Oil Changes and Suby Engine Life ...

[Mako Koiwai]

As you all know, Karen's '06 Turbo Legacy Outback is on basically it's third engine (third rebuild required a new short block). All the work has been done under warranty. The car is just a fwy daily driver. Timmon's Subaru recommended that we NOW change the oil every 3K.

We've been doing that ... but do you really think that is necessary. Going by the 3K changes, we need another change ... but the oil is very clear and light colored still. Those extra oil changes are out of our pocket.

The thing is is that sometimes the engine gives off a very hot oily smell ... noticeable when one steps out of the car ... after just a normal freeway drive (driving back from Santa Barbara in the rain for instance). But not always?

The new engine is NOT using any oil, and as I said, after 3K is still very clear and golden.

Normally one would think that with a new engine we should just keep the car for DD'ing. But we're worried. We're trying to put a lot of miles on the car, so that if something happens, it happens under the latest 1 year warranty. The last engine blew just a week before it's warranty was up!

So ... go by what the garage is saying on oil changes ... or do what Subaru of America says, ie. oil changes at 6K ... and hope if it goes, it goes within a year again ...

[Jeff Shyu]

the 3k mile / 3 month guideline is, and has always been a terrible gauge for oil change.

i've lived by the "check the engine every time you fill up, when it gets to be dark brown, change it."

[Daniel Y.]

http://www.blackstone-labs.com/" onclick="window.open(this.href);return false;

Pretty much the only way to figure out what's really going on.

FWIW, I started with dino oil on my WRX, every 3,750 with filter. At 15k, I switched to synthetic at 5k intervals. I've always consumed about a quart between changes regardless. 130k hard miles later, it's still running strong.

[Kurt Rahn]

Since it's got a fresh engine, I think I'd just sell the car and get something more reliable.

[Mako Koiwai]

I think that's what Karen wants to do ... get a tow truck.

[Steve Towers]

This may be a deja vu post, but I'll do it anyway. A couple of years ago Consumer Reports did an article on oil change mileage requirements. For the test they used New York City taxi cabs, vehicles they considered to be at the high end of the abuse spectrum. They did engine teardowns, lab analysis on the oil, and other stuff. I don't have the article, but I recall the conclusion was changing at 7500 miles was sufficient for the cabs and that most folks could go beyond that without any problems. Since then, that's what I do for my cars (also satisfies warranty on my '09 Sienna) without any issues. Possibly different in extreme conditions but we don't have those locally.

'99 Sienna (200k miles) and 2000 Corvette are fine with 7500 mile intervals.

My belief: oil changes at 3k miles are a marketing thing with folks that sell the oil. Not needed.

[Will Kalman]

My belief: oil changes at 3k miles are a marketing thing with folks that sell the oil. Not needed.

I agree. I replace the oil in my cars at the recommended intervals with synthetic oil. That meets manufacturer requirements and gives me comfortable overkill (my cars don't require synthetic).

As for Mako's engine woes and oil recommendations - any engine that requires perfectly pristine oil to avoid destruction in normal driving is a complete engineering failure.

[Mako Koiwai]

Thanks guys ... the Outback isn't using any oil, but it sure uses a lot of gas. The Suby Turbo is known for being thirsty ... but it seems like we're down to 21 mpg on the fwy?! On our 5,000 plus mile trip to Canada in September we averaged 23 mpg ... which I thought was pretty bad for a lot of fwy cruising using the Cruise Control at typically 74 mph. Going up to Santa Barbara and back, in pouring rain, we only got 21 ?!

Engine doesn't feel "tight" ... rev's cleanly and easily. The rebuilt engine has about 10K on it. Tire pressures are up. I actually pumped them a few lbs over for the Canadian trip. Alignment is right on.

[Bob Beamesderfer]

the 3k mile / 3 month guideline is, and has always been a terrible gauge for oil change.

i've lived by the "check the engine every time you fill up, when it gets to be dark brown, change it."

That's no better than 3k mile.

[Bob Beamesderfer]

I'd sell it or trade at a non-Subie dealer that can't see all the warranty work done.

[Arthur Grant]

I'd sell it or trade at a non-Subie dealer that can't see all the warranty work done.

Not true, CARFAX has ended the day were you can't see every dealer service.

Having said that I would get rid of any car I had to worry that much about. Since Karen is going track racing with the miata, a truck is almost a necessity, but if you think 21 mpg is bad??????.

I understand the oil change is out of pocket but really? $20 bucks at lube shack with a coupon or about the same at Wally Mart. If the dealer told you every 3k I would do that until I am out of warranty and I would have someone do it so I had a receipt. I have 6 cars, all get changed every 3,500 miles. Cheap insurance. The Vette gets Mobile One which is all it has ever seen, the rest get the oil dejour. I have 5 free oil changes form the new local Hyundai dealer, and for the others they go to my mechanic, who charges me $25.

[Robert Puertas]

Thanks guys ... the Outback isn't using any oil, but it sure uses a lot of gas. The Suby Turbo is known for being thirsty ... but it seems like we're down to 21 mpg on the fwy?! On our 5,000 plus mile trip to Canada in September we averaged 23 mpg ... which I thought was pretty bad for a lot of fwy cruising using the Cruise Control at typically 74 mph. Going up to Santa Barbara and back, in pouring rain, we only got 21 ?!

Engine doesn't feel "tight" ... rev's cleanly and easily. The rebuilt engine has about 10K on it. Tire pressures are up. I actually pumped them a few lbs over for the Canadian trip. Alignment is right on.

Jill's Tribeca get's about 17 on the hwy. 11 around town.
I will NEVER own another Subaru.

[Mako Koiwai]

Darn AWD ... try pushing a Suby vs a FWD/RWD car and you can feel all of that extra linkage/differentials, etc.

Doesn't seem to hurt the BerryEvilMobil or Brian Peter's Porsche ... }:)

[Steve Ekstrand]

I had a friend that told me she'd never changed the oil on her new car. I went out and checked the mileage. It was 17K. I checked the oil. It barely hit the bottom of the dipstick. Two quarts down. I suspect that people that go big time miles hurt their motors more because of the levels dropping than because the oil went bad or was dirty.

BTW-I change my oil every 100 miles or so.

[Arthur Grant]

All the fluids in your car aren't that expensive. If your a wrench jocky (I am not) even less. Oil every 3K or 6 months. Works out to annual with the Vette, 12 months for Coolant, brake fluid and transmission. Differential is check and replace 30K unless otherwise specified or frontwheel drive.

I have a hard time understanding someone who can spend the time to set toe on a car in a parking lot, having trouble with an oil change. 5qts $20 bucks for synthetic at Wal Mart, $5 or so for a filter + time. or $25 bucks at lube haven.

[Mako Koiwai]

It's a PITA getting to the Legacy Outback oil filter. I change the oil myself in our other cars.

[Arthur Grant]

It's a PITA getting to the Legacy Outback oil filter

Thus why you pay someone. You shop at Wal Mart occasionally don't you?

[Will Kalman]

I have a hard time understanding someone who can spend the time to set toe on a car in a parking lot, having trouble with an oil change. 5qts $20 bucks for synthetic at Wal Mart, $5 or so for a filter + time. or $25 bucks at lube haven.

It's not the cost that's at issue, it's the necessity. Changing your oil every five miles isn't going to extend the life of your motor a bit or an interval of 100 or 1000 or 3000. So where is the line? It's easy to determine, you send samples to a lab and find out. Everything else is guessing and religion.

Unless oil has had a significant viscosity change, it works pretty darn good at lubricating no matter it's age unless you have a motor design that's truly an edge case with extremely tight tolerances (i.e. high-end race cars). It's the corrosion inhibitors, detergents, and other additives that "wear out". And back on thread, I doubt that will help Mako's motor stay alive or there would be hundreds of Subie's lining the roads and clogging up repair shops. I call bull on the mechanics suggestion of 3,000 miles changes unless that's what the Subaru engineers dictate. Nobody should ever have to do any more than the book says to keep their car in running order and receive the designed-for lifespan.

As an aside, I've never looked at the inside of a boxer motor - what keeps *all* the oil from pooling up behind the pistons during cornering? And, geez, wouldn't that create a *huge* oil consumption problem and efficiency decrease? I'd think some sort of windage/blocking plate but that would have to have holes to keep oil from building up behind it which would defeat the purpose during hard and sustained cornering.

[Steve Towers]

As an aside, I've never looked at the inside of a boxer motor - what keeps *all* the oil from pooling up behind the pistons during cornering? And, geez, wouldn't that create a *huge* oil consumption problem and efficiency decrease? I'd think some sort of windage/blocking plate but that would have to have holes to keep oil from building up behind it which would defeat the purpose during hard and sustained cornering.

Don't know what a "boxer motor" is but on C5's (no oil pan) there is a series of baffles on the (flat) bottom that are supposed to keep the oil from shifting to a bad place. That's the reason it's suggested to let the oil drain for at least 10 minutes when changing.

[Jayson Woodruff]

on C5's (no oil pan) there is a series of baffles on the (flat) bottom that are supposed to keep the oil from shifting to a bad place. That's the reason it's suggested to let the oil drain for at least 10 minutes when changing.

I've always wondered, does the baffeling trap debis in the pan, ready to flow into the new oil? If so, flush it a little?

Mako, sell it.

Jay W

[Will Kalman]

Don't know what a "boxer motor" is

Boxer = flat configuration, opposed cylinders. In a "normal" engine, the cylinders are above the crank case and the oil goes down into the sump by gravity. I wonder on a boxer engine if all the oil pours and pools up against the undersides of the pistons on one side when cornering.

http://en.wikipedia.org/wiki/Flat_engine" onclick="window.open(this.href);return false;

[Robert Puertas]

I've always wondered, does the baffeling trap debis in the pan, ready to flow into the new oil? If so, flush it a little?

They must be very small Debis to be there in the first place...

debx-inset-community.jpg (28.48 KiB) Viewed 9560 times

(Sorry, I really needed to change my post count)

[Bob Pl]

I had a friend that told me she'd never changed the oil on her new car. I went out and checked the mileage. It was 17K. I checked the oil. It barely hit the bottom of the dipstick. Two quarts down. I suspect that people that go big time miles hurt their motors more because of the levels dropping than because the oil went bad or was dirty.

BTW-I change my oil every 100 miles or so.

There are a lot of people out there like that, car is an appliance like a TV. Don't touch anything unless some idiot light or driver info center tells them to. Even those often get ignored. A friend who is the service manager at a large Toyota dealership told me 50% of the REPAIRS his shop does are caused by simple lack of maintenance.

[Arthur Grant]

I have a hard time understanding someone who can spend the time to set toe on a car in a parking lot, having trouble with an oil change. 5qts $20 bucks for synthetic at Wal Mart, $5 or so for a filter + time. or $25 bucks at lube haven.

It's not the cost that's at issue, it's the necessity. Changing your oil every five miles isn't going to extend the life of your motor a bit or an interval of 100 or 1000 or 3000. So where is the line? It's easy to determine, you send samples to a lab and find out. Everything else is guessing and religion.

Unless oil has had a significant viscosity change, it works pretty darn good at lubricating no matter it's age unless you have a motor design that's truly an edge case with extremely tight tolerances (i.e. high-end race cars). It's the corrosion inhibitors, detergents, and other additives that "wear out". And back on thread, I doubt that will help Mako's motor stay alive or there would be hundreds of Subie's lining the roads and clogging up repair shops. I call bull on the mechanics suggestion of 3,000 miles changes unless that's what the Subaru engineers dictate. Nobody should ever have to do any more than the book says to keep their car in running order and receive the designed-for lifespan.

As an aside, I've never looked at the inside of a boxer motor - what keeps *all* the oil from pooling up behind the pistons during cornering? And, geez, wouldn't that create a *huge* oil consumption problem and efficiency decrease? I'd think some sort of windage/blocking plate but that would have to have holes to keep oil from building up behind it which would defeat the purpose during hard and sustained cornering.

Will what you say is all true, but the bottom line is the dealer that replaced the engine for the third time, said change the oil every 3K. It's under warranty for one year, but if you don't follow their recommendation you risk that your not covered and lets be honest, this car is a lemon, either by build or design. On the 3rd engine I am betting by design.

The real answer is dump it if you can, but until then you need to play by the rules.

[Doug Kott]

I like to change my oil every 3K miles, or whenever I get the crazy urge to have scalding 10W-30 run down my arm. }:) My car's use typically consists of 3-5-mile errands, freeway trips to autocrosses, and the autocrosses themselves, so the shorter trips may not give the engine a chance to fully cook out condensation, etc. I like the peace of mind that the shorter interval affords.