Urgent: 2000-2003 2.5 SOHC Octane Survey

[brus brother]

2.5 SOHC should run on 87 octane. I have had pinging from day one with my 2000 Legacy GT despite new plugs and gas filter, new MAP and knock sensor, seafoam injector and throttle body cleaner treatment, new windshield wipers etc.

This 2.5 SOHC engine was used from 2000 to late 2003 in a variety of models.

Despite best efforts of local tech, SOA suggests CT. gas at fault.

Please post your year, model, location and octane usage.

[Suzam]

MY01 Outback LTD Wagon, we use 87 octane year 'round and occasionally hear a slight ping under normal acceleration. Tried 89 octane for a time but still experienced the ping after a couple of tank fulls. Never had a ping that I considered extreme.

[Losiho]

Australia - MY99 Outback (same shape), I either use 95 or 98 Octane (RON).

[thingol]

Not mine, but my mother's.

 

2003 OBW, 87 all the way.

[cookie]

which is what I have and I run it on the lowest test with no pinging.

I'm in CA.

[~01~Outback]

01 Outback - Australia: ran on regular and had pinging under any load; started using premium 98 Octane, and pininging went immediately (less than 1/4 of a tank!)

 

I didnt think it was fuel at first, it sounds like timing lag, but timing is spot on and using premium kills the problem. Id be interested to hear a 3.0 running on regular, to see if it develops the same problem!

[brus brother]

My wife's 2005 OB non-turbo runs on the very same 87 octane with NO pinging. High test is pricey and if SOA is correct in their assessment of Connecticut gas, the spec. in the 2000 owner's manual should have included a disclaimer for CT. buyers. Perhaps SOA can still reprogram and flash the ECU to accomodate 87 octane.

01 Outback - Australia: ran on regular and had pinging under any load; started using premium 98 Octane, and pininging went immediately (less than 1/4 of a tank!)

 

I didnt think it was fuel at first, it sounds like timing lag, but timing is spot on and using premium kills the problem. Id be interested to hear a 3.0 running on regular, to see if it develops the same problem!

[subeman90]

had a prob with my old 02 LOB so i started using 89 and it went away. The dealer told me to do that once in a conversation with them about other issues. I said the book says 87 and he said....I know but...

 

From then on all I use is 89 in the cars in my sig. (except the xt because it doesn't run...)

[blatant]

87 all the time, and there are some big hills out here in Co and Az. No issues and no pinging, but again i drive this thing like i stole it and usually with the radio up to drown out other sounds that are most likely nothing. I'm paranoid as i own a jeep too. So the radio is my fix. runs like a top aside from slight seepage from the oil filter, which is not noticable in level and doesn't drip.

[nurseman]

i would put a good fuel system cleaner in and run high test gas for a while. if pings still you can put a small amount of tranny fluid in oil crankcase to quiet it down as well. if you put high performance plugs in you need high test gas. like iridium plugs.

 

dave

[doeleen]

2.5 SOHC should run on 87 octane. I have had pinging from day one with my 2000 Legacy GT despite new plugs and gas filter, new MAP and knock sensor, seafoam injector and throttle body cleaner treatment, new windshield wipers etc.

This 2.5 SOHC engine was used from 2000 to late 2003 in a variety of models.

Despite best efforts of local tech, SOA suggests CT. gas at fault.

Please post your year, model, location and octane usage.

 

Sorry about the ping problem! I use the highest rating for my 2005 Outback XT 2.5L.

 

Question: Do you go to the same place for gasoline or to several diff stations? Does the state of CT have diff gasoline regulations than other states?

[forester2002s]

2002 Forester: 87 Octane (RON+MON)/2 = No pinging.

 

BTW, a build-up of carbon deposits in the combustion chamber can cause pinging, even with the correct fuel. Try a gasoline additive for a while, and drive at high-speed for a few long trips. That might burn off the carbon deposits (if you have any), and get rid of the pinging.

[unverviking]

When we first bought our 01 we started using 89 Octane. When gas started getting expensive, we dropped back to 87. I always attributed the pinging with the car getting spoiled on the 89 and just not liking the 87. It's been pinging pretty regularly (with no ill effects, hopefully) until now... I changed the oil this weekend and put in a quart of Rislone. I've used Rislone before in my old Dodge Dakota, it pinged regularly using 87 also. The Rislone seemed to have helped in it, so I tried it on the Sube. No more pinging. I also used some fuel injector cleaner, but I've already gone through the tank I added cleaner to. I still don't have the pinging, so I'm suspecting the Rislone did the trick.

 

Any thoughts from the "gallery"

[brus brother]

Of those using Mobil gas, are you able to use 87 octane?

[subeman90]

I don't buy Mobil. it goes through my car like pi$$ water. Mileage always suffers for some reason.

[rizzo]

My wife's 2005 OB non-turbo runs on the very same 87 octane with NO pinging. High test is pricey and if SOA is correct in their assessment of Connecticut gas, the spec. in the 2000 owner's manual should have included a disclaimer for CT. buyers. Perhaps SOA can still reprogram and flash the ECU to accomodate 87 octane.

 

i bought my 03 OBS 2.5 at a subaru dealer in CT and they said to use 87. i don't know if it's the same pinging you're talking about, but when i accelerate or if the car was just started, the engine makes more noise than i would expect of a newer car. i'm guessing it's the pinging you're talking about. unfortunately, i can't really afford higher octane, although i'd like to switch, but i've heard that once you go to a higher octane, you can't really go back. i use nothing but 87. i'm wondering if the original owner used higher...

[brus brother]

Rizzo- The pinging doesn't start until the car is warmed up. You need that heat to allow for detonation. The pinging occurs under light load but if I floor it and beat the snot out of it there usually is no pinging.

01 Outback- Apparently the computer logic is different for the 3.0

Subeman- Can you say "false advertising"?

Blatant- turn the radio down. It only draws attention to the fact that you are driving a stolen car.

nurseman - I did fuel injector, throttle body and upper engine decarbon process without much difference.

forrester2002s- same as above but maybe the Canadian gas has different additives.

doeleen- 2.5 is stated in owner's manual to run on 87. I believe your 05 XT requires premium which is why I bought the missus the 05 OB Ltdi. CT and NY switched from MTBA to ethanol but this problem has been going on since before the switch.

unverviking- you may have had carbon buildup allowing for detonation but it is encouraging that you no longer have the problem whether it was from the injector cleaner or Rislone.

subeman90- I'll track the mileage. I will follow the SOA directions even if they insist it is the headlight fluid that needs changing and then challenge them for a rationale.

Thanks and keep those cards and letters coming in.

Any more comments from the cheap seats?

[scoobyclimbs]

87 and 92 no problems at all....in my '03 outback in Oregon

[themixtoo]

2.5 SOHC should run on 87 octane. I have had pinging from day one with my 2000 Legacy GT despite new plugs and gas filter, new MAP and knock sensor, seafoam injector and throttle body cleaner treatment, new windshield wipers etc.

This 2.5 SOHC engine was used from 2000 to late 2003 in a variety of models.

Despite best efforts of local tech, SOA suggests CT. gas at fault.

Please post your year, model, location and octane usage.

2003 BAJA, wife uses 87 octane all the time. When I tow something I use 92. Have not had a pinging or loss of power problem yet (40k on odo) Gary in Cleveland, Ohio

[Strakes]

1993 Legacy 2.2: 87 octane no problems at all

2002 Legacy 2.5: 87 octane no problems at all either.

 

About every 2 months of running 87, we run 93 octane in it for a tankfull. Don't know why we do this, but we always have. Maybe it's because we feel guilty of not giving our cars the "best" gas all the time.

[pdxboy]

I have a 2003 Outback 2.5 4-speed purchased new in Los Angeles that has had pinging problems since new. Not bad at all in cold weather, but starts knocking above about 60 degrees. Car is now in Portland Oregon. With windows up it is not that noticeable, but windows down - WOW! It's warming up here, so I'm headed to another dealer tomorrow to see if they can troubleshoot it. I have always used 87 octane (various brands) and the last dealer said to use 89 or 92 - whatever stopped the knocking. It did help, but I think that's crap - one of the reasons I bought this car was because it's a 4-cylinder that's supposed to use regular gas. I'll report the findings when the dealer is done with it.

[swc7916]

I have had 5 Subarus with the 2.5 liter engine and had no pinging with any of them with any brand of regular gasoline. I have used Arco, Safeway and Chevron with no pinging anytime and under any load.

[Andyman53]

I got a 2005 Impreza 2.5RS. I use 87 regular all the time and on the first few weeks i tried putting 89 and 93 and they dont' have any effect on my car. My car still accelerates the same and plays possum at the same times (Punch the pedal around 35 and see what happens eg. Merging) . I mainly use HESS because its cheap and not garbage. I say not garbage because i HAVE used value brands in my 94 Dodge Shadow and it BUCKS like a mechanical bull.

[brus brother]

Update:

In spite of using 4 tanks of 93 octane Mobil (car should run on 87 as per SOA), the car still pings under light load just at about the 35mph mark. 73,000 miles. Had new air and gas filter and plugs, timing checked and adjusted (off on cam from factory), decarboned with SeaFoam three times and throttle body cleaned. knock sensor changed. Aside from posting your octane and pinging experiences with 99-03 vintages, if anyone has any suggestions, please unstump me.

[gbhrps]

Gentlemen,

 

Not to befuddle the thread here, but is it possible that this "pinging" is really the dreaded piston slap inherent in Subie engines that some of you are hearing? My 97 OBW had the slap, but no pinging/preignition on regular 87 octane fuel. My 02 OBW has the slap on cold mornings until warmed up, but no pinging/preignition, again using 87 octane.