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.
Dealer service said synthetic oil will cause my 2003 Subaru to leak.
- Thread starter lokijoker
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You can still get oil labeled as "conventional" in 10W-30. There are a few brands around. Valvoline, Castrol GTX, Napa has some in their bottles. Its about the same price as syn, but I am currently running it in the Xterra in my footer, primarily because I got it cheap on clearance.
The Xterra was interesting in that it ran conventional its whole life, and for quite a while the valve covers leaked (normal on those). Before I fixed them, I tried a couple different brands of semi-syn. Castrol GTX semi syn leaked the worst. QS 5w-30 and Chevron Supreme 5w-30 were much better. The Chevron SDS says "Highly refined mineral oil (C15 - C50) Mixture 70 - 99 % weight" so who knows how much "synthetic" your getting, and what type it is? But it worked pretty well in my case.
The Xterra was interesting in that it ran conventional its whole life, and for quite a while the valve covers leaked (normal on those). Before I fixed them, I tried a couple different brands of semi-syn. Castrol GTX semi syn leaked the worst. QS 5w-30 and Chevron Supreme 5w-30 were much better. The Chevron SDS says "Highly refined mineral oil (C15 - C50) Mixture 70 - 99 % weight" so who knows how much "synthetic" your getting, and what type it is? But it worked pretty well in my case.
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If you're only planning on doing this oil change the one time I would skip it and use whatever you normally do. As someone else said, if it ain't broke..
On a side note I never change brands for our two vehicles - Always use Valvoline semi-syn in my ancient Miata, and Castrol in my wife's late model BMW. Both vehicles are done for us at their respective shops. I sometimes use a different weight in my car if they're out of the usual, but mixing brands of oil is strange to me and i never do it. I can't back it up scientifically but I think it's better to stick to one brand of oil over a car's lifetime, rather than willy nilly putting in whatever you can scrounge up. I realize others will disagree with this opinion.
On a side note I never change brands for our two vehicles - Always use Valvoline semi-syn in my ancient Miata, and Castrol in my wife's late model BMW. Both vehicles are done for us at their respective shops. I sometimes use a different weight in my car if they're out of the usual, but mixing brands of oil is strange to me and i never do it. I can't back it up scientifically but I think it's better to stick to one brand of oil over a car's lifetime, rather than willy nilly putting in whatever you can scrounge up. I realize others will disagree with this opinion.
There is some truth to what they told you with these engines, these engines use a split engine case sealed with RTV. Many RTV sealers do not deal well with esters commonly found in synthetic oils and leak sealers, most grp III synthetics should be a non issue but just out of caution I would stay away from high end synthetics and high mileage oils that use seal swellers.
Bait and Switch.
Insist on the Synthetic.
Despite what others in the forum say, your dealer may just have something there. I had a 1995 Honda sedan then, manual transmission, 70K miles, always had dino oil. In 2005, decided to use Mag 10W-30 Fully Synthetic, which was made of mostly Grp III oil. 5 days after the oil change, I saw oil droplets on my garage floor, just below where the flywheel part of the car when it is parked. Rear main seal, I surmised. I removed most of the oil with a vacuum pump through the dipstick tube, then replaced with dino Shell 15W-40, and the leak disappeared. From then on, I always used dino oil and the leak never returned. I sold that car 4 years later.
My '97 Explorer started leaking oil at around 297k miles. Steady diet of syn oil since 0 miles. Maybe the life of the seals was compromised by the syn oil. I'll take it to the dealer who will fix the leak by going back to conventional.
I don't want to overthink this.
I don't want to overthink this.
Oil leaks after an oil change can also be from the drain plug, oil filter, and from personal experience the oil pressure sending unit.
I was sure the leak came from the new oil, wrong! The sending unit failed.
Today I run the called for grade of motorcraft blend in the family cars and call it done.
I was sure the leak came from the new oil, wrong! The sending unit failed.
Today I run the called for grade of motorcraft blend in the family cars and call it done.
back in the 70s, I had a six-year-old Fiat X19. I was all excited to try this new oil called mobile 1 so I went out and bought the appropriate amount and a new filter and changed over. The engine leaked like a sieve all over my garage floor… At that point, no one knew exactly why it did it, because synthetic was so new. So I just put up with it for awhile but sold the car six months later.
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I did have a questionable timing cover reseal start leaking after using an oil that was high in ester content.
Those X19s were like spaceships back in the day. What were they like to own and drive?
OP I switch between conventional and synthetic all the time. No problems for me. Maybe an elite PAO & ester synthetic could mobilise some of the old grime. But the modern cheap Group III synthetic is so chemically close to a Group II heavily refined mineral oil, that I couldn’t see it making a difference.
For $29.99 why not?
I’m guessing this is a loss leader to get people in the door and try to upsell them on more expensive repairs. I totally know this game and have experienced it. I just thank them for letting me know about all the “repairs” that are needed and that I will make an appointment the next week and then I don’t do it.
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I don't think it would. I went to full synth on my 1998 Maxima when it reached 200k. I did think about leaks, but determined this was when seals were different, so we'd have to go back to even older cars, not a 1998, not a 2003. With this being said, watch the OP switch and his car begins to leak lol
Due to recent medical issues, I can’t get under a car to change oil myself so I’m going to have to take it somewhere to change the oil. I got this offer in the mail from Autonation Subaru and it looks like a good deal even if it’s for conventional oil but for full synthetic oil, it’s a really good deal if they really fill it with synthetic oil. Best deal I’ve seen even for conventional oil.
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.
You have done enough work to see the stringy rubbery mess from oil deteriorated RTV. Years ago on air boxers we used Curil T but newer products like Loctite 574 out perform it by a wide margin. I have no idea why Subaru still uses RTV on the cases and oil pump, it has caused huge problems with breaking free and wiping out the main bearings and leaking, the other consequence of RTV is the increase in bearing clearance resulting in lower hot oil pressure, the 574 eliminates all this on these applications and never leaks.
For all other hard flanges Hylomar M works great and is impervious to esters also, neither will plug an oil passage like RTV.
I guess that’s what I’m asking. My Dad found the car in 2010 with only 10k miles on it. It had been traded in by an old man who literally only drove it to church and the grocery store. It the records that it had all its oil changes at the dealership every 3.5k miles. When my Dad bought it, the dealer through in a punch card with several free oil changes and after he used them up he did the oil changes himself until he couldn’t anymore then started going back to the dealer. I’ve inherited the car but due to a physical disability, I can’t change the oil myself right now. If it’s true that synthetic oil could make it leak, I’ll stick with conventional. I have a 2008 Honda Element that I had all the oil changes at the dealer with synthetic blend. The dealer had a separate quick lube location with reasonable price and if you did your oil changes with them, you got a 10 year, 100k mile powertrain warranty. Once I passed the 10 year mark, I started changing the oil myself and I switched to full synthetic with no issues.