Starting to use synthetic oil

00ls1bird · 02-17-2006, 05:05 PM

I was talking to a mechanic and was told that changing to synthetic oil can make gaskets leak in higher mileage engines. Is this true and is 23000 miles too much to begin using synthetic or at least a blend?

**blackSS01** · 02-17-2006, 05:15 PM

23000 is fine to change to syn fluids. High miles would be about 100,000. The reason is that syn is thinner then dino oil and after many miles the gaskets don't seal as good, hence the leak. You'll be fine, enjoy the mpg and hp.

**SeVeReDiStOrTiOn** · 02-17-2006, 05:20 PM

I put in synthetic at 79,000 (not original owner) and no leaks [knock on wood]

**02z28ls1** · 02-17-2006, 08:04 PM

The leak thing was true back when synthetics were introduced back in the 70s.It's no longer a concern w/a modern synthetic.

00ls1bird · 02-17-2006, 08:25 PM

Awesome...I still have another 2600 miles to go but then its synthetic all the way. Any recomendations on brand? I always used Mobil on my stang.

**oneBADDz** · 02-17-2006, 08:28 PM

Mobil 1 and believe it or not quaker state full synthetic is VERY good oil

**ocshaman** · 02-17-2006, 09:41 PM

Syns cause leaks because they will clean up false seals caused by dirt and sludge, not because they are necessarily thinner or slicker.

**02z28ls1** · 02-17-2006, 11:25 PM

From what I read in various publications-that's no longer true.That's what used to be true-but that was 20+years ago.

**~redlinels1~** · 02-18-2006, 07:37 PM

I use Mobil 1 and love it. German Castrol is awesome but pretty hard to find.

**Sarge** · 02-19-2006, 10:07 AM

Originally Posted by ocshaman

Syns cause leaks because they will clean up false seals caused by dirt and sludge, not because they are necessarily thinner or slicker.

Ding ding ding ding...we gotta a winner....Ichiban for sure....
Synthetics will clean the sludge seals caused bu oils lacking the cleaning packs found in synthetics and folks believe the oil is thinner or is causing the leaks....no...it cleaned the sludge wall from your seals and now they leak....replace the seal....more than likely though you will have no issues as dino oils of the past few years ( SL API ) have good cleaning packs...so this is becoming a thing of the past....