96 Legacy Outback oil use

[DAntoniuk]

I replaced the heads on my 136,000 2.5 Legacy Outback wagon and it runs great and did not consume any oil after the repair. The cylinder walls didn't have any scoring and had the original cross-hatch and looked new. Suddenly, it stared using a quart in 320 miles. The PCV system is functioning well. Any ideas on what I should look at? Also, I live in the Rio Grande Valley of Texas, where it is very hot and dry. I will be changing my oil to 20-50 which will eliminate most of the oil consumption, but would like to know if there is a problem beforehand. Also, can I remove the driveshaft to the rear to improve my gas mileage without any side effects on the diff or transfer case? I really don't need AWD in South Texas!

[rcoaster]

Also, can I remove the driveshaft to the rear to improve my gas mileage without any side effects on the diff or transfer case? I really don't need AWD in South Texas!

 

No you cannot remove the drive shaft. The AWD system always sends power to the rear wheels. Besides, if you really don't need AWD in South Texas, why did you get a Subaru in the first place? Get a front wheel drive car.

[hklaine]

If I am correct removing the rear driveshaft will drain the trans fulid.

 

-Heikki

[Setright]

That's a lot of oil, any signs of it burning? Or is it leaking out of the engine block?

 

AWD is not to be tampered with.

[TheBrian]

AWD costs you about 3mpg (from cars101.com). In the Legacy, that works out to you spending about $900 per year on gas, versus $800 for a 2WD. Living with it is cheaper than doing anything about it.

 

I've read about people welding shut the center differential to convert their AWD Subaru to 2WD. Try a search here or on NASIOC. You'd need to plug the hole in the rear of the tranny, and the wheel bearings must not be loaded without CV axle ends in them. Converting to FWD would add a little pep, too, as you could remove probably 150lbs of rotating mass.

[DAntoniuk]

Thanks for the polite response. Most have recommended I leave the AWD intact. My oil problem may have something to do with fuel mixing with the oil. I will pull the plugs and do a compression test.

AWD costs you about 3mpg (from cars101.com). In the Legacy, that works out to you spending about $900 per year on gas, versus $800 for a 2WD. Living with it is cheaper than doing anything about it.

 

I've read about people welding shut the center differential to convert their AWD Subaru to 2WD. Try a search here or on NASIOC. You'd need to plug the hole in the rear of the tranny, and the wheel bearings must not be loaded without CV axle ends in them. Converting to FWD would add a little pep, too, as you could remove probably 150lbs of rotating mass.

[SubaruFreak]

regarding conversion from AWD to 2WD: Subarus have a unique solution to do that : check the fuse box in your engine bay. Look for an empty place with a simbol 2WD or something simmilar. I will check with my mechanic regarding this issue and report tommorow.

[Andyjo]

I wouldn't put the fuse in there, as stated alot on these forums, i've asked the question too.

It turns out that if you drive for a while with that fuse in it'll burn out your solenoid. i believe that's what was said.

[DAntoniuk]

I called a Subaru Manufacturer's rep. on this and was told it would eventually fry out the differential. I'm not sure why they put the fuse holder there. They may have told me this to avoid liability. I towed the car with the front wheels off the ground and the driveshaft disconnected for 120 miles when I first got it. This didn't cause any problems and I did not know that fuse holder was there. What I wanted to do until recent advice to the contrary is simply disconnect the driveshaft at both u-joints, remove the carrier bearing and let the other pieces free-wheel. Most have advised me not to mess with this, so I decided not to.

This weekend I plan to run a quart of engine cleaner for 30 minutes at idle and then change the oil to 20W50 as the book recommends for hot climates. I'm hoping to loosen a stuck oil ring.