About synthetic oil and high milage engines..
Moderators: Helpinators, Moderators
About synthetic oil and high milage engines..
So I'm considering getting some Motul Synthetic for my car. Figure might as well go for the best stuff.
My car is a 1994 Leg Turbo with 420,000km's on it. Would synthetic be a good or bad thing, comparet to dinosaur snot ?
Thanks.
My car is a 1994 Leg Turbo with 420,000km's on it. Would synthetic be a good or bad thing, comparet to dinosaur snot ?
Thanks.
-----
http://www.bignose.ca/legacy/pics/
http://www.bignose.ca/legacy/pics/
-
- Knowledgeable
- Posts: 1770
- Joined: Mon Dec 16, 2002 3:20 pm
- Location: Owings Mills, MD
- Contact:
Bad. I've heard that synthetic oils tend to have detergents in them which clean out deposits from dino oil. These deposits tend to seal up old seals . . . take those deposits away and your engine starts leaking.
Of course, if you change all of the seals anyway, then you can disregard what I just told you.
Of course, if you change all of the seals anyway, then you can disregard what I just told you.
[url=http://www.angelfire.com/md3/91turbolegacy/images/On_the_Lawn.jpg]1991 Legacy Turbo (RIP)[/url]
[url=http://www.angelfire.com/md3/91turbolegacy/images/Summer_Car_Wash3.jpg]2000 Celica GT-S[/url]
[url=http://www.angelfire.com/md3/91turbolegacy/images/Summer_Car_Wash3.jpg]2000 Celica GT-S[/url]
Motul...really? I've heard people running the brake fluid, but it seems most subaru types going with really good synthetics choose either redline or amsoil. I'd go with redline myself, but my car was always run with amsoil by the previous owner, so I kinda think I should stick with it.
Good luck
Micum
Good luck
Micum
Micum
91 Legacy Turbo Sport - 94 JDM EJ20G
97 Legacy 2.5 GT - mod'd
93 Impreza L AWD (sold)
97 Legacy 2.5 GT (deceased)
98 Legacy Outback (sold)
91 Legacy Turbo Sport - 94 JDM EJ20G
97 Legacy 2.5 GT - mod'd
93 Impreza L AWD (sold)
97 Legacy 2.5 GT (deceased)
98 Legacy Outback (sold)
I don't know about Subarus, but Moto Guzzi's have a bad tendency to leak when you switch from dino to synthetic oil. Not terrible leaks, but seeps that weren't there before. If dino is doing fine, why change? Unless you're changing all the seals and rings, then you're likely to develop leaks. You'll notice lower oil pressure, and your engine will start to use oil. The cons outweigh the pros, IMHO. Of course, YMMV.
Rob
Rob
-
- quasi-mod-o
- Posts: 6000
- Joined: Thu Dec 05, 2002 7:06 pm
- Location: Tampa, FL
It's not the synthetic part of the switch that's the problem, it's the fact that you're switching brands of oil. Each brand of oil has its own additives. After a few oil changes, those additives build themselves up on the various seals. When you switch brands, the additives in the new oil strip away the old additives and take time to build their own back up...
The fact that synthetic is slightly thinner than dino doesn't exactly help, but that's not the major problem...
The fact that synthetic is slightly thinner than dino doesn't exactly help, but that's not the major problem...
2000 Subaru Legacy B4 RSK
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
The reason you can get leaks when you switch from dino to synthetic has no bearing on oil type/brand, etc.
Synthetic oil is an extremely good cleaning agent. Much more so then dino oil. So what happens is if your engine has lots of miles on it, and the seals have gotten slightly bigger, the dino oil has probably sludged up in it to help seal. When you put synthetic in there, it breaks down the sludge, voila, oil leak. Replace seal, and oil leak goes away.
Synthetic oil is an extremely good cleaning agent. Much more so then dino oil. So what happens is if your engine has lots of miles on it, and the seals have gotten slightly bigger, the dino oil has probably sludged up in it to help seal. When you put synthetic in there, it breaks down the sludge, voila, oil leak. Replace seal, and oil leak goes away.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
iirc something like an hour labor at a mechanic, the seals that usually go are the crank and cam seals, and i don't believe the seals are over $30 for the lot.
MK
MK
Last edited by mTk on Sat Jun 07, 2003 7:29 am, edited 2 times in total.
1992 BC672 AWD 5MT
Please let us know the address of the ata mechanic I think it would pay me to drive to IL from Denver to have the work done. One thing about syn oils that we found out years ago on Porsche's was that the syn oils were thinner at low temperatures and the oil would leak past the rings and would get into the chamber and burn on start up and the same holds true for the Subie engine. A good oil such as Shell Rotella or other premium oil is probably the best bet for older engines because of the potential problems mentioned above and a few others that are a little lenghthy to go into such as that some deposits will at times form a "seal" in very small areas and the use of a very high dertergent oil can open these.
AL(CO)
al@iwtu.net
AL(CO)
al@iwtu.net