new ones.
My MGA just ate the stuff and now running it with a good quality 20/50 has stopped munching its way through it.

I guess if a synthetic was made with 20/50W rating it would be good, as synthetics don't break down as fast as traditional oils, but all the synthetics I have seen are 0/30, 0/40 or 5/40. Anybody see anything else? I would like to know.
Malc

[Naj ✝︎]

Malc,
Try Mobil 1 Sport (15w50)
Packing in gold finish as opposed to grey.
Not many people stock it, but some Halfords branches carry it.
If you find an independant motor factor selling 'Comma' products, he could order it for you.
naj

65 230SL
68 280SL

[Douglas]

I've used synthetics (Mobil One) for years with non-rebuilt motors and have never experienced significant leakage issues.

Douglas Kim
New York, NY
280 SL #016220

[Malc]

Thanks Naj

[mdsalemi]

Bob,

So sorry for your Mobil-1 woes.  As a point of fact, after my engine was rebuilt in 2001, it had conventional oil in it; it was changed three times prior to synthetic being installed (original in 2001; again in 2002, again in 2003--Castrol and Valvoline) and with Mobil 1 5W30 this past summer when Dan Caron did the service on it (I bought a case of the oil at Costco).  I have not had any oil leaks.  NOT A DROP.  Dan also uses synthetic transmission fluid as well.

Mobil put on a good presentation on their product at Starfest; I'm sure their technical department would be willing to help you.  I'd be interested to hear what they say and what engine rebuilders besides Dan Caron say about synthetic.  Without putting words in his mouth, I'm sure Dan wouldn't use synthetics if they caused problems.  Mobil recommends the 0W50 even on the old cars, but you have to go to an auto parts store for it.  They don't sell this one at Costco.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[Bob G ✝︎]

Well I am not putting Mobile one down. My ford Mustang uses Red line oil and Red line in the transmission. No leaks ever. On the other hand the engine in my 280SL seems to fine its way out on to the ground. I am going to contact Mobile one and talk to a tech and see what I can learn. But for now not nowing the history of this engine I must be carefull.
Bob Geco

[Raymond]

Malc, I have a case of Mobile 1 15w-50w in my garage right now. (Grey bottle red cap)  I run it in my Acura.  I use the 5w-30w (grey bottle green cap) in my 280SL.  I have no leaks and it doesn't burn any faster than the dino oil.  It is not thinner than dino oil.  That's what those viscosity ratings mean.  I replaced the ATF in the transmission with synthetic--no leaks.  I have read studies about synthetic oil for my airplane and there was a thorough technical article in the MBCA magazine, "THE STAR", a couple of issues back.  There is no reason to fear synthetic oil. It is so superior at moisture precipitation and resisting oxidation and viscosity breakdown that MB now recommends it for all their engines old and new.  The moisture and oxidation virtues are particularly important for an engine that isn't run often.

Bob, I don't know why you are having those sudden leak problems, but I don't believe it's the fault of the oil.

Ray
'68 280SL 4-spd Coupe