The 4spd Auto is your first issue - the number one reason my first subaru back in 2001 was a MT 5spd. The filter - and dirty intake - and sensors can easily rob the engine of power.

Get the plugs NGK brand replaced - get the intake cleaned up - might want to check into replacing the fuel filter. Low quality and infrequent oil changes over many years can eventually rob an engine of its power ability. Try running a high quality synthetic oil for a couple of oil changes say 12,000 miles or so see if you start to see some improvement as the synthetic oil starts to strip away baked on oil deposits etc.

Though keep in mind the OB is heavy and the 4spd AT is a dog and that was the worst combo subaru had regarding snappy power and fun to drive car options. LOL

 

7


year


old


airfilter




gulp!

Well, not really knowing what you expect vs what you're experiencing, it's difficult for us to comment much. Is there a friend or coworker or perhaps a used car dealer that might have a similar vehicle to test drive?

If there is a CEL on, definitley get the codes (car parts suppliers will sometimes read these at no charge) report back here with the codes.

Do you know if any scheduled maintenace was done? If not, before doing much else (unless this is a project car, you want to diagnose before throwing parts and time and fluids and $$$$ at it) do a compression test, check for 'torque bind' (do a search here) and pull the covers to inspect the timing belt.

You may discover the TB belt is about to slip or break, the transmission has a problem in the wet clutch pack and the compression is low.

uh, we will want to know the mileage but, it may be as important to know if it only got short trips or highway miles.

 

Thanks guys for the input. Yea i wasn't too impressed when I saw the original filter either. I wish I could tell you more about the history of whats been done but the answer I get from all her family is.........not too sure, it just cost us $XXX and the paperwork is somewhere????
I never drove this car until a few weeks back. I do agree that the combination of power and weight wasn't the greatest design ever, but I can't believe anyone would ever put a car into production if this is how it would runs. I'm pretty sure that the lack of maintenance is the cause of a problem, just trying to pin point the general area to combat. I've wasted months and months on trying to find faults when they aren't obvious so I appreciate your advice and I've learnt from the past that throwing money at it wildly is a good way to empty the bank account and get nowhere.

The fuel filter is actually on order, so thanks for that. I'm thinking it's probably a bunch of issues, each all losing efficiency.

Here are a few thoughts which you guys may rule out for me.

I had a car come into a garage I used to rent time in. It showed similar problems but pretty much stopped one day. Had a coked up exhaust (it was the Catalytic convert to be exact) but it was quiet a big older than this car. Could a 2004 have this problem? I'm thinking no but its probably ran badly for a while.

Even though it sounds fine, one tooth out on the timing belt would show massive performance loss but might not appear to sound any different.

What do you think?

Will definitely replace all filters/plugs etc as someone should have had years ago anyway.

Millage is around 130,000 for a little more info.

Thanks again!

 

Timing belt is way over due and on borrowed time - if the air filter looks like a birds nest chances are the TB was never done. Do it or be prepared to junk the car when it breaks.

Thinking about the air filter vs oil changes at Jiffy lube those places tend to really jump all over the dirty airfilter given they mark it up and its easy money to replace so its a fair guess the car only saw one oil change for every three services it should have seen. LOL

So the lack of maint and many different things are probably adding up to a sizable loss in power.
Keep in mind that generation OB is not going to see much more than 25-27mpg tops on average and the bottom end is 19-23mpg so if your falling in that range your mileage is really not abnormal by any means.

 

I don't know what the problem with your car is, but just for comparison, I had a 97 outback, and now have an 09. The 97 was a manual, the 09 is an auto. The 4eat has a real dead spot, in my opinion, between second and third. It really needs another gear.

But I live in Colorado at 8000 feet and regularly drive mountain passes, 6 to 8 percent grades mostly, to 11 and 12 thousand feet. Usually the climbs are 4 to 7 miles, sometimes more. I can run up those as fast as I like to go, 50 to 60, if the road permits.

I used to usually run the 97 in third gear at around 3700 to 4500 rpm. I could have run it in fourth, but these engines do like to spin. I think it is better to shift down and hold a gear, than to let the auto pick its own.

With the auto, I can't run quite as fast unfortunately because it is just too big a jump between second and third. On steeper ground I end up putting it in seconattend going 50 or so. This is still acceptable to me. On flatter passes I can use third and go the speed limit. All of this is usually with two adults, maybe a dog, a couple of bikes and some gear.

The car is so great in the snow, and so reliable, that I'm OK with this level of performance. If you can make sure it has the right plugs, wires, filters etc. it should do better than what you are describing. What I notice, and it may be different where you live, is that a lot of Americans want to run their cars at 1500 rpm all the time, and a Subaru will always feel terrible if you don't wind it up a bit. Hope you figure it out.

 

Since we're all guessing, I'll guess that it's the air filter, or something adversely affecting your fuel/air mixture. So if the fuel filter is starving the engine at high rpms, or if the air-flow sensor is incorrectly reporting flow, these are the sorts of things that will cause a power loss at cruise... Also the front oxygen sensor or a MAP sensor can cause the same sort of trouble. Air filters cause some problems, but not usually problems as severe as you're describing. (At least not without fouling up the idle.)

 

Thanks for all your inputs! I'm thinking from what everyone is saying, that this car was no sports car in the first place. I'm going to replace the simple, basic service items and see what that gives me. If nothing chances, I haven'y lost anything as I'm betting they would need doing anyway. Will definitely take on board the Timing belt change, but I may first ring up my wife's family once more and see if she remembers ever having it changed. If you spend as much money as I think a timing belt will cost for this car, you must remember.....right?

Thanks again for all your help and I'll post back on this thread what I find when I've changed a few service parts.

Cheers guys. Johnny

 

It's no sports car, but you should be able to hold speed on hills. The problem you are having sounds very much like the issue I had with my old Legacy. It would be fine around town and at speeds less than 50mph or so, but once you tried highway hills, it would bog down. I could floor it and it would make no difference; the car would make almost no power. On this one particular hill that I drove frequently I would be at ~65 before the hill and no faster than 40 by the top. It would shake like crazy too. Smelled like rotten eggs.

The answer for my car was what JohnB said above about fuel starvation. There was a fuel leak from the rusted tank/fuel lines (*Keep in mind this was a 17 year old car, your car isn't rusted like this, don't worry) and caused problems when the engine was asking for a large amount of constant fuel.

There's so many things that could cause the problem you're having, but things I can think of off the top of my head are...

Air filter-check
Fuel filter
Check all hose clamps on the fuel lines in the engine bay and check for fuel leaks
Spark plugs (NGK or Subaru OEM only-others may work, but to be safe)
Spark plug wires (NGK or Subaru OEM only-others may work, but to be safe)
O2 sensor (especially front)
Clogged catalytic converter


Good luck.

 

If the fuel filter is under the hood it is easy to change, if it was a late build it may be integrated with the fuel pump and not really a serviceable part. Either way, I'd throw in a bottle of good fuel system cleaner in the car (I like Chevron Techron and Gumout w/ Regane myself).

Plugs (NGK), wires (NGK or Subaru), and PCV are all easy to do with the most basic tool set. The front diff, rear diff, and ATF (DexIII fluid, and Subaru AT filter if equipped) are also very easy to DIY. Although these may have been serviced at some point, very expensively.

If it has not had the TB done I would suggest the TB, all pulleys and tensioner, water pump as definate. Optional but suggest crank and cam seals, reseal oil pump, coolant service (Subaru coolant and conditioner if due).

 

I wouldn't forget the brakes. Fluid has probably absorbed a lot of water by now, caliper pins probably need greasing, etc.

If you could get the freezeframe data from the ECU, long term fuel trim might say a lot about MAF and O2 sensors. Regardless, that mileage is approaching the limit of front O2 sensors - again, IF it's never been changed. Make certain it has 50/50 coolant in the radiator. Hope it isn't mostly tap water!

Lift up the boots and feel for oil on top of the struts. Inspect axle boots. Most drivetrain stuff can probably wait though.

Double check that all the tires are the same size, model and wear.

 

I thought I'd better let you guys know what I did over the last couple of months as it sucks when people don't follow through with their findings. Usually time tells a tale.

All in all I haven't yet found any one cause to the lack of power and acceleration. I did change bits and bobs, like air filters, plugs etc. Fuel filter is in the tank so leaving that alone. I did change the timing belt, oil etc etc. It all together made a bit of a difference but the really interesting thing came when I drove to Salt Lake from Boulder. I set the cruise control to 70 mph which we never use and when I hit the first big hill, the car sprang into life and accelerated like never before. It never lost more than 2 mph the entire way up. This happened over and over again. When I turned off the cruise control and tried to accelerate up the hill with only the accelerator pedal, the car reverted to it charming slow and struggling self. It never tried to shift down a gear as quick and with as many revs as the cruise control when it did. It was like two different cars in one.

So the car can perform and does perform well......just not when you the human is accelerating.

I was thinking it may be the TPS but it wouldn't drive ok if that were the issue. So back to square one. At least I know the car can perform.

Please by all means chirp up...... I know its been a while since this thread started but I'm stumped once again!

Kind regards
johnny

 

Interesting update and distinction between cruise and manual speed control.

because your foot will be pushing the accelerator to the floor, and you will be luck if you are going over 35 mph,

Given that it's the same engine, tranny etc, I'm led to something that distinguishes the operation when in cruise. The first thing that comes to mind is the accelerator linkage. I believe that the 04 has the accelerator connected to the throttle through a cable (later models are "drive by wire"). If it's the cable type, then there's actually two cables going to the throttle mechanism on the engine -- one from the accelerator pedal, the other from the cruise control device. Is it possible that the pedal cable is mis-adjusted, thereby limiting the degree to which the pedal can advance the throttle plate? When requiring more throttle, the pedal might end up against the floor in manual control, whereas the cruise might have more range due to the properly adjusted cruise cable.

Similarly, are there any carpets etc on the floor that are limiting the pedal's range?

 

You're right...throttle is a cable in the 04s.

One thing you could try: Start from 0 MPH and floor it. What RPM does it shift at? If you don't actually have 100% throttle, you might find it shifts much lower than redline. Of course, you'll only notice this if you're significantly under 100%, but it sort of sounds like you are.

Not sure where the H4 shifts, but my H6 is probably 6300 or so.

 

The loss of power going up a hill... and further loss of power when it downshifts is a classic sign of a restricted exhaust. It is almost like it has a rev limiter.

A couple of ways to do further checks are:
1. With it idling in the driveway, try to rev the engine up toward 4000 RPM's. If it falls flat on its face or can't even make it to around 4000, suspect a restricted exhaust.
2. Connect a vacuum gauge to the intake manifold. Teeing in to practically any vacuum line that connects to straight manifold vacuum will work. While watching the gauge, rev the engine up and down. If on the rev down, you see the gauge go from vacuum to positive pressure, suspect a restricted exhaust.

Usually a restricted exhaust is caused by a catylitic converter that has shifted or turned in the shell or has just come apart internally. Make sure no one shoved an orange or potato up the tail pipe (i.e. vandalism). Also smashing any part of the exhaust against a rock or curb could partially close off the system.

Sometimes you can get a reduction in power by a timing belt that is off a tooth or two, but you can usually get it to rev high and it will show some increase in power when downshifting while going up a hill.

Additional Edit: After reading your last update, I remembered something similar that happened on one of my cars that had a converter problem. Once when I was trying to figure out why I had such low power, my engine came to life and suddenly I had full power. At the same time, I looked in the rear view mirror and saw a bunch of brown looking dust/smoke come out the back for just a few seconds. That is when I figured out that I had just burned up something in the exhaust and it had blown through the muffler. Later I took it to a muffler shop and when the worker had the converter off, he shook it and it made all kinds of internal noise. He said that the honeycomb had unattached from the internal mount and had shifted, causing the restriction. It would seem unusual for a newer OB to do that and if you do find that it is the converter and you live in the States, it might still be covered by the mandated Federal Emissions system warranty that all vehicles in the US must comply with. It is either 5 years or 8 years. That might be worth investigating further.

 

I THINK there was a recall to install a clip of some type on the CC cable - maybe that has slipped or is somehow misapplied and affecting the accelerator cable?

anyway - actually sounds like good news, once the accel linkage/cable is sorted out.

 

any updates?

 

I got had the same proble in my 2004 forester xt automatic. Also de engine light was on for about a half a year. The car would first hesite a lot to accelerate and a couple a day ago did not accelerate up a hill. my local mechanice say it could be two thing the flow meter (sensor next to airfliter) or the trotlee sensor. To check the flowmeter it is very easy just disconect the plug. I did it and the car runs prefectly so I know it is the flowmeter also I had a p0107 code before. If the probleme is still presente it is the trotle sensor