02 Outback bucking on acceleration

[Ionlyhave3suubs]

My 02 Outback started "bucking" on acceleration recently. The car has 122k miles on it now. No CEL lighting up. the bucking stops if you downshift enough to bring the RPMs way up. 5spd. Any ideas? This is a new condition. I have had the car since 90K. It has been running great up until recently.

[Fairtax4me]

Sounds like it needs a tune up.

 

Misfiring at low rpm under load. Usually caused by poor spark from old plug wires or worn/fouled plugs.

[idosubaru]

EJ25 or H6?

 

H6 had some TPS issues around 02 I believe that might cause some funky shifting like this.

 

otherwise i'd agree about tune up:

 

how old are the plugs and wires?

are they subaru wires?

any check engine lights or work at all in the past year or so?

 

if they've never been replaced i'd consider new Subaru wires and NGK plugs in the near future. the ignition is not very forgiving of aftermarket parts, i'd stick with OEM on those two items.

[ericem]

I think he has a 5spd manual he means.

[idosubaru]

I think he has a 5spd manual he means.

oh yeah, good call. 5 speed also means it's not an H6 then too, has to be a 4 cylinder.

 

the TPS issue is an H6 thing, don't think it's an H4 issue.

 

so - back to plugs, wires, and any engine light or work in the past year?

[nipper]

When in doubt do a tuneup first, then we go on from there

[Ionlyhave3suubs]

Sorry left out those details. It is a SOHC 2.5 4cyl, 5spd manual. Unknown mileage on the plugs and wires. Could be the originals, I bought the car with around 90k, so other than regular oil changes, I don't have much on the maintainence history. I have only done oil changes on this car and clutch (and related parts). I have done nothing to the ignition components. On my older suubs I have always gone with the OEM wires and NGK plugs and plan to do so on this one as well. While on the topic, what feedback do is out there on the the different grades of NGK plugs. The last couple of times I have gone with the iridium plugs. Am I wasting money on something I don't need. Are the cheaper plugs suitable, last as long?

[Fairtax4me]

Any NGK plug will do fine.

 

You are 17k miles overdue for a timing belt change. Basically driving on borrowed time with the 2.5 going past a belt interval. If it breaks, your gonna be out of a couple grand to get that engine running again.

[nipper]

Just go with whatever subaru recomends for the car, anything more really is throwing money away on a subaru, as sometimes they can give the car indigestion. The waist spark ignition can sometimes be touchy about plugs.

 

Dont forget the PCV valve.

[nipper]

Any NGK plug will do fine.

 

You are 17k miles overdue for a timing belt change. Basically driving on borrowed time with the 2.5 going past a belt interval. If it breaks, your gonna be out of a couple grand to get that engine running again.

 

HELL YES!

 

I missed that as posts crossed. You may even be seeing that start to show up a little bit.

 

a grand is on the low side depending upon damage done.

[Ionlyhave3suubs]

Timing belt is on the to-do list. Am I mistaken in thinking that the 02 SOHC 2.5 is a non-interference type engine? The timing belt was put on the back burner to my 97 OB with bad headgasket. (had to have something to drive while fixing 97).

 

I know BAD things happen on the 2.5d when the timing belts fail (fortunately not from personal experience) but I was under the impression that yes you can get stranded, but no major engine damage (bent valves, piston damage, etc.) on the non-interference engine with belt failure.

[nipper]

Almost all engine now are interference, especially with multi-valves.

 

They have been interference since the DOHC came out, and i think the 2.2 (just an fyi) since 97.

[Ionlyhave3suubs]

Thanks, Timing belt and tune-up will be my next project. I just need to get replacement transmission fluid to cooler hoses purchased and installed in 97 and I'm ready to tear into the 02. Unfortunately the parts stores were closed when I discovered the leak.:-\

[nipper]

Thanks, Timing belt and tune-up will be my next project. I just need to get replacement transmission fluid to cooler hoses purchased and installed in 97 and I'm ready to tear into the 02. Unfortunately the parts stores were closed when I discovered the leak.:-\

 

 

Make that the 1st project of that list. You are at where some idlers may start failing.

[Cougar]

As far as the bucking problem goes the trouble may be due to lack of fuel pressure. If you haven't replaced the fuel filter I suggest you replace it. If that doesn't help then you way have to replace the fuel pump. If climbing a hill makes the trouble happen then the fuel pump may be getting weak.

[Olnick]

If I may stray off topic for just a moment--congrats Cougar on your 5000th post! Merry Christmas!

[Rooster2]

It is possible that you may have bought a tank of gas that is tainted with water. Water doesn't burn well, and can cause the bucking that you are encountering. Suggest you add some "dry gas" additive to the fuel tank. It just may solve your problem.

 

Not long ago, a gas station near here had a bad seal on the fill pipe at ground level where the transport pumps gas into the tank. The bad seal allowed a lot of rain water to enter the tank. The result was a number of cars stalled just blocks from the station. That is just a severe example of what can happen.

[River19]

I just went through months of this issue, to the point where we had bucking, small backfires etc. with our 2003 OB 2.5L Auto.......from my experience you have gotten good advice on here, start with the ignition system.

 

I had the coil replaced as it threw a code on the coil, it kept happening, bucking under acceleration and deceleration from highway speeds down exit ramps (once you tried to get back on the gas it would pop and buck and backfire etc.).

 

Then I replaced the plug wires myself and whammo.......it cured all. Taht fix has lasted about 10K miles and 3 months (yes we drive a lot.....car as 162K on it).

 

The other night it started happening again under load at low rpm like when slogging along at 38-42mph when it doesn't know whether to be in OD or not and slogs along. I'm thinking I should have done the plugs as well when I did wires........I think they have maybe 50-70K on the plugs.......I'll have to check my records.

 

Hopefully that is it.......cheap fix. Of course now I'm leaking a little coolant as I overfilled the damn resevoir the other day...........jackass I am.

[nipper]

If there is oil on the sparkplug boots, this may make it come and go too. The valve cover buckets are leaking and will cause the voltage leak to come and go in the right conditions.

[Ionlyhave3suubs]

I picked up the timing belt stuff, plugs and wires today. Fixed the trans line leaks on the "97. Ready to get the "97 state inspection tomorrow and get started on the timing belt and ignition components tomorrow (did not drive '02 today drove my gas sponge {suburban}).

 

I have a Haynes manual for second generation Legacy but not for third gen. Is the timing belt procedure the same as for a second gen SOHC (such as 2.2)?

 

Is there something I need to know getting in to this project? All of my experience with EJ series timing belts have been 2.5D engines.

 

Do I need to just break down and buy a book for gen3 Legacy?

[nipper]

http://www.subaruforester.org/vbulletin/f66/timing-belt-pump-change-14416/ SOHC

 

That is a forester but they are all the same.

[Ionlyhave3suubs]

Ha! tell that to a Forester lover! Thanks for the link.

[johnceggleston]

I picked up the timing belt stuff, plugs and wires today.

 

I have a Haynes manual for second generation Legacy but not for third gen. Is the timing belt procedure the same as for a second gen SOHC (such as 2.2)?

 

any idler part you do not replace will be expected to go another 100k miles with out failure. that is a lot of miles, 225k, on a timing idler. most folks replace the idlers that are making any noise at all. but any one of them could start making noise in 10k miles and then be expected to go another 90k with out failure. my point is if at all possible replace ALL idlers, tensioner and water pump just to be sure.

 

the ej25 SOHC process is the same as the ej22 but the tooth count is probably different. you will want to confirm that. and be sure to torque the crank bolt to 125 ft lbs minimum, i use 140 ft lbs.

 

question for all:

does the crank bolt get 30 wt or anti-seize before torquing or go int dry?? i may have used lock tight but i can't remember. but dry vs ''lubed' will change the actual final torque.

[River19]

Can't answer the torque question.........but wanted to add that I just checked my records on the last time my plugs were replaced......12/12/08 111K miles and now almost exactly 2 years and 50K miles later I'm getting the bucking again. So after I do plugs I would have replaced the coil, wires and plugs all within the past 3 months or so, bucking should stop cold.

 

Now if I could just get my dash lights working again........:-\

[vasy]

any idler part you do not replace will be expected to go another 100k miles with out failure. that is a lot of miles, 225k, on a timing idler. most folks replace the idlers that are making any noise at all. but any one of them could start making noise in 10k miles and then be expected to go another 90k with out failure. my point is if at all possible replace ALL idlers, tensioner and water pump just to be sure.

 

the ej25 SOHC process is the same as the ej22 but the tooth count is probably different. you will want to confirm that. and be sure to torque the crank bolt to 125 ft lbs minimum, i use 140 ft lbs.

 

question for all:

does the crank bolt get 30 wt or anti-seize before torquing or go int dry?? i may have used lock tight but i can't remember. but dry vs ''lubed' will change the actual final torque.

 

According to FSM, crank bolt on a 2.5 should be torqued to 123 - 138 ft.lb, with light weight oil on both the bolt and the hole the bolt goes into. I used 140 ft.lb with Harbor Freight torque wrench on mine, with oil as mentioned.