Dealer service said synthetic oil will cause my 2003 Subaru to leak.

lokijoker · Jun 27, 2024

SR5 said:
Exactly, we all have our own lives to live, and sometimes that means we get our oil changed at a shop. That's the way life goes sometimes. OP, I hope your medical issues quickly improve.

If the oil filter was on top like newer Subarus I would get a extractor but since I can’t get under a car right now, I have to have someone else do the oil changes.

Thanks, I’m hoping my condition returns to normal, I am slowly improving.

Egg_Head · Jun 27, 2024

Brian123 said:
Your post reminds me of a joke I think I may remember, there are 2 penguins, and 1 of them wants to go get some ice cream, and when the 1 penguin comes out, he has ice cream dripping from his face, and the other penguin says, hey, did you blow a Seal.

No more joking, LOL, but for $29.99 you are not getting a so called Full Synthetic oil, this place is not selling Mobil 1 ESP or Mobil 1 FS for $29.99

John105 · Jun 27, 2024

MParr said:
Service writers or advisors don’t usually know which end is up. On top of that, the so-called deal was a way to get customers in the door.

If one watches the YouTubes about them, we see it’s no different than in an office. They control dollars that techs earn, knowing little to if anything about cars.

pbm · Jun 27, 2024

CKN said:
It's amazing these "Twilight Zone" dealer stories and I haven't experienced any in my life.

I'm missing out.......

I find the whole 'car dealer' business model terrible. No two people pay the same price for the same car.* Salesmen will say anything to make a sale. Window sticker 'add-ons' and 'market adjustment' price hikes above MSRP. Service writers who often push unnecessary service. Service 'check lists' where most items aren't 'checked' etc...
I know Saturn started out with the plan to sell their vehicles for the same price to all but that didn't last for long.

It seems that many car makers are doing what ever they can to make vehicles as non DIY as possible so as to force people into the dealership for service....for example my Fords have no 'access panel' on the bellypan to simplify an oil change like our Mazda does. I have to remove about 10 screws to remove the bellypan just to do an oil change. Also, I've been driving with one lug nut missing for over a year because they did away with the ability to knock out a broken stud which makes replacing a $5 stud into a $300 to $500 job...sad.

I've had a few good experiences at dealerships but the bad ones far outnumber the good ones.
IMO, car dealerships have earned their poor reputation just like shyster lawyers and politicians.

*A widow friend of ours went to buy a new Honda last year and left with their 'best price' but she had to buy it 'that day' to get it. She went back with a male friend a couple of days later and paid over $2000 less for the exact same car.

SC Maintenance · Jun 27, 2024

pbm said:
I find the whole 'car dealer' business model terrible. No two people pay the same price for the same car.* Salesmen will say anything to make a sale. Window sticker 'add-ons' and 'market adjustment' price hikes above MSRP. Service writers who often push unnecessary service. Service 'check lists' where most items aren't 'checked' etc...
I know Saturn started out with the plan to sell their vehicles for the same price to all but that didn't last for long.

It seems that many car makers are doing what ever they can to make vehicles as non DIY as possible so as to force people into the dealership for service....for example my Fords have no 'access panel' on the bellypan to simplify an oil change like our Mazda does. I have to remove about 10 screws to remove the bellypan just to do an oil change. Also, I've been driving with one lug nut missing for over a year because they did away with the ability to knock out a broken stud which makes replacing a $5 stud into a $300 to $500 job...sad.

I've had a few good experiences at dealerships but the bad ones far outnumber the good ones.
IMO, car dealerships have earned their poor reputation just like shyster lawyers and politicians.

*A widow friend of ours went to buy a new Honda last year and left with their 'best price' but she had to buy it 'that day' to get it. She went back with a male fritend a couple of days later and paid over $2000 less for the exact same car.

I 110% agree with you. However the dealer then sends a $29.99 oil change coupon in the mail, and people run on down because the honest local indy guy charges $100.

Sometimes a fool and their money simply need to be parted. There is no free lunch - anywhere.

glen e · Jun 27, 2024

look around your area and on yelp for independant muffler shops. I have one near me that I’ve been using for several years and they are just outstanding. They change my oil with me standing next to the technician and guiding him, I can bring my own oil and my own filter, and they charge me 30 bucks and they take appointments so I’m in and out of there literally within 20 minutes. They also use drive-on ramp type lifts and not forks underneath the car that possibly could be in the wrong spot. important for cars like my current vette. They also write out a complete repair order for the operation, including the mileage, and with the Amzn invoices for the oil and filter, I have complete documentation for warranty purposes.

if anyone is near the Fort Lauderdale area, I use Mad Hatter muffler shop on Dixie, great guys…

joekingcorvette · Jun 27, 2024

Old cars from the 50's to the 80's or newer could leak more with synthetic oil but not so much with the new modern engines.

SumGuy · Jun 27, 2024

This is a fact:

==============
According to TSB DL003-03 Toyota Genuine Synthetic Differential Gear Oil (P/N 00289-75140) cannot be used in 2000-2002 Tundra vehicles and 2001-2002 Sequoia vehicles. The rear axle oil seals are not compatible and will leak if synthetic differential gear oils are used.

Toyota does not have a position regarding the use of non-Toyota Genuine Synthetic Differential Gear Oil as we do not require its use. If you do use synthetic gear oil Toyota recommends that you do not switch back and forth between regular and synthetic and that you research its compatability with the maker.
===============

In discussing this Toyota issue, some people wrote about different chemistries involved in seals and how that could or does play a role:

=============
In regard to synthetic oils, Mobil 1 is made from polyethylene glycol. This oil is rarely safe to use because of incompatibility issues with seals. However, Amsoil is made from a Diester, which is a vegetable base and is quite compatible with all your toyota seals. You won't have any issues if you use a Diester based synthetic oil.
=============

Was there a change from rubber or silicone to viton seals 20 years ago?

"However, silicone rubber does not have the same level of resistance to petroleum-based fluids as viton does."

https://suconvey.com/silicone-rubber-and-viton-whats-the-difference/

kschachn · Jun 27, 2024

ka9mnx · Jun 27, 2024

joekingcorvette said:
Old cars from the 50's to the 80's or newer could leak more with synthetic oil but not so much with the new modern engines.

In the 70's I used, the original, M1 in my rebuilt '58 Ford I6 engine. Have used M1 since with no oil seal/gasket issues.

joekingcorvette · Jun 27, 2024

That's true ka9mnx and it can work without issues. I do know of several instances where synthetic oil would leak out of engines and regular oil would not leak as much. A friend of mine worked in a station where they did a lot of oil changes and it happened frequently with older engines. Newer engines are made for synthetic oil and the older engines had gaskets that were not as good as what you can get today. Lot's of show cars don't even have oil in them because they leak on the showroom floors.

joekingcorvette · Jun 27, 2024

A 2003 Subaru is new enough where it shouldn't matter if synthetic oils are used and it should leak the same as regular oil.

barryh · Jun 27, 2024

joekingcorvette said:
A 2003 Subaru is new enough where it shouldn't matter if synthetic oils are used and it should leak the same as regular oil.

I like the above as the most realistic answer.

I'm running a 45 year old BMW motorcycle on "synthetic" oil and of course it mists a little oil but no more than in did on non synthetic oil.

To say using synthetic oils on old vehicles always causes leaks is nonsense not least because most oil marketed as synthetics, isn't.

I'd have more sympathy for a view that said high detergent oils may cause leaks in old vehicles that have been run on non detergent oil because that would be much nearer the truth.

You know what they say about old wives tales - even if they are not true it takes multiple generations for them to die out so we are stuck with this one for a good while yet.

Trav · Jun 27, 2024

barryh said:
I like the above as the most realistic answer.

I'm running a 45 year old BMW motorcycle on "synthetic" oil and of course it mists a little oil but no more than in did on non synthetic oil.

To say using synthetic oils on old vehicles always causes leaks is nonsense not least because most oil marketed as synthetics, isn't.

I'd have more sympathy for a view that said high detergent oils may cause leaks in old vehicles that have been run on non detergent oil because that would be much nearer the truth.

You know what they say about old wives tales - even if they are not true it takes multiple generations for them to die out so we are stuck with this one for a good while yet.

You cannot compare an old BMW airhead engine to a Subaru engine, the air head is not a split case sealed with RTV, try it on a old brit bike or VW air boxer.

Hall · Jun 27, 2024

Lubener said:
For $29.99 why not?

True, just have to be prepared to say "no, thanks" to all of the other stuff they try to upsell.

taintedtattoo · Jun 27, 2024

IF your worried about it, use high milage synthetic oil, It contains seal swellers and will help with any minor leaks.

ARCOgraphite · Jun 27, 2024

"Fully Synthetic" is a marketing term. Unless it's a very high specific output engine with a special approval required, use "SS" or "Conventional" They are likely both grp II, III blends and meet SN/SP and ILSAC.

Someone point me to a "classic definition" true synthetic oil that is ILSAC and Resource Conserving from a major that I can purchase at Walmart or Autozone. I am aware of none.

kschachn · Jun 27, 2024

Hydrocracked Group III base stocks are synthesized all day long. You assemble the base from intermediates, not just purify the existing molecules.

It’s the classic definition whether you think so or not.

cb_13 · Jun 27, 2024

John105 said:
If one watches the YouTubes about them, we see it’s no different than in an office. They control dollars that techs earn, knowing little to if anything about cars.

Weird. I spent 10 years as a tech before I moved to the desk. I must have been a terrible tech all that time, knowing little to anything about cars and all

I later found the best position in the automotive industry is out of it!

wsar10 · Jun 27, 2024

lokijoker said:
The Subaru dealership near me is running a deal for a full synthetic oil change for $29.99. When I called to make an appointment for my low mileage (46k) 2003 Legacy, the advisor told me that because of its age, they would only recommend conventional oil because synthetic would cause the seals and gaskets to leak. Is that valid advice? The car has never had synthetic oil. It’s either only had conventional and maybe synthetic blend. The car belonged to my Dad and he had all the oil changes at the dealership.

I would not go back to that dealership..... Its sounds like they try to sway customers decisions based on unfounded personal opinions, and this happens allot.

Having said that, I have been in your situation before and did a gradual change. I have seen other Subaru's with a life diets of DINO then they go straight to a high quality synthetic and all H#LL breaks loose if the engine has any kind of sludge or issues. I have seen cam phaser solenoid screens get clogged, timing chain tensioner galleys and much more. Whereas if you make a gradual change instead of "shocking" the system, you still clean things up but it happens at a reasonable pace.

I always recommend people going to high mileage DINO, then a syn blend before settling on your final choice. Remember that synthetics are NOT necessarily an "upgrade"... It's about application and preference. I would have no issue running a solid DINO in that car and doing shorter OCI's, or sticking with something like Valvoline ML even at the low mileage as age is still a factor.

My $0.02

Dealer service said synthetic oil will cause my 2003 Subaru to leak.

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