There were a couple of types of Synthetic when the whole fad started circa 1975. There were a couple dozen Synthetic motor oils around in the late 1970s, many with names you hadn't heard of before or since.
Most, like M1, were POE. I forget what the others (All-Proof?) were made of. Initially, M1 caused shrunken rubber seals and leaks. Then Mobil added some seal swelling additives, and it caused soft swollen seals, and you got the leaks when you quit using it. By 1980 or so, Mobil had it straightened out, but I can't guarantee everybody did. But I'm sure anything really out of whack was off the market by 1990. > On April 24, 2017 at 7:38 PM Curt Raymond via Mercedes > <mercedes@okiebenz.com> wrote: > > > Yup and that's been my experience too. Somebody said that early synthetic > (like the 1980s) didn't have the seal swelling agents the new stuff has so as > crud got cleaned away leaks appeared that never sealed. > Curt > > Sent from Yahoo Mail on Android > > On Mon, Apr 24, 2017 at 11:47 AM, Randy Bennell via > Mercedes<mercedes@okiebenz.com> wrote: I have a vague recollection that > Marshall Booth said that switching to > synthetic oil might make an engine leak more at the outset, but that it > would be fine after some time. > Anyone else recall this or am I lost in space? > > RB > > On 23/04/2017 11:53 PM, rogerhga--- via Mercedes wrote: > > Curt, > > When I got my Dodge, it was an off lease that had roughly 100,000 miles. It > > had been run with dino 10w30, forget the brand. I switched it to Valvoline > > Maxlife 10w40 for engines with over 75K. Both main seals were dry and I > > wanted to keep it that way. But I was tempted at one point and put in Mobil > > synthetic. As I said, it did not turn out well, but switching back to > > Valvoline stopped the leaks. I change oil and filter on the truck and both > > diesels around 3-3.5K miles. The Escape using Mobil synthetic I change at > > 7500. It uses 1 to 1.5 quarts between change, burns some I guess and leaks > > some from the valve covers. I asked the Ford dealership about running a > > thicker oil, but I was told the oil ports in the 3.0 V6 are too small to > > risk running a thicker oil. I think it uses 5w20 or 0w20, can't remember > > right off. > > My 83 300D has a block heater, but being in the South, I've only used it > > once or twice in 20+ years. For some reason, the 300D will start faster at > > colder temps than the 300SD even though they have basically the same 617 > > engine. > > Best Wishes, > > Roger > > Roger Hale > > Dinnerware Classics, Inc. > > Monroe, Ga. > > 770-267-0850 > > www.dinnerwareclassics.com > > > > > > _______________________________________ > > > > > > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
