Transmission, Engine, or All The Above?

[CityLights]

So, it's been a rough couple months lol. This car's messing with my head and I cannot pinpoint the issue. I drive a 2005 Subaru Outback LL Bean 3.0 EZ30 with a 5EAT Transmission. 167K On the ODO

This story starts off at the beginning of January. I was driving home about 40-50 MPH or so, was speeding up when suddenly my RPMs shot from around 3000 or so all the way up to Redline (7000) with no gain in power. I slowed down and went through my gears in the manual, it shifted fine and all my gears worked, though there was a loss of power. The "Sport" light began flashing indicative of a transmission issue, right? Also a CEL for "Output wheel speed sensor circuit fault", the transmission had the same code. Now I know now I jumped the gun here, but I thought with the slipping, car jerking when accelerating from a stop, and loss of power when climbing hills and speeding up, it had to be a bad transmission. Especially considering I took this car all up and down the east coast putting nearly 40,000 miles in a year. I bought a replacement 5EAT off a junked car and had it swapped it out over the course of a month. Big mistake having my school's auto shop do it. They didn't put any differential fluid in, and put in way too little transmission fluid. Once I noticed that and took it back, they overfilled it by 2 quarts. And I put the front diff oil in myself (about 1.5 quarts worth) There was also a leak in my exhaust flange temporarily underneath the transmission as it fell apart from rust when taken apart. After realizing about 2 weeks ago just how much transmission fluid was in there, I drained it, put a bottle of Trans X and refilled it to the proper level, ran it through its gears for a couple minutes and made sure the level with good.

So with the replacement transmission in, all these issues disappeared for a couple days. I drove it, it drove and shifted just fine, didn't slip or anything. It was seemingly back 100% with just a noisy exhaust leak. Then it started again. Started with the RPMs shooting up from 3000 to 5000 with no gain in speed or power, though with the exhaust leak I caught it before it got too high. I never let this new transmission go over 5000 RPMs. And now we get to present day. As the car is right now, it has a donut on the rear passenger as my wheel rim got bent, I'm searching for a new wheel now. The car runs and drives fine in speeds from 0-40mph, all the gears shift and engage. However once the engine warms up enough, there's stutter and hard kicks when accelerating from a stop. When up to speeds of 40mph and in any gear once the RPMs (especially going uphill) hit 3000, it feels like the transmission "lets go" and the rpms will suddenly climb with losses in power and speed, the transmission isnt downshifting, it also does it when I run it in manual. Once moving again, the car drives just fine as long as the speeds arent over 40MPH, otherwise the RPMs will skyrocket once they go over 3000RPMs. And the icing on the cake? I have a CEL now for "Fuel/Air Too Lean Bank 1" (though I'm suspicious it's my mass airflow sensor since the school managed to get that covered in Trans oil).

So I'm at a loss, did I burn a second transmission only days after getting it replaced? I was worried possibly the exhaust leak right under it was toasting and overheating it, but that was fixed shortly after.
All the wheel bearings were done recently, I do need new tires as the ones I have are worn way down. I heard possibly it could be my engine misfiring possibly. Or even my differential could be worn. Speed sensor possibly? If I can have any pointers to check out that would be great. I can't afford to take it to a shop right now as I'm dead broke right now and frankly sick of looking at it and putting more money into it. Thank you for reading this and any help would be appreciated.

[1 Lucky Texan]

one thing for certain, you must use the FWD fuse in the block under the hood if you mix tire sizes. Even very slight differences are very stressful on the drive train and it's usually the trans that suffers. so, use of the donut requires use of the FWD fuse.

seriously. tires need to be the same size/brand/model and near each other in wear.

that trans also needs OEM or compatible fluid. of course, check fluid level when idling.

[CityLights]

17 minutes ago, 1 Lucky Texan said:

one thing for certain, you must use the FWD fuse in the block under the hood if you mix tire sizes. Even very slight differences are very stressful on the drive train and it's usually the trans that suffers. so, use of the donut requires use of the FWD fuse.

seriously. tires need to be the same size/brand/model and near each other in wear.

that trans also needs OEM or compatible fluid. of course, check fluid level when idling.

I searched for the FWD fuse but on my car, apparently the 6Cyl And 5eat is special and it doesn’t exist at all. The fuse box under the hood has a label for the FWD fuse location but that block is entirely empty. No wired connections at all. I tried searching online too but apparently there is no fuse for my model, that is should “detect and disable the affected drivetrain”. 

[1 Lucky Texan]

ah, I guess that's right. I thought it was only VDC.

[idosubaru]

1. People often mistake engine and transmission issues. I see it all the time “will you look at my transmission, it’s slipping bad” ends up being an engine issue. The RPMs shooting up and lack of lower can emulate slipping but it’s actually not. It’s just so underpowered and poor performing everything is working against vehicle movement  

2. Was the original torque converter used or the one with the new trans?

3.  fix the engine issues first.  

4. list the exact engine codes your getting. Number and description. 

5. “Too lean” suggests there’s a simple vacuum leak, very common after an engine or trans pull.  Check the brake booster vacuum supply hose and intake hose and all fittings, clamps, etc. make sure there are no leaks.  

6. Spray starting fluid around the intake.  Start at the air filter and slowly work your past all the hoses, hose connections under the intake hose and to the engine where the intake clamps to the engine. With a bottle is starter fluid in hand this takes like 5 minutes or less. Easy.  

if there’s a hose leak it’ll suck the starting fluid in and just squirting fluid will cause the RPMs to jump.  Then you know you have a leak.  You should be able to spray that without any change to engine idling RPM.  Any change shows a leak. 

That’s a long explanation just in case you haven done it before, but it’s so easy, and that’s so common, give it a shot. 

[CityLights]

7 hours ago, idosubaru said:

1. People often mistake engine and transmission issues. I see it all the time “will you look at my transmission, it’s slipping bad” ends up being an engine issue. The RPMs shooting up and lack of lower can emulate slipping but it’s actually not. It’s just so underpowered and poor performing everything is working against vehicle movement  

2. Was the original torque converter used or the one with the new trans?

3.  fix the engine issues first.  

4. list the exact engine codes your getting. Number and description. 

5. “Too lean” suggests there’s a simple vacuum leak, very common after an engine or trans pull.  Check the brake booster vacuum supply hose and intake hose and all fittings, clamps, etc. make sure there are no leaks.  

6. Spray starting fluid around the intake.  Start at the air filter and slowly work your past all the hoses, hose connections under the intake hose and to the engine where the intake clamps to the engine. With a bottle is starter fluid in hand this takes like 5 minutes or less. Easy.  

if there’s a hose leak it’ll suck the starting fluid in and just squirting fluid will cause the RPMs to jump.  Then you know you have a leak.  You should be able to spray that without any change to engine idling RPM.  Any change shows a leak. 

That’s a long explanation just in case you haven done it before, but it’s so easy, and that’s so common, give it a shot. 

Here to answer your questions;

2; the torque converter was swapped over to the one in the new trans

4; the code I’m reading is P0171 system too lean bank 1

5; I did in fact find a vacuum leak on the throttle body using starter fluid! It nearly stalled my engine!! Thank you for this pointer will try to fix it as soon as the weather clears up!!

Also I took out the mass airflow sensor and there was quit a bit of junk on it, as I suspected trans oil did drip down into it and dirt and other small debris accumulated on it which is odd as my air filter is clean. Will replace it anyways.

[idosubaru]

28 minutes ago, CityLights said:

 

4; the code I’m reading is P0171 system too lean bank 1

5; I did in fact find a vacuum leak on the throttle body using starter fluid! It nearly stalled my engine!! Thank you for this pointer will try to fix it as soon as the weather clears up!!

Excellent - fix that and see if #4 goes away as I suspect it will and then see where you're at. 

ATF on the "MAF", as you call it, is odd but yeah clean it or replace with a used SUbaru unit. Aftermarket is *shoulder shrug* and OEM is such high quality and rarely fails that used is the way to go. 

[CityLights]

2 hours ago, idosubaru said:

Excellent - fix that and see if #4 goes away as I suspect it will and then see where you're at. 

ATF on the "MAF", as you call it, is odd but yeah clean it or replace with a used SUbaru unit. Aftermarket is *shoulder shrug* and OEM is such high quality and rarely fails that used is the way to go. 

I cleaned the sensor, like I said the school had gotten ATF all over my engine and there was a decent pool of it sitting on top of the sensor. Gave it a nice cleaning and will try and find out where the vacuum leak is specifically tomorrow. Can’t pinpoint if there’s something wrong with the throttle body or one of the hoses feeding into/off it

[CityLights]

So here’s where I’m at, I have my check engine codes all cleared out. It was indeed my brake booster supply hose that came disconnected. It’s loose and there wasn’t a clamp installed, I’ll get a $.50 clamp and secure it. Driving it now it’s still doing the same thing. However it doesn’t really feel like the transmission is slipping anymore. The engine has power back now that it’s not running lean. And once the speed hits 40mph it feels like the transmission is disengaging, going into neutral. I could be wrong but I have a hunch now that the mix of Old worn tires and the donut are causing my AWD system to possibly freak out and force a speed/power limiter. Because at low speeds and gears, the transmission catches and speeds up fine, doesn’t feel like it’s slipping at all. Even with the RPMS in the 5000 range, whereas when I’m in the 40mph range the trans let’s go at 3000rpm whether it’s in 4th or 5th gear.
 

So I intend on spending my next 2 paychecks on a new set of tires and rebalancing my wheels now that I can afford it. hopefully this resolves my problem, will keep you guys posted thank you for all your help so far!! I really appreciate it.

[idosubaru]

Great.

*** are these symptoms similar to before the trans swap or distinctly different?

1. if they’re different then maybe it’s something related to the swap work/new trans.

A.  Check fluid level.  I know you have but verify it’s right and not loosing fluid

B. Is the AT light flashing 16 times at start up?

C. Make sure the front CV axles are fully seated. They need seated all the way. 
 

if the symptoms are absolutely 100% Identicial we need to consider what non-trans item could be a culprit. 

[Rampage]

Because of the 40 mph symptom, I thought it might have something to do with torque converter lockup, but I found this in the FSM trans diag. section.

The CAN is communication between all modules on the car. The signals go through a lot of connectors.

I did not look, but the Factory Service Manuals always have a test procedure for the "Accelerator pedal position sensor" and the "Throttle position sensor".

[CityLights]

16 hours ago, idosubaru said:

Great.

*** are these symptoms similar to before the trans swap or distinctly different?

1. if they’re different then maybe it’s something related to the swap work/new trans.

A.  Check fluid level.  I know you have but verify it’s right and not loosing fluid

B. Is the AT light flashing 16 times at start up?

C. Make sure the front CV axles are fully seated. They need seated all the way. 
 

if the symptoms are absolutely 100% Identicial we need to consider what non-trans item could be a culprit. 

So here’a an update, I got all my tires done, donut is off the car, same symptoms prior to the tires.

A; the symptoms are indeed the same prior to the trans swap, but again, after the swap the symptoms disappeared entirely for a short while.

B; I don’t believe so. Would that be the sport light? All lights come on the dashboard but as all the systems check off they turn off one by one. All fluid levels are the same. I’m not losing any fluid All appears to be well in that regard. 

C; All axles are seated properly. Although, I did make an observation on my rear differential. The passenger side is covered in oil. Specifically where the axle inserts into the diff. This is the side where the donut was on the car, but also, a couple months back the shock went bad and the car was only supported by the spring on that corner. The car was bouncing all over the place cause of that. I drove it lightly for 2 weeks like that before the new ones came in and I replaced both rear. That was back in late october if memory serves me right. Could the rear differential be going bad? Would that possibly cause these issues? With the new and balanced wheels and tires I do still notice a slight shaking coming from I think the rear of the car.

 

 

 

Edited March 19, 2020 by CityLights

[CityLights]

15 hours ago, Rampage said:

Because of the 40 mph symptom, I thought it might have something to do with torque converter lockup, but I found this in the FSM trans diag. section.

The CAN is communication between all modules on the car. The signals go through a lot of connectors.

I did not look, but the Factory Service Manuals always have a test procedure for the "Accelerator pedal position sensor" and the "Throttle position sensor".

Thank you!! I will give these a shot this weekend!! I noticed my engine once warmed up appears to be idling lower than it used to. It used to idle around the 750rpm range but now the dash reads 500 and hooking a OBD reader onto the car reports the idle to be 650-690

[idosubaru]

let’s assume during the trans swap the battery was disconnect for awhile.  Disconnect it again for awhile to reset all the systems and see if the issues go away momentarily again.
 

replace the trans filter and cut it open to inspect for debris. 

I would verify all your transmission fluid lines are not damaged, stock, and not clogged. 

It couldn’t have been the tires. No surprise there  

i can’t imagine the rear diff causing issues without noise  and going away a bit after the trans swap

sounds like the rear diff is just leaking.  Not a big deal.  Pull the rear diff cover or plug and check for debris and swirls. Jack up the rear of the car and spin the rear tires - listen for noise/feel for binding. I highly doubt you’ll have any.  Subaru rear diff failure is so rare most people needlessly condemn them. 

[CityLights]

17 hours ago, idosubaru said:

let’s assume during the trans swap the battery was disconnect for awhile.  Disconnect it again for awhile to reset all the systems and see if the issues go away momentarily again.
 

replace the trans filter and cut it open to inspect for debris. 

I would verify all your transmission fluid lines are not damaged, stock, and not clogged. 

It couldn’t have been the tires. No surprise there  

i can’t imagine the rear diff causing issues without noise  and going away a bit after the trans swap

sounds like the rear diff is just leaking.  Not a big deal.  Pull the rear diff cover or plug and check for debris and swirls. Jack up the rear of the car and spin the rear tires - listen for noise/feel for binding. I highly doubt you’ll have any.  Subaru rear diff failure is so rare most people needlessly condemn them. 

So driving it around for a bit, the CEL came on and the Sport light began flashing again.

 

Theres an engine code; “P0700 Transmission Control System (MIL Request)”

And there’s an A/T code; “P0720 Output Speed Sensor Circuit”

Would it be possible my speed sensors are going bad? Or is this indicative of another issue.

[idosubaru]

If you’re getting a code then that circuit is compromised.  It doesn’t mean the sensor is bad - but rather the circuit which supports that sensor.  It could be, and often is, a sensor.  But in this case there’s additional stuff we know. 

Disclaimer - speed sensor issues are rare and I’m unfamiliar with specifics  

if the same thing has happened with two transmissions then speed sensors seem unlikely.  Because the speed sensor is in the trans so you essentially swapped speed sensor with no change in symptoms. Subaru speed sensor issues are extremely rare anyway. 

I would be inclined to suspect anything that is:

A: related to the speed sensor circuit

B: but not part of the transmission (because those sensors are in the trans and swapped with the trans). 

which means:

1. start following the FSM Procedures for that code with special attention to the wiring measurements - resistance, continuity, etc  

2. connectors And wiring - follow and inspect for damage.  Rodent damage or prior accident damage would be most likley. 

* any prior accidents?

* did it sit for an extended period or was it around urban chipmunks or farm field mice ?

3. the TCU itself. Not sure how to test those but I don’t think you can just plug and play swap that 2005 like you can a 2004.

[CityLights]

So here’s where I’m at today. I replaced the transmission filter with a genuine Subaru one. the fluid that came out of it didn’t look odd. No CEL, The wiring looks to be intact but the symptoms are still there.

 

Symptoms are stuttering when driving from a stop, I mean whole car shaking stuttering. Though if I have the transmission in manual mode and start in 1st the stuttering almost is never there...

 

Whenever I hit 40mph, doesn’t matter if I’m driving on a level surface, uphill, or downhill, it feels like the transmission puts itself into neutral. The RPMS will climb with 0 gain in power at all, and only re-engages when the car drops below 40MPH.

 

all fluids in the car are fine and to their proper level, no misfiring of the engine, it idles smooth. Though I did notice a deep, faint grinding sound when the car is both in park, and in neutral. When inside the car it’s best audible in front of the radio controls. It speeds up with engine RPM But it goes away when the car is in Reverse or Drive. 

[el_freddo]

Reading over this thread and with little auto experience, my question for you @CityLights: where did the replacement trans come from? 

I’m wondering if it’s from a crashed car or a parts car. 

And are speed sensors not like manual gearboxes where you can remove them from the side of the box and swap them around etc?

Cheers 

Bennie