What kind of mpg's should a 1996 OBW 2.5 get?

[weldersd]

I replaced the HG's a while ago, recently replaced separator seals and main seal, when I put in the motor I stacked the pump, I got another trans from a pica-a-part, it's working fine, shifts fine, it was torque binding so I swapped trans-end sections, fixed, but i'm getting about 18 mpg's before it was getting about 23, what happened? I replaced the wires/plugs too.

[Fairtax4me]

Checked the timing belt?

It's also cold now, that can make a fair difference in MPGs. Tire pressures all to spec?

Any idea when/ if the front O2 sensor has been replaced?

Any Check engine light? Does the bulb work when key ON?

[bstone]

MPGs, not MPG's.

[WoodsWagon]

22 around town, 28 on the highway.

[Rooster2]

Can't remember if your 2.5 would have a PCV valve? If so, if it is bad, it can bring down gas millage.

 

It might help to add a can of injector cleaner to the gas tank. Put in the good stuff that costs about $6 a can. Recommend Chevron Techron. Clean injectors help gas millage too.

[weldersd]

MPGs, not MPG's.

Wow, very helpful thanks

 

Can't remember if your 2.5 would have a PCV valve? If so, if it is bad, it can bring down gas millage. I think it does, I will replace it.

 

It might help to add a can of injector cleaner to the gas tank. Put in the good stuff that costs about $6 a can. Recommend Chevron Techron. Clean injectors help gas millage too.

I use chevron every fill up, i'll try the cleaner

 

22 around town, 28 on the highway.

wow, I wish we were getting that.

 

Checked the timing belt?

It's also cold now, that can make a fair difference in MPGs. Tire pressures all to spec? yes, I run nitrogen

Any idea when/ if the front O2 sensor has been replaced? 3 years ago??

Any Check engine light? Does the bulb work when key ON?

no, yes.

[johnceggleston]

it sounds like this has been a fairly long process. if you started in the summer or fall, and now just got it back together in the winter, part of the problem may be ''winter gas'', it gets less mpg than summer gas.

 

how many tanks of gas have you driven since the swap?

 

was the engine an exact match?

 

is the trans final drive ratio an exact match? do the trans code numbers match?

 

it may not be any one thing , but it may be a combination of things.

[weldersd]

it sounds like this has been a fairly long process. if you started in the summer or fall, and now just got it back together in the winter, part of the problem may be ''winter gas'', it gets less mpg than summer gas.

 

how many tanks of gas have you driven since the swap?

 

was the engine an exact match?

 

is the trans final drive ratio an exact match? do the trans code numbers match?

 

it may not be any one thing , but it may be a combination of things.

 

I got a trans from a forrester of the same year, I understood the final drive was the same on the auto's, is this right? the speedo is right on. I did not swap engines, same engine, timing belt has approx 15000 miles on it, that's why I did not change it. The numbers were gone on my old trans so I could not make a match.

[wtdash]

I got a trans from a forrester of the same year, I understood the final drive was the same on the auto's, is this right? the speedo is right on. I did not swap engines, same engine, timing belt has approx 15000 miles on it, that's why I did not change it. The numbers were gone on my old trans so I could not make a match.

 

Hi,

Just to clarify, the only thing you changed since it was getting 23 mpg - is the trans, correct? (You only replaced the two seals.) It was getting 23 after the HG job?

 

And when you "swapped trans-end sections" you used the '96's?

 

Foresters didn't come out 'til '98, but according to 'opposedforces.com' (choose your model and it's listed under Train) both are 4.44, so that shouldn't be an issue.

 

Wondering if the final gear ratios (?) are a bit different (I've read the Outback 5-speed is different than the Forester's - maybe the 4EAT is, too)...although you stated the speedo is still correct. I looked in a '98 Forester Owner's Manual but didn't see the actual ratios...Subaru used to show that info in the older models' manuals.

 

And since you're in San Diego, do you have 'winter gas' down there, too?

 

Last (only?) idea...if you can get a TCU from the Forester, it may help. Maybe the TC isn't locking up properly?

 

GL,

Td

Edited December 29, 2011 by wtdash

[weldersd]

Hi,

Just to clarify, the only thing you changed since it was getting 23 mpg - is the trans, correct? (You only replaced the two seals.) It was getting 23 after the HG job?

 

And when you "swapped trans-end sections" you used the '96's?

 

Foresters didn't come out 'til '98, but according to 'opposedforces.com' (choose your model and it's listed under Train) both are 4.44, so that shouldn't be an issue.

 

Wondering if the final gear ratios (?) are a bit different (I've read the Outback 5-speed is different than the Forester's - maybe the 4EAT is, too)...although you stated the speedo is still correct. I looked in a '98 Forester Owner's Manual but didn't see the actual ratios...Subaru used to show that info in the older models' manuals.

 

And since you're in San Diego, do you have 'winter gas' down there, too?

 

Last (only?) idea...if you can get a TCU from the Forester, it may help. Maybe the TC isn't locking up properly?

 

GL,

Td

 

Your correct, I only replaced the seals behind the flex plate, the only difference is the trans. the guy at the yard said it was a 4.44 ratio. I didn't know foresters started in 98, hmmm. I also was suspecting the TC lock, but the RPM's at 60mph seem the same as before?? I wonder if I should get the TCU, where is it located? if I posted the number off the new trans would any of you be able to steer me to the correct TCU to buy?

[Suba9792]

Just to clarify.....the ej25d wasn't offered until 1997. So unless for some odd reason you swapped one in you have an ej22. With proper maintenance you should be getting at least 26 to 27. I have a 97 legacy with an ej22 and i get in the 30 mark, I'm also a bit lighter as well, than an OB. But I'm a maintenance freak so yeah.....good mileage.

[Suba9792]

Try replacing th

e up stream o2 sensor, as well as giving it a gob of seafoam. Failing,or failed o2 sensor will cause poor mileage.

[wtdash]

Just to clarify.....the ej25d wasn't offered until 1997. So unless for some odd reason you swapped one in you have an ej22. With proper maintenance you should be getting at least 26 to 27. I have a 97 legacy with an ej22 and i get in the 30 mark, I'm also a bit lighter as well, than an OB. But I'm a maintenance freak so yeah.....good mileage.

 

Sir,

No disrespect, but your info is incorrect.

 

The EJ25D was avl. in '96 on the Automatic transmission cars only OB/GT/LSi - it had the HLA-valve heads and made 155hp/140torque. In '97+ they went w/the shim/bucket adj. valve heads and made 165/162.

 

The '96 OB 5-speeds still had the EJ22e.

 

Wiki: http://en.wikipedia.org/wiki/Subaru_EJ_engine and

Cars101: http://www.cars101.com/subaru/outback/outback1996.html

 

Td

Edited December 30, 2011 by wtdash

[Suba9792]

Well that is too bad, the ej22 would have been nice mated to the 4eat in the OB. Huh always thought it didn't come out till 97

[weldersd]

Considering I have now pulled the motor four times, replaced just about everything on it, I would say I'm pretty familiar with the motor, and it is definitely a EJ25D, the vin code says it's a late year production version. to answer a question, the process was not long, I removed the motor, replaced seals, replaced motor/broke trans:-\ found new(used) trans, installed and replaced trans extension in four working days. this car is my wifes daily driver so it has to be in service.

[weldersd]

Sir,

No disrespect, but your info is incorrect.

 

The EJ25D was avl. in '96 on the Automatic transmission cars only OB/GT/LSi - it had the HLA-valve heads and made 155hp/140torque. In '97+ they went w/the shim/bucket adj. valve heads and made 165/162.

 

The '96 OB 5-speeds still had the EJ22e.

 

Wiki: http://en.wikipedia.org/wiki/Subaru_EJ_engine and

Cars101: http://www.cars101.com/subaru/outback/outback1996.html

 

Td

 

I love the fact that the valves are hydraulic self-adjusting, why would they veer from them in later versions?

[weldersd]

Try replacing th

e up stream o2 sensor, as well as giving it a gob of seafoam. Failing,or failed o2 sensor will cause poor mileage.[/quote

 

 

would a failing forward O2 sensor produce a trouble code? I definitely smell unburned fuel at idle

[wtdash]

Edit:

O2 sensor's do fail on these. The front one is the main one to worry about. The O2 is only used in 'closed-loop' after the car is warmed-up and @ light-medium throttle.

 

The CTS/temp sensor can also cause poor performance/MPG/etc.

 

I'd also check for a bad/leaking fuel injector now that you mention the fuel smell. It would also explain the MPG drop, i believe.

 

-Resistance test on the injectors should be ~12 ohms, IIRC.

-One of the smart guys can tell you how to check/test for a leaking injector.

 

TD

Edited December 30, 2011 by wtdash

[weldersd]

Hmmm, I'm thinking either bad/leaking fuel injector now that you mention the fuel smell. It would also explain the MPG drop, i believe.

 

-Resistance test on the injectors should be ~12 ohms, IIRC.

-One of the smart guys can tell you how to check/test for a leaking injector.

 

TD

 

It barely passed smog a few months ago, I forget what it was high on, not nox, hc's? how do I resistance test injector modules? I guess I can refer to SM but you guys explain it better.

[wtdash]

It barely passed smog a few months ago, I forget what it was high on, not nox, hc's? how do I resistance test injector modules? I guess I can refer to SM but you guys explain it better.

 

Pull the clip off the injector (squeeze it and carefully wiggle and pull), and there are two pins to test across.

 

See above for my 'edit'.

TD

[weldersd]

I'm thinking at this point, since I last changed the forward O2 about three years ago, I should probably replace it, especially after removing it, while working on other things, getting dirty, etc, I understand the element on the sensor needs to be relatively clean correct? A previous post said I should use sea foam, what does that do? I don't quite understand how after a trans swap now loosing 5mpgs (is this correct grammar PD?) some snake oil in a can will bring back my mpgs, but hey, i'm no expert. The decline in mpg's from the original rebuild has been progressive, I think it's just time to do the O2 sensor, this is why I hate gas engine, a subaru is the only gas engine I will tolerate, the rest of my vehicles are diesel. I wish subaru would offer a diesel version, that would be the most bad rump roast car ever. and not a over restricted techowiz POS, I mean a simple mechanical, turbocharged, diesel, a guy could dream, right?

[johnceggleston]

I love the fact that the valves are hydraulic self-adjusting, why would they veer from them in later versions?

 

apparently the shim and bucket lend themselves to more horsepower. and the HLAs in the 96 ej25 is not the same set up as the 96 ej22, the DOHC doesn't have conventional rockers, it's cam to valve with an adjuster in between.

 

when they went back to SOHC they went with conventional roller / rocker set up. right?

Edited December 30, 2011 by johnceggleston

[weldersd]

can anybody give me a rpm@ 65 mph? i'm showing about 2600

[weldersd]

apparently the shim and bucket lend themselves to more horsepower. and the HLAs in the 96 ej25 is not the same set up as the 96 ej22, the DOHC doesn't have conventional rockers, it's cam to valve with an adjuster in between.

 

when they went back to SOHC they went with conventional roller / rocker set up. right?

 

 

If you think about it, it does make more sense, the conventional rocker configuration does seem more of a structurally sound design than the bucket/shim config. that's why you don't see many (any?) diesels with HLA design, it's kind of like open vs closed deck engine configurations. edit:I wonder if one of the reasons the HLA designs require a higher octane fuel rating is the consequences of a premature detonation is much greater than a pure mechanical set-up?

Edited January 1, 2012 by weldersd

[weldersd]

update: I replaced the upstream o2 sensor, knock sensor, and I removed the cat's I plugged one end of the pipe and poured detergent in the pipe, let it sit for a while, then rinsed, the cats seem free flowing and clean, I cleaned the pcv valve, it seems to be working just fine (blow test) all vacuum lines are attached and look ok. Mileage got a little better, but still around 20 ish city, when before the trans swap I was getting 23 city. here is the number off the new (used) transmission: TZ102Z2AAA-CG another sticker below that number showing: 933685, can anybody tell me EXACTLY what trans this is and if I need another TCU?