05 Legacy Lack of power - Transmission?

[austin.heather]

Howdy,

I've got an interesting situation which has many different aspects going on. Here is the problem...

When driving my 4speed auto transmission 05 Legacy, it seems to be lacking power. When I say that, I mean, the rpms will rev up to 4k or more before shifting to the next gear and I still feel like I'm driving grandmas car. It seems like the engine is doing an incredible amount of work for such little power transfer to the wheels. If it were a manual transmission, I would say the clutch is going out, but its an auto.

Some background info. Just did the whole timing belt job, new drive shaft assembly, new diff fluid front and rear, oil change, fresh coolant, new power steering pump. The car was recently purchased by someone who did not take good care of it and seems like im trying to catch up on lots of past due maintanance. It does read the classic P0240 code currently off and on.

Recently, checked the ATF and it was very low. It was driven for probobly at least a week in this condition (maybe longer, not sure). I added fluid to bring it back up to par, which helped it to shift smoother, but still doesn't seem to transfer power well at all. Literally, I feel like I'm gunning it off a stop sign and it moves like fat elephant.

Any ideas?? It is a california emissions special. which means 5 O2 sensors and 4 cats. could the P0240 code contribute to the lack of power?

[cardoc]

Was the transmission fluid dark or burned looking? If the transmission was run low on fluid prior for a long period, it would cause excessive wear on the clutch packs and seals. Torque converter damage can also occur with low fluid. Either of these conditions will cause what you are describing.

Does the engine idle, rev and seem to run normally other than the loss of power transfer to the wheels? If so, have the transmission checked.

The P0420 could be anything. See my post P0420 Diag .

[1 Lucky Texan]

might be worth triple checking the TB timing. They will run, but poorly, if they are off a tooth or 2.

but certainly the transmission is suspect given maintenance history and symptoms.

[austin.heather]

I had thought about timing. I simply assumed it would make more noise if It was off a tooth. When I stick my head under the hood and listen, it sounds like its running pretty smooth. Even sounds pretty good when I'm reving it as I go down the road. Just doesn't have the power. If anybody else thinks it could be timing, I will go back in there and double check.

The marks on the belt were off by half a tooth, so I did my best to keep the mark on the cam lined up with the body while keeping the belt mark as close as possible.

[1 Lucky Texan]

Originally Posted by austin.heather

I had thought about timing. I simply assumed it would make more noise if It was off a tooth. When I stick my head under the hood and listen, it sounds like its running pretty smooth. Even sounds pretty good when I'm reving it as I go down the road. Just doesn't have the power. If anybody else thinks it could be timing, I will go back in there and double check.

The marks on the belt were off by half a tooth, so I did my best to keep the mark on the cam lined up with the body while keeping the belt mark as close as possible.

yeah, that's typical I think - keep the hardware lined up. the belt marks are just 'guides' from what i've read.

[austin.heather]

Originally Posted by cardoc

Was the transmission fluid dark or burned looking? If the transmission was run low on fluid prior for a long period, it would cause excessive wear on the clutch packs and seals. Torque converter damage can also occur with low fluid. Either of these conditions will cause what you are describing.

Does the engine idle, rev and seem to run normally other than the loss of power transfer to the wheels? If so, have the transmission checked.

The P0420 could be anything. See my post P0420 Diag .

The tranny fluid did look dark when I first removed the radiator to do the timing belt. Almost black dripping out the bottom of the radiator. Is this transmission job something I can do my self? or is this a shop thing? I do not have any prior experience with auto transmissions, but if there is a step by step process to replace clutch packs and seals, I would like to give it a try.

The engine seems to idle fine, rev and run fine. which makes me believe its transmission related. There is some oil leaking from the head gasket, but I've driven previous subarus this was for a while without and dramatic affect on the power.

[plain OM]

If the engine responds to the accelerator and revs up "normally" under load, I sort of doubt engine power is the problem, but perhaps my understanding of this is not correct.

I note that the differential fluids were changed. I have the impression you know what you're doing, but I still feel I should confirm with you that it was the front differential that was drained and then refilled through the dipstick on the right of the car, not the dipstick on the left side.

There's no mention of replacing the ATF, other than topping it up. If it hasn't been done (especially given the color of the fluid that did come out), perhaps try three drain and refills of the transmission (see Changing Automatic Transmission Fluid (is easy)) with some driving or running the engine for a while between drains to circulate the fluid, and see if that helps at all. In this regard, and again just to confirm, the ATF should be checked with the car on a level surface, engine running, and after moving the selector through the gear positions.