Subaru Outback Forums banner
1 - 10 of 10 Posts

·
Registered
2005 Outback ej25
Joined
·
4 Posts
Discussion Starter · #1 ·
Hi all,


I have a 2005 subaru outback ej25 4spd automatic sports shift AWD. 230,000kms.


Yesterday i went for a drive and the car has a serious lack of power under WOT.


Prior to this I had been noticing a shaking during acceleration under load up around 70-110kms. more noticeable up hills etc. unfortunately we were away on a trip and i had to drive the car like this for quite a bit.


Under advice i changed the plugs and leads but no change.
(plugs were very dirty and there was some oil on the outer leads that connect to the plugs)



Yesterday i went for a drive and the car has a serious lack of power under WOT.


In automatic the car can easily be be put in reverse and neutral.
and the car revs and idles fine in park and neural reving quickly and normally all the way to red - take your foot off the revs come back normally and the car idles fine.


But when i put it in drive and drive around 1st, 2nd, 3rd and 4th gear is no good.
Basically i put my foot all the way to the floor and the car moves - but increases speed very very slowly its like it has no power at all. tried changing to sports shift same problem, i can go through the gears all the way up to 4th but no true power in any gear.


Thanks in advance for any help.
 

·
Registered
Joined
·
19,513 Posts
When you apply more throttle ("put my foot all the way to the floor and the car moves - but increases speed very very slowly"), does the engine rpm increase significantly, but the car not accelerate, or is it that the engine doesn't seem to speed up in response to the throttle?

With the automatic, when you put the pedal to the floor, the transmission should downshift (if it's not already in 1st gear) and that would be accompanied by a speed up of the engine rpm.

If the engine rpm seems to respond to the throttle, but the car not accelerate accordingly, there's the possibility a drive axle has broken or pulled out of the respective differential. Depending on the symptoms, this could be a front axle, and all the drive is through the AWD transfer clutch, which can handle only so much torque before it slips.

There's a fuse slot in the engine compartment fuse box that, when a fuse is installed, it disables the AWD, namely, power to the rear wheels. (There's more on this in the Owners Manual, in the section on replacing a flat tire with the temporary spare.) If the symptom is that the engine speeds up but not the car, try inserting the AWD-disabling fuse and see what happens. If the car doesn't move at all, then the problem is in the front drive, and likely one of the front axles.

Just some ideas . . .
 

·
Registered
Joined
·
22,806 Posts
Hi all,


I have a 2005 subaru outback ej25 4spd automatic sports shift AWD. 230,000kms.


Yesterday i went for a drive and the car has a serious lack of power under WOT.


Prior to this I had been noticing a shaking during acceleration under load up around 70-110kms. more noticeable up hills etc. unfortunately we were away on a trip and i had to drive the car like this for quite a bit.


Under advice i changed the plugs and leads but no change.
(plugs were very dirty and there was some oil on the outer leads that connect to the plugs)



Yesterday i went for a drive and the car has a serious lack of power under WOT.


In automatic the car can easily be be put in reverse and neutral.
and the car revs and idles fine in park and neural reving quickly and normally all the way to red - take your foot off the revs come back normally and the car idles fine.


But when i put it in drive and drive around 1st, 2nd, 3rd and 4th gear is no good.
Basically i put my foot all the way to the floor and the car moves - but increases speed very very slowly its like it has no power at all. tried changing to sports shift same problem, i can go through the gears all the way up to 4th but no true power in any gear.


Thanks in advance for any help.
Did you use NGK plugs and high quality wires? That will result in pretty poor performance if you didn't. Subarus are very picky about their plugs and wires. Whats the story on timing belt service? I would't be mashing the go pedal till you make sure everything else is OK. Sounds like your Valve covers are leaking based on your comment about oil on the plugs. This can cause arching at the plug and cause performance issues also.
 

·
Registered
2005 Outback ej25
Joined
·
4 Posts
Discussion Starter · #4 ·
Did you use NGK plugs and high quality wires? That will result in pretty poor performance if you didn't. Subarus are very picky about their plugs and wires. Whats the story on timing belt service? I would't be mashing the go pedal till you make sure everything else is OK. Sounds like your Valve covers are leaking based on your comment about oil on the plugs. This can cause arching at the plug and cause performance issues also.
yep NGK platinum and good quality wires.
there is no missfiring or lumpy idle.
also it happens straight away as soon as you drive the car so im ruling out heatsoak.
 

·
Registered
Car: 2008 Tribeca, 2010 LGT, Sold: 2005 XT Limited
Joined
·
2,926 Posts
Hard to tell if this is a engine or transmission issue. Subie is covering transmission issue.

To me it sounds like it isn't reving when placed under load.

Have you scanned for any codes?

Could be knock sensor pulling timing or vacuum leak causing timing to get pulled when you are trying to drive under heavy load.
 

·
Registered
2005 Outback ej25
Joined
·
4 Posts
Discussion Starter · #6 ·
When you apply more throttle ("put my foot all the way to the floor and the car moves - but increases speed very very slowly"), does the engine rpm increase significantly, but the car not accelerate, or is it that the engine doesn't seem to speed up in response to the throttle?.
the revs do not increase quickly they seem to be matched with the power the car is making - rising accordingly

I tried the AWD fuse. The AWD light came on on the dash however all the symptoms are the same the car still drives with the lack in power and still has the vibration
 

·
Registered
Joined
·
19,513 Posts
That is strange.

The brake light circuit (downstream of the stop light switch) that conveys power to the light bulbs themselves also goes to the ECM, BIU and ABS controller. According to the service manual, each of these modules detects when there's power in that part of the circuit, that is, when the brake pedal is pressed and the switch is closed; however, the indicated detecting criteria (what the module is looking for) is basically

"When brake pedal is depressed: 10 — 13, When brake pedal is released: 0"

In all three cases, the modules do have functions or routines that are supposed to work when the brake is pressed, such as enabling the ABS, and the ECM, so it's understandable that there would be the connection between the brake light circuit and these modules. However, whether or not the bulbs are bad, the voltage in that circuit would appear to be either zero or close to the system voltage (~13V) when the brake pedal is pressed.

Interestingly, when the pedal is not pressed, and the brake light switch is open, the modules are still connected to the wiring downstream of the switch. (See attached wiring diagram.)

The modules are electronic circuits that operate on the basis of voltages and currents. Consequently, when the brake is not pressed, the modules (or at least one of them) might have some voltage in the circuit connected, internally, to the terminal going to the brake light circuit. If the bulbs are good, that voltage might be depleted (drawn down) by the low resistance to ground through the filaments of the bulbs. But if the bulbs are blown, that voltage might remain. It's that residual voltage that might detected and cause the ECM to limit engine function.

I've never come across any similar report between the brake lights being out and the engine not responding, other than this case and now the link to Mark's Auto Care. But again, both cases do not involve North American models, so it could be something unique to rest-of-world Outbacks.
 

Attachments

·
Registered
Joined
·
19,513 Posts
Another possibility:

I wonder if the cars that have experienced this problem have the tail lights on with DRLs. It's rare, but my 07 is set up that way, and I know that some other makes are as well. Because the symptom reported here is not a North American model, could it have continuous tail lights as well?

The reason I ask is because the tail light and brake light are part of the same bulb (or "globe") -- there's two filaments in the same bulb, one for the tail light, one for the stop light. If the stop light filament breaks and one end falls down onto the tail light filament (or a tail light filament falls onto the stop light filament, the stop light circuit could have full voltage on it. That voltage would be carried back, through the brake light wiring, to the modules. The ECM would see, say, 12 V at it's connection (pin C8 in the wiring diagram) and consider it as if the brakes had been applied. Perhaps when that is the case, the ECM is programmed to limit engine power when in gear.

Again, it's just another idea, for consideration, to try to explain this odd behavior.
 
1 - 10 of 10 Posts
Top