2000 Legacy Outback help... mabe tranny?

[TheGr8Doughboy]

First post, I searched a little and read some horror stories with the trannys... hopefully this is not the case. I'm a decent wrench but I'm used to older Toyotas... and this fuel injection and ECU stuff is new territory

 

My girlfriend lets me have her car today since mines out of commission (F*rd) but all of a sudden it's running really poorly! I must fix this before she gets back in town Monday or she WILL KILL ME.

 

Car: 2000 Subaru Legacy Outback. She bought it at 50K it's at 73K this is her frist trouble with it

 

Symptoms:

• Getting a bad O2 sensor from OBDII scan... but no check engine light
  
• Lopes a little at idle (attributing that to bad O2 sensor)
  
• When starting from a stop it boggs down 'till you give it more gas then takes off
  
• It "bucks" while cruising at any speed above 25 mph... give it more gas and it bogs down for a second then drives fine.
  
• If I rev it up in the parking lot... it's fine
  
• The tach doesn't jump around but at a stop light it was surging/stumbling and the tach didn't register that either
  
• Turned into a gas station and pressed the gas... nothing. Put it in nuetral and reved it up then put it in drive and it limped up the grade.
  
• Fluid smells like... well tranny fluid. It's not red... kind of a brown hue and frothy (car was running, I think that's right isn't it?) and had enough fluid.
  

 

Guesses

• Tranny issue and the torque converter is going in and out of lock up
  
• Fuel pressure regulator? But not really cuase it idles ok...
  
• No way the 02 sensor could cause this... I was worried I wouldn't make it back to the house... right?
  

 

 

Help please. I know the 02 Sensor needs to be replaced but we're on a real tight budget so that may have to wait till the tranny gets sorted out. (<- read poor college students)

 

Thanks

Chris

[OB99W]

[...]Fluid smells like... well tranny fluid. It's not red... kind of a brown hue and frothy (car was running, I think that's right isn't it?) and had enough fluid.[...]

To start with, as you might expect, "brown" ATF isn't a good sign. However, "frothy" has me more concerned. If we're talking air bubbles, the trans really isn't going to like that. Proper operation is dependent to a great degree on the inability of ATF to be compressed much, and air of course can be. So pressure isn't applied correctly when ATF is aerated. It also doesn't convey heat as well when airy. Etc.

 

There's "enough fluid"; are you sure? Too much can be as bad as too little. If you're not exactly sure how to check the level, see this:

http://www.endwrench.com/pdf/drivetrain/02Winter4EATDiagServ.pdf

 

If the froth is more than just air, that's another concern. There may be a small leak in the transmission cooler, which is inside the radiator. That can lead to coolant getting into the ATF, with drastic results. If there is any milky tan or pink emulsion on the trans dipstick, or in the radiator reserve ("overflow") tank, it could indicate a trans cooler leak.

 

If you can be a bit more descriptive of the "froth", etc., it might help with the diagnosis. A complete fluid change is probably in order, but there's not much sense in doing that if there are other issues that need to be seen to first.

 

By the way, are you saying that with all that was going on, the tach never seemed to indicate revs over or under what would be "normal"?

[TheGr8Doughboy]

Even though this isn't my car I have driven it quite a bit and we have had no warning signs of anything being wrong. The tach behaved exactly as expected when shifting or accelerating. However when it was bucking and surging it would maintian a constant RPM (I noticed 2K in particular during one spell).

 

Bubbles. She has the camera with her out of town so I cannot post a picture. The fluid was definately a dark red with brown hue. The bubbles were in small groups (3-4) and there were 3-4 groups of them on there. They looked like air bubbles, like you'd findin hand blown glass, rather than contaminant (but this is my first auto trouble shooting).

 

Thanks for the link. I neglected to select all of the gears before checking the fluid level. I will go do that now.

 

Thanks so much, I searched before posting and couldn't find anything that matched these symptoms.

 

Chris

[TheGr8Doughboy]

Ok. Allowed the car to warm up, selected all of the gears then checked the fluid. It's on the low side of the cold marks. No leaking underneath. It's a little wet around the pan gasket but nothing I would consider a full on leak.

 

There's no discoloration in the overflow tank in the radiator everything's fine there (she does a good job of checking her oil and coolant and sindsheild washer fluid ) I will try and catch some of the tranny fluid in a cup for examination.

 

Ok, here's the plan. I'm going to order the 02 sensor. Then to a fuild filter change on the tranny. However I can't do any work in her parking lot... can I move it a couple of miles to my apartment without risking more damage?

 

Thanks so much

 

Chris

[OB99W]

Even though this isn't my car I have driven it quite a bit and we have had no warning signs of anything being wrong. The tach behaved exactly as expected when shifting or accelerating. However when it was bucking and surging it would maintian a constant RPM (I noticed 2K in particular during one spell).

The constant 2K tach reading accompanied by the engine misbehaving leads me to believe that you're experiencing an intermittent sensor problem, possibly due to a bad electrical connection.

 

Bubbles. She has the camera with her out of town so I cannot post a picture. The fluid was definately a dark red with brown hue. The bubbles were in small groups (3-4) and there were 3-4 groups of them on there. They looked like air bubbles, like you'd findin hand blown glass, rather than contaminant (but this is my first auto trouble shooting).

While the ATF condition you're describing doesn't sound great, it doesn't seem as bad as your initial description. It should probably be changed eventually, but may not relate to the current problem.

 

Ok. Allowed the car to warm up, selected all of the gears then checked the fluid. It's on the low side of the cold marks. No leaking underneath. It's a little wet around the pan gasket but nothing I would consider a full on leak. I will double check that there's no leaking at the cooler.

I'm assuming that you're not driving the OB, so the "warm up" was just from idling. It takes about 20-30 minutes of idling to get the trans near operating temp if it's cold, so the fluid may not have expanded enough to get an accurate level reading. However, assuming that you're parked on level ground, a reading after warmup from even just idling that's "on the low side of the cold marks" would seem to be somewhat low. You might try adding no more than 1/2 pint of ATF (Dexron III type), and recheck the level after a 10 minute drive. Add more if needed, but don't overfill.

 

Ok, here's the plan. I'm going to order the 02 sensor. Then to a fuild filter change on the tranny. However I can't do any work in her parking lot... can I move it a couple of miles to my apartment without risking more damage?

The bad O2 sensor may or may not be contributing to the problem; it certainly can affect fuel/air mixture and emissions. In my opinion, what the tach is indicating is more likely to be related to other things, perhaps speed sensors. Speed sensor data is used by both the engine and transmission, and neither will run correctly if that data is untrustworthy.

 

By the way, although the trans holds about 10 quarts in total, draining via the plug on the pan will only allow about 4 quarts to be changed. If you want to replace all of the ATF, it may be best to have a shop do a "flush". That will usually run about $100.

 

Without knowing exactly what's wrong, I really don't want to advise you on the safety of moving the OB. Sorry. Perhaps someone else can offer some further advice.

[brus brother]

If you are suffering from "mafundsarelow" try multiple drains and fills of AT fluid (Dextron I think? check manual). Cheap enough at WalMart by the gallon. Even if it's not a complete drain and refill the first time through, after you've drained, filled, spun around the block a few times and repeat drain, refill, spin around the block, repeat, you get a pretty good result under the circumstances. It's mentioned a few times on the board. Just don't overfill. If you are sure that your initial level is good, drain say 5 quarts and add 5 quarts... simple math at the college level. Good luck.

[TheGr8Doughboy]

Wouldn't a bad speed sensor give a code? Will I be able to read tranny codes with the OBDII scanner? What tells these converters to lock up? It should be a combination of the speed sensor and a throttle position sensor right? What else can I do to trouble shoot it? What can I rule out at this point?

 

A friend of mine stopped by for lunch and we were pondering it and he looked at the oil on the dipstick and noted that it almost looked like clean motor oil, but it definately smelled like ATF. (I'm pulling the dipstick on the drivers side up by the firewall) It's hard to tell the color by the thin film on the dipstick...

 

Bus Brother, good call on that. Sounds more in my budget than a $100 tranny flush.

 

Gettin a little worried

Chris

[TheGr8Doughboy]

Ok. Ruled out the tranny. Went and got the codes read again and got PO301-PO302-PO303-PO304 engine misfire on all cylinders....

 

Now what? There's a little motor oil on the boots of the plug wires where they enter the head. Strange? maybe not. Coil? Haven't pulled the plugs yet (getting there) but this could explain the 02 code right? With the unburned fuel?

 

Thanks

Chris

[brus brother]

Oil on the boots is another issue. There are grommets where the plugs go thru the valve cover . They need to be replaced occasionally, mine were done on my 2000 Legacy GT around 40,000 under warranty. It's a known issue. I think you pull the valve covers and replace the valve cover gasket at the same time as these grommets. Put this on the bottom of the honey-do list until you sort out the power issue.

[Scottbaru]

Look for a vacuum leak, that could cause several of the problems you're having. Probably not a head gasket, but look in the coolant for bubbles/oil. At that mileage a bad O2 sensor is unlikely. Cleaning the plugs, plugwires, and plugwells should temporarily fix any symptoms from oil on the plugs. You asked somewhere about an OBDII scanner, I'm using a Proscan http://myscantool.com/, some screenshots are here http://forum.ih8mud.com/showthread.php?t=75975&page=3. Now, what's wrong with the cruiser?

[OB99W]

[...]A friend of mine stopped by for lunch and we were pondering it and he looked at the oil on the dipstick and noted that it almost looked like clean motor oil, but it definately smelled like ATF. (I'm pulling the dipstick on the drivers side up by the firewall) It's hard to tell the color by the thin film on the dipstick...[...]

I assume that you're wiping the dipstick before reinserting to take a reading (if not, it's difficult to get an accurate reading). If so, use a clean, white, lint-free cloth, paper towel, or napkin. You can then get a much better idea of the color of the ATF.

 

Ok. Ruled out the tranny. Went and got the codes read again and got PO301-PO302-PO303-PO304 engine misfire on all cylinders....[...]

That's a different situation. The trans can certainly seem to be problematic when the engine is misbehaving that badly. Misfire can have several causes. Remember that besides spark, air and fuel have to be there in the right amount and at the right time. Can you tell if the misfire seems to be lean or rich? Something as simple as a bad batch of gas, especially if it partially plugs the fuel filter, could be the culprit. Or, possibly something getting sucked into the air intake. Even exhaust system problems can cause misfire.

 

If ignition cables are bad enough, leakage (especially if they get wet) can certainly cause misfire. You can sometimes see the problem if you look under the hood with the OB in a darkened area, especially at night.

 

Since the problem came on suddenly, I'd suggest thinking back to anything that happened very recently, like a gas tank refill immediately preceding it.

 

If something obvious doesn't show up, I'm still wondering if this could be sensor-related. Best of luck.

[friendly_jacek]

Doughboy,

Fix the F/A ratio (aka O2) sensor first. It is a weak point in 2000 subaru. There was a recall for it in 2001. They can fail without triggering the light and cause alarming drivibility issues. Search here and you will find several examples fixed by new sensor. BTW, there are surprisingly inexpensive in Subaru dealerships, 60-80$ (internet vs brick).

As for the tranny, maybe the new fluid will fix it. Hopefully, as this is another soft spot in 1999-2000 subarus.

[TheGr8Doughboy]

Thanks for the help. I did check for intake leaks with carb cleaner. And the cruiser is getting SOA and 700r4 with NP203 as a doubler.

 

There was no oil on the plugs just on the plug wire boot... just thought the oil was kinda strange. Anyway, the old plugs were gapped a little big .050 or so but otherwise really clea.

 

Here's an update: New plugs and fuel filter (plug wires are not in stock, will call dealership in a second)

 

Started up fine, stumbled a couple of times at idle I assumed as the fuel fliter filled up.

 

So I took it for a test drive. Fine as first and I called my brother (he's a Subie owner as well) to celebrate. As soon as he picked up it stalled out at a stop sign. Then started right back up and kept going, slight uphill it started bogging down, this time instead of bucking and carrying on it started missing and backfiring. And when it was missing and carrying on as soon as I kicked it into neutral it ran fine then fine for a second back in drive before it repeated. Still no check engine light... I did only drive it for about 10 mins.

 

Is 02 sensor bank 1 sensor 1 the one in the cat?

 

Does this thing have an EGR valve? I haven't found anything yet...

Thanks for all of the help so far.

 

Chris

[TheGr8Doughboy]

OK, I unhooked the 02 sensor that's in the cat (I don't know if this is sensor 1 or sensor 2) but it ran ok at first untill the car warmed up. So do I need both an 02 sensor and the engine temp sensor?

 

Secondly. After getting to know my Subie a little better I found that the FWD fuse slot is empty. Does this mean my OBW is in front wheel drive? or that I need to insert a fuse to put it in FWD?

 

Chris

[Gnuman]

Secondly, after getting to know my Subie a little better I found that the FWD fuse slot is empty. Does this mean my OBW is in front wheel drive? or that I need to insert a fuse to put it in FWD?

 

Chris

 

The latter. the fuse is used to lock out the rear drive output. When you insert a fuse, there should be a FWD indicator that will light up on your dashboard

[friendly_jacek]

the sensor that affects A/F ratio is the bank1/sensor1 and is located near where the 2 exhaust pipes from engine merge. The bank1/sensor2 just monitors the cat efficiency and is screwed in the the rear of the cat.

Disconnect the sensor 1 and see if it changes anything.

[OB99W]

OK, I unhooked the 02 sensor that's in the cat (I don't know if this is sensor 1 or sensor 2) but it ran ok at first untill the car warmed up.

The ECU runs "open loop" until the engine is warm. That is, it ignores things like the O2 sensor data (no voltage when cold) and uses a rich-running default. Since your engine runs okay until warm, it's a clue that the ECU is probably getting bad sensor data after warm-up, and misadjusting the mixture.

 

OBD-II monitors how well the cat works; sensor 1 is before the cat, sensor 2 is after, and comparing the readings allows determination of cat efficiency.

 

With all the trouble codes you've been able to retrieve, I'm surprised that none of them have caused the CEL to light. Does it come on as it should when the engine is first being started?

[TheGr8Doughboy]

I think the 02 code may have been an old code. The car owner admitted that she'd seen the engine light come on for about 10 mins as she was merging onto the interstate so I think the 02 code may have been from that. Since that light came on we have driven the car probably about 500 miles and 2 weeks.

 

There was a check engine light that came on when I got the misfire readings.

 

If I unplug the first 02 sensor will this cause the ECU to continue to run "closed loop"? Is there a way to set the ECU to closed loop so I can drive this to the dealership if the 02 sensor does not fix this tomarrow to let them run a diagnostic for it ($80).

 

Thanks again for the continued help.

 

Chris

[BLZ2DWL]

Doughboy, looks like I told you wrong (thats what you get for taking advice from a guy with a fwd scooby). You put a fuse IN to disable the AWD, not take the fuse out. If you have no fuse, you're good to go. Now, you could put one in to disable the AWD and see if you're having a tranny problem. Otherwise, I think you've got a good gameplan with the O2 sensor. Good luck. Let me know if you need any other mis-information (I got lots of it).

 

 

Brennan

[friendly_jacek]

I think the 02 code may have been an old code. The car owner admitted that she'd seen the engine light come on for about 10 mins as she was merging onto the interstate so I think the 02 code may have been from that. Since that light came on we have driven the car probably about 500 miles and 2 weeks.

 

There was a check engine light that came on when I got the misfire readings.

 

If I unplug the first 02 sensor will this cause the ECU to continue to run "closed loop"? Is there a way to set the ECU to closed loop so I can drive this to the dealership if the 02 sensor does not fix this tomarrow to let them run a diagnostic for it ($80).

 

Thanks again for the continued help.

 

Chris

So there WAS a code for the sensor!

Just replace it.

The ECU cannot run the engine in closed loop without the sensor. The sensor provides the "closure" of the feedback loop. It will run in open loop.

 

Edit: As I mentioned before, there was a recall in 2001 for the O2 sensor. If this was not done by your GF, dealership should do it free.

[TheGr8Doughboy]

The dealership said yesterday that there were no recalls for her vin number?

 

I'm headed there as soon as they open to grab one.

 

Chris

[OB99W]

[...]If I unplug the first 02 sensor will this cause the ECU to continue to run "closed loop"? Is there a way to set the ECU to closed loop so I can drive this to the dealership if the 02 sensor does not fix this tomarrow to let them run a diagnostic for it ($80).[...]

From your reports, the engine runs acceptably when cold, which is when the ECU is in "open loop" mode. You've said the rough running begins after warmup, which is when the ECU should already be in "closed loop".

 

Disconnecting the O2 sensor normally forces the ECU into "open loop" operation. You could try unplugging the O2 sensor, and see if the engine performance when warm is better that way. If so, the O2 sensor might be bad, but running okay with the O2 sensor disconnected doesn't prove it's the culprit, because when the ECU runs in "open loop" it can mask other problems.

 

By the way, for those of you with some test gear, it's not difficult to check O2 sensors. An oscilloscope makes it easy, but even a voltmeter with a reasonable input impedance is often sufficient.

[TheGr8Doughboy]

Replaced the 02 sensor. That was it. Runs fine now... I didn't expect it would be that easy!

 

Thanks so much for the help. I'll be around looking to get this car running ton notch.

 

Thanks

Chris

[friendly_jacek]

Glad to help, don't forget to change ATF.