Synthetic Leaks

[MalMac 1,328]

I know the battle of synthetic vs. conventional oil has been discussed here over and over. I don't want to open that can of worms again. What I do want to ask is can switching from conventional oil to synthetic cause seals to start leaking? I have heard this numerous of times. Has anyone had this happen? I would like to here from members that have switch and the results they got as far as leaks occurring. The motors I am thinking of switching over have anywhere from 200hrs to 800 hrs on them.

[just me 0]

I have heard of this but personaly have not seen it. all my tractors and vehicles have synthetic or a blend in them. They leak no more or less with either

but all my junk has 1000 hrs + or 150000 + miles they leak like an old persons bladder

[DMK855 15]

I have not seen it proven!! An oil leak is an oil leak, and it is going to leak no matter what oil is in it!! Just my opinion!!

[smoreau 658]

I have not seen it proven!! An oil leak is an oil leak, and it is going to leak no matter what oil is in it!! Just my opinion!!

I agree. :banghead:

[rmaynard 14,932]

I have not experienced it on a single cylinder engine because I always use conventional oil in them, but years ago (1980's), I worked for a company that had a fleet of VW Beetles as service vehicles. All of these cars had at least 60,000 miles on them when the owner decided to try Mobil 1. They all leaked like a sieve.

Needless to say, he went back to conventional.

Bob

[Giles 2]

Why take the chance? A few years ago, it was not recommended to change from petrolium to synthetic, or vice-versa, because of different "oil swell properties" of the different oils.

As far as I am concerned, I still go by this recommendations. I guess some people have done the change with no problems.

I don't even mix different brands of petrolium oil or different weight oils, but I never use an oil additive either.

[rick 217]

Regarding the leaking seals after a change to synthetic lube- one school of thought is that the superior cleaning qualities of synthetic lubricants removes the varnish and sludge buildup on the shaft on the inside lip of the seal, thereby allowing the worn seal to leak.

Would I change the oil in my 698 hour Onan to synthetic? No, but I plan to change the Eaton 1100 to synthetic. That is, unless someone has had a bad experience doing the same and advises against it. After using petroleum oil in the REBUILT Briggs engine on my C111 to break it in, I switched to 10W30 synthetic oil with no problems.

Kohler doesn't recommend multi weight oil for K engines, so I will leave conventional oil in the REBUILT K241 on my C100.

[zieg72 209]

Two experiences several years ago, both on car engines. One was an Amsoil dealer who had a Toyota that had a lot of miles, engine leaked like a sieve. Same issue with folks switching to Mobil 1. I was always under the impression that the oil was really thin and that was the reason. I was thinking of a synthetic blend for the 520H next oil change.

[Forest Road 594]

I switched over to Amsoil in a Toyota Tundra w/ 80,000 miles. Within a couple weeks I had a very slight drip from the rear main. Within a month or so there was no more leak. When I spoke w/ Amsoil tech line they told me that this MIGHT happen. I drove the truck for another 2 years and 30,000 miles without anymore leaks. I also run it my wife's minivan and next month in a new F 150.

I'll be switching both of my Kohlers and an Eaton 1100 to Amsoil this summer. I run my machines less than 25 hours a year so I'd like to change the oil once a year. With Amsoil I feel comfortable doing that.

For the record I am NOT an Amsoil dealer. Just one very happy customer.