Alan G.

Jet,

Why not just replace the valve cover nut with a new one. Or throw down $20 for a new valve cover gasket set. I spent about 8 hours changing my crank seal, and valve cover gaskets (and valve adj), and about 4 hours replacing the sending unit( the hard way) to stop leaks but I'll stick with Mobil 1.

Clipboard

Hi. Just my 2cts since I think this is a valuable forum. In the day, I managed a Porsche 944/944S/944S2 IMSA team. We used Mobil 1.
At Sebring one year a rent-a-driver backed into a tyre barrier - not too hard, but hard enough that masses moved and the top water hose was nicked by the alternator fan. That car ran to the end of the race (nearly 55 minutes) with no water and the temp guage pegged. Yes, Mr Motronic went to the default setting of full rich and some wiring melted, but she lasted.
We rebuilt each engine every 12+/- hours running time (except, of course for the 24hrs of Watkins engines). Before tear-down, the oil was drained thru a cheese cloth and the oil filter cut open. After the engine rebuild (and dyno break-in with 30wt non-detergant ElCheapo from the 7-Eleven), the used Mobil 1 was put back in.
I ran Mobil 1 for years in my little 86 Mazda p/u (it's still running for another owner), I run it in my 90 Q-ship, and I'll run it in the SC.
I know it finds places to seep - we knew it going in from the Mobil rep.
That's all - just anecdotes.
john

reed

Just curious why no one seems to use the Mobil 1 0W-40. I think it has been the factory fill for awhile now and has the best range of any of the Mobil 1s.

sschmerg

According to the Mobil 1 web page, the 0W-40 is primarily for "newer" European cars. The 15W-50 is the "race-proven" formula "that provides superior high-temperature protection for high-performance cars." It is also "The highest viscosity Mobil 1 available."

So it seems for hard driving and racing, you want the 15W-50.

-Sean

JPhillips-998

No JLKline, my leaks were not nearly that bad. Basically from the case seals. While I agree a leaky engine is not the most ideal or attractive situation, it's still the inside that counts. I can't take credit for the idea of the minimal oil leaks being okay. That came from a very well respected (LeMans, Sebring) race team owner and mechanic. I will admit that I might be a little biased b/c I have 4 cases of the stuff on my shelves.

Porschephanatic

It has been my experience that Mobil 1 did cause leaks in my SC, but the benefits far out-weigh negatives. My '91 Capri XR2 turbo, that I bought new, and have used Mobil 1 exclusively in, has 186,000 miles on it, w/out a turbo or engine rebuild! It still has unbeleivable power (for 1.6 liters) and LOW oil consumption. I swear by it. I even use it in(on) a 1926 Lawson hit-n-miss. Now if someone could develop gaskets for my 3.0 that are compatible w/ Mobil 1 ...... <img border="0" title="" alt="[Wink]" src="wink.gif" />

jlkline

I guess its about the degree of tolerance in many cases. I'd probably M1 in a strictly track car, but not for my daily driver. Oil burning on the heat exchangers and drips on the floor don't accurately reflect the level of time/care (and Porsche engineering) put into this car.

I think its also a good rationalization that these earlier engines were designed to run on dino oil, and have repeatedly demonstrated their longevity and endurance without synthetic, easily going upwards of 150K-200K miles before rebuilding is required. I figure even if I keep it and drive it daily for another 150K miles, I'm sure I'll be ready for something more exotic under the lid when this rebuild gets too long in the tooth.

That said, if a synthetic was available with a proven record of not leaking, I'd be all over it.

alan911sc

There was a response on the PCA tech site about an unconfirmed report of the shape of the molecules of Mobil 1. It said something to the effect that their shape made them more slippery and allowed it to pass sealed areas more easily,thus contributing to leakage on older models. I think it was in the 964,993,996 section.It also stated switching back to dino oil cured the problem.

alan911sc

It's listed in the 964,993,996 section under "964 Oil Leak. Molecules of synthetic are longer and thinner than fossil fuel oils.

bship

This probably sounds stupid but what would happen if you mixed M1 and dino. Does it make sense that they could be mixed to benefit from each others characteristics or would they stay seperated?