[Norseman36]

Hey, I just bought a 2005 Subaru Outback 2.5 xt Limited with about 100,000 miles on it. I didn't notice anything wrong with it at first, but now I notice it idles rough most of the time. It has some vibration while I'm on the brakes right before I come to a stop. It also has been averaging 17 mpg in the city. I know it's unrealistic to expect the "official" mileage, but that seems low. I have been using 91-rated fuel in it since I got it, but I don't know that the dealership or previous owner used it.

It also has a very slow leak that burns off after leaving it for a few days and driving it. I took it to a guy who supposedly specializes in Subarus today and he told me it wasn't a head gasket or anything serious, but couldn't pinpoint what it was that was leaking. I don't know if that's related at all.

Thanks in advance for any ideas on what it could be!

 

[Norseman36]

Edit

 

[Peaty]

Aside from the typical things like air filters and spark plugs, my first guess would be the front oxygen sensor. Have you ever changed it?

When you say leak, are we talking motor oil?

 

[smn]

Do you have a code reader or something to take live data with? I use a bluetooth ELM327 device and an android app.

Many will suggest running some seafoam through the PCV valve, and/or change the pcv valve, etc... how does the intake air filter look?

 

[tdelker]

MPG is very hard to compare against since everyone drives these XTs differently.

Vibration description is hard to follow. Is it brake related?

Rough idle - Does it change whether it is in D or N?

Slow leak - Can't tell what kind of leak. How do you know it 'burns off'?

What is the maintenance history? Plugs ever changed? Do you know about the banjo bolt filter issue?

At 100k, you are close to timing belt (105k)

Tom

 

[Peaty]

Seafoam is a good idea but not through the PCV valve (especially on a turbo it's harder to get to than an NA) Using the PCV valve only feeds one maybe two cylinders. To do it properly and evenly hit all intake runners, do it through the throttle body. The new aerosol form with the funky dip tube. It makes it a lot easier.

 

[cardoc]

^ To add to that, you can use the vacuum port from the brake booster or fuel pressure regulator to feed it into the engine.

Being a turbo, anything related to the intake system can effect idle, performance and fuel economy. Check for any leaks in the air tube between the MAF and throttle body. Clean the throttle body. Yeah its a chore. Try to check the function of the front AF sensor, engine temperature, LTFT and MAP with a scan tool that reads data. If you can make a recording of the data and post it, it would help.

91 Octane at a major oil company station vs Murphy or a mom and pop has its differences in ability to burn proper.

It may just need a tune and yeah, get ready for a front engine overhaul: T-belt, pulleys, seals, thermostat and coolant flush. Water pump is a toss up.

 

[Peaty]

I'm telling you the only way to get all cylinders is to go through the throttle body, the brake booster feeds off of one intake runner on some scooby motors. Even subaru says to do it through the TB:

http://www.scoobymods.com/showthread.php/idle-speed-control-valve-cleaning-3909.html?t=3909

SEA FOAM SPRAY - 12 OZ. AEROSOL

"Sea Foam has introduced a convenient new long-reach straw for performing an engine treatment in special situations like Vortec engines and Subaru’s H style engines, where there is no single vacuum line for all cylinders. These situations require spraying of Sea Foam Spray directly into the throttle body."

go here:

Sea Foam | How to Use Sea Foam Spray | General Content - Sea Foam Spray

and click open all.

This might be worth looking at too:

http://www.scoobymods.com/showthread.php/high-mileage-recirc-valves-worth-12353.html

 

[Norseman36]

OK, thank you guys for all the responses first off. I need to clarify things!
I just bought it a week ago, so I'm not 100% sure what's been done to it. The Carfax report indicated that the CV Boots were replaced and the engine oil has been changed regularly, that's about it.

I believe the leak is oil, at least it smells like it. I am an amateur at diagnosing and repairing cars, however, and this is my first Subaru. If we let the car sit a couple days and drive it, something is burning off the engine and smoke/steam is coming out the hood scoop when it is stopped at a light. I get a burning rubber type smell along with the smoke/steam.

The vibration I feel when I decelerate feels like vibration in the engine, not on the brakes.

I don't know about any of the problems with these particular cars yet, however, I feel like I am about to get very familiar with them. I have not heard of the Banjo Bolt Filter issue, but I will look into it. It sounds like I am in for an overhaul. That's what I get for hastily buying a car, I suppose. I will take a look another look at the car tomorrow when it's light

Again, thanks for the responses and sorry for the grouchy comment earlier.

 

[rasterman]

17MPG is not considered "very low" for an XT. About right for mixed city/hwy in winter. You can see it go lower on a healthy car in all city driving, or up to maybe 27 if you hypermile through an entire tank at 60mph on cruise without stopping for a single light.

These cars were built to burn gas. That commitment is already made. It's all about how much fun you have burning it.

Don't fool around with the 105k maintenance interval, and get those leaks worked on. These engines don't tolerate deferred maintenance as well as the NA 2.5.

Welcome and enjoy your XT!

 

[serotta]

OK, thank you guys for all the responses first off. I need to clarify things!
I just bought it a week ago, so I'm not 100% sure what's been done to it. The Carfax report indicated that the CV Boots were replaced and the engine oil has been changed regularly, that's about it.

I believe the leak is oil, at least it smells like it. I am an amateur at diagnosing and repairing cars, however, and this is my first Subaru. If we let the car sit a couple days and drive it, something is burning off the engine and smoke/steam is coming out the hood scoop when it is stopped at a light. I get a burning rubber type smell along with the smoke/steam.

The vibration I feel when I decelerate feels like vibration in the engine, not on the brakes.

I don't know about any of the problems with these particular cars yet, however, I feel like I am about to get very familiar with them. I have not heard of the Banjo Bolt Filter issue, but I will look into it. It sounds like I am in for an overhaul. That's what I get for hastily buying a car, I suppose. I will take a look another look at the car tomorrow when it's light

Again, thanks for the responses and sorry for the grouchy comment earlier.

We just had similar symptoms (in bold above) with our 05XT. Turned out to be the valve cover gaskets seeping a bit. If you opened the hood after a good warm up drive, the smell was concentrated at the front driver's side of the engine. I had just replaced all the belts so I knew it shouldn't be them. The smell was not simply a burning oil smell, but a mixture of oil and burning rubber odor.

Wonder if the vibration at low engine speeds could be related to the CV boot replacement. If the axles were replaced along with the CV boot they could be causing the vibration. After market (non Subaru) axles have been known to cause similar issues.

 

[Peaty]

I have the TSB and some detailed photos about the filters to the AVCS system (Subaru's name for Variable Valve Timing)

http://www.scoobymods.com/showthread.php/tsb-02-97-05-rough-5782.html?t=5782

It's very easy to do and only takes a few minutes, worth a look.

If you can't see the photos on our site you need to register and log in. It's free, we do this to keep spam away.

There is an additional TSB about a screen in line to the turbo:

http://www.scoobymods.com/showthread.php/all-turbos-turbo-oil-line-8742.html?t=8742

That one is a bugger to get to.

 

[tdelker]

I believe the 05 AVCS union is very hard to get to (you have to shave a nipple off to get it out - walkthrough on LegacyGT.com). I wouldn't do it unless you are sure that's the issue.

The turbo one for 05 isn't easy, but it's not impossible either. Plenty of walkthroughs on legacygt as well. Same turbo in those cars.

3750 miles for oil change interval, only subaru oil filters, preferably synthetic (Rotella T6 5W40 is a favorite for value at Walmart). Replace the turbo banjo bolt filter immediately (next few weeks).

Start saving for the timing belt at 105k, or read up on how to do it yourself. It's not that bad if you skip the water pump, which is a toss up on whether to do it or not.

Take care of the oil leak.

Vibration is very possibly because of aftermarket axles. The common test is vibration in D at a stop, no vibration in Neutral. Subaru axles have green 'cups.' Plenty of pictures on here.

It's a blast to drive, you'll like the car, but there is some maintenance to take care of. Not that much more than a regular NA subaru, but some.

Tom

 

[Norseman36]

You guys are super helpful. I have class and work all day today, but have some free time tomorrow. I'm going to take it in and have the 105,000 maintenance done when my tax return gets in, which should be in a few weeks. I will just drive my Dodge Intrepid until then. I will also look at replacing the Banjo Bolt Filter in my limited free time.

Now that I mention the Intrepid. This "rough idle" feels like my Intrepid did after a spark plug went bad and one of the cylinders wasn't firing, I guess. Maybe it could be as simple as a spark plug? I don't see on the maintenance report that they had ever been changed. That would not explain the slow leak, though. WHY CAN'T THEY MAKE MAGIC CARS THAT NEVER HAVE PROBLEMS?

 

[tdelker]

If a cylinder wasn't firing, you would get a check engine light. You could go to an auto parts store that let's you borrow the code reader and see if there are any pending.

Hard to say for sure.

Spark plugs aren't part of the normal 105k. They are due at 60k and then again at 120k if properly maintained. With your car, who knows...

 

[cardoc]

Thinking on this more and your comment that it does it while slowing down: Check the transmission mount while your checking everything else.

 

[Norseman36]

Bringing this thread back from the dead. I've been out of town this week. I brought the car to a couple of mechanics. One of them looked the car over for a few hours and told me everything looked great on it except for a leaky power steering pump. He told me I needed to replace the air filter and spark plugs as well, but I did the filter myself and am tackling the plugs tomorrow. He said the pump wasn't bad, but that I should replace it if I didn't want to keep topping the fluid off.

I didn't drive the car at all yesterday after I drove 500+ miles this last week. This morning, I started it and it was shifting really hard and idling VERY rough, then, it started smoking out the hood scoop like it was doing before. After a while of running it, the rough idling stopped and it started shifting normally. I live in Idaho, so it is obviously cold. Should the temp affect the XT this much? Whatever was leaking eventually burned off. It's only when I let it sit for a day or so that it leaks enough to cause this smoking problem.

Also, I found this wet spot on the engine tonight while I was scoping stuff out for the spark plug job tomorrow. I have zero idea if this is near the power steering pump. I took this through a car wash today, but it was long enough ago that it shouldn't be wet.


I apologize if this is silly and exhaustive. I am new to these engines.

 

[cardoc]

That looks to be oil. The dipstick tube has an o-ring near the pull handle that seals the stick to the tube. Try changing the o-ring and clean the oil off again.

You could also be getting high crankcase pressure due to lack of ventilation and the pressure build up is finding an escape through the tube. Are you changing the oil regular? The PCV valve could be clogging or the boost pressures are getting past the PCV and into the crankcase.

 

[rasterman]

You can expect a lumpy shift or two when it is dead cold, but once warmed up you shouldn't notice anything. I would consider a drain & fill of the automatic transmission fluid. Insist on the Subaru HP fluid from the dealer. Weird stuff happens with the generic stuff from the corner auto part store.

I see it in XT threads all the time, and have observed it on my own car: Sloppy return-to-idle by the engine management. You're cruising along with barely a toe into the pedal, then you see a red light ahead and come off the gas to coast up to the stop and for half a moment there's a silence, then you're just barely aware of the engine starting to vibrate again, very slowly. Then it comes back up to normal idle and you feel that buzziness it does at idle in gear. I think it's just something XTs do. Not sure if it's good or bad, but quite a lot of them do it. This has never been made better nor worse by cold. Your car's idle shouldn't be bothered by cold until it's around -70°F, and other systems would have trouble before then.

I had a slight oil leak from mine, inherited from the previous owner. It turned out to be an o-ring between the oil cooler and the block. It's somewhat common on XTs, and it's certainly close enough to the exhaust to be your puff of smoke. Have a look at the oil filter and see if it has a film/drips on it seemingly from above. Note: cooler & filter are under the power steering pump area, so one problem can look like the other.

The picture you show is the opposite side of the engine. Any odor? there are fuel lines in that area, and some Subaru fuel lines have shown a tendency to shrink and leak in cold weather.

 

[Norseman36]

That looks to be oil. The dipstick tube has an o-ring near the pull handle that seals the stick to the tube. Try changing the o-ring and clean the oil off again.

You could also be getting high crankcase pressure due to lack of ventilation and the pressure build up is finding an escape through the tube. Are you changing the oil regular? The PCV valve could be clogging or the boost pressures are getting past the PCV and into the crankcase.

I just got the oil changed for the first time since I got it 1,000 miles ago. I will look into the o-ring. Hopefully that's all that is. The smoke I see comes off of the passenger side of the car, so I think this is a separate issue.