max808

i have 50k miles on my max and no oil leakage or consumption. i'm thinking about changing to synthetic, but heard some post that it's not recommended for higher milage cars. something about seal leakage. when did you change to synthetic and have you experienced any leaks?

Kevin Wong

I heard it was the opposite. I thought you were supposed to put a few thousand miles on the car before switching to synthetic. The seals have to be worn in with the normal mineral oil because the synthetic is too smooth and will leak through. I started using synthetic motor oil around 8K miles and have about 50K miles now. I plan on using if until the end. After looking at the oil analysis sheets from Bill, I change my oil every 10 months or so at 10K miles. I have my own oil analysis kit that's waiting for a sample the next time I change. I have 9K miles on this batch.

iwannabmw

iTrader: (3)

The seal issue was an old one and no longer applies, though it still circulates in rumors. When synthetics were first introduced they lacked the aromatic compounds that dyno oil had, which tended to allow the seals to dry up and shrink a little, causing leaks. Synthetics on the market today are made with additive packages that makes this problem obsolete. If you have no problems with your car now, switching to synthetics won't cause any.

max808

mobile 1 web site says the same thing, it only happened in older cars. except they say it was the type of seals used in older cars, eg. 70-80's.

maximus75

iTrader: (5)

iwannbmw is correct. Leakage problems associated w/ synthetic oil are a myth. They no longer apply to the synthetic oils used today. Keep in mind that sythetic oil is less viscous than organic oil even if it has the same weight designation so don't go too thin. I use 10w30 Mobile one and I have 36k on my car.

perfectmax

iTrader: (1)

No leaks and I recently switched to synthetic oil around 60,000 miles and had no leaks for a good month or so. Now after a few months oil is dripping out of my car all of the time. Its aweful. Nissan said it was the rear main seal =$$$. So, I just switched back and it is still leaking out. I guess that i just need to bite the bullet and fix the car. I'm just trying to figure out whether it is my fault in just driving the car hard or if switching to synthetic accelerated the leak (srunk the gasket). Any ideas? Also, anyway around spending a looooooot of $ to fix this??

exhip95

I switched to synth at about 65,000 miles. I now have 109,000 miles and have had no problems whatsoever. I live in Florida (hot as **** in the summer) and prefer Amsoil 10w-40. Even after driving 8,000 to 10,000 miles between changes I have never noticed any oil loss.

got rice?

iTrader: (2)

Not entirely true. Vehicles previously using dino oil would build up sludge around the seals. If the seals themselves were bad, the dino oil can provide enough blockage and no leak would be present but once the switch to synthetic is made, the sludge breaks up making the new oil to leak through the seal. No fault to the syn. oil but the fault of the seal.

gsleve

if you're seal is leaking with such low mileage its and indicator that the last owner did not change the oil in a timely manner hence dirt and varnish has covered the seal, however if while using a synthetic oil there are a lot of detergents in this oil inherently that allows for keeping the motor clean thereby doing it's job that the original failed in part to do, once the varnish is removed by the cleaning properties of the synthetic in time with mileage about 500 miles or so this leak stops because it now is reexpposed to the oil that hence allowing it to swell back to it's designed position, the previous dino oil starved the gasket or seal of oil and created a false seal through the varnish now once seal is exposed time has to elapse so that the seal can reswell again. don't be to hasty to blame the synthetic for doing it's job blame the dino oil it caused the problem in the firt place preventing the seal for exposed oil given that the oil oxidized from time to time and created varnish synthetics just keep clean and maintain cleanliness within the motor

iwannabmw

iTrader: (3)

The synthetic will not shrink the seal. What gsleve mentioned is right on target, although it's not always that the synthetic oil will penetrate the seal and allow it to swell up again in order to completely stop the leak.