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Does your Forester's N/A (non-turbo) gas engine pink/knock when using 87 AKI fuel?

  • nYes, my Forester's N/A engine pings/kocks when using 87 AKI fuel.

    Votes: 8 42.1%
  • No, my Forester's N/A engine does not ping/knock when using 87 AKI fuel.

    Votes: 11 57.9%
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Premium Member
2015 Highlander AWD XLE 6AT
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4,255 Posts
Discussion Starter #1 (Edited)
Trying to get an idea of how many forum members have a ping/knock problem when operating their Forester with a normally-aspirated (non-turbo) engine using 87 AKI (~91 RON) fuel.

FWIW, my '09 Forester X does not ping/knock. I tend to use 87 AKI fuel in the winter and 88 or 89 AKI in the summer (at low elevations).

HTH,
Jim / crewzer

P.S. Sorry about the typos in the poll questions. I have no idea about how the "n" got teleported... :icon_redface:
 

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2009 Forester (MT)
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226 Posts
Trying to get an idea of how many forum members have a ping/knock problem when operating their Forester with a normally-aspirated (non-turbo) engine using 87 AKI (~91 RON) fuel.

HTH,
Jim / crewzer

P.S. Sorry about the typos in the poll questions. I have no idea about how the "n" got teleported... :icon_redface:
I don't use anything but 87 on my 2009 Forester as shown in the owner's manual. No pinging whatsoever noticed. However, fuel additives aren't used in Alaska. Maybe that makes a difference?
 

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2005 Impreza RS Wagon Auto
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3,658 Posts
No ping on my '99, just obvious mpg difference when they load the ethanol on.
 

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2020 Forester Touring
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50 Posts
YES and I just noticed it.

Okay... so my partner is a mechanic but I'm the one that noticed it.

First off, I bought the non-turbo BECAUSE I didn't want to have to commit to a higher octane. Then yesterday it was nice enough to have both the windows and the sunroof open and I noticed that if I was coasting and lightly pressed the accelerator, it would knock about 3 times before the engine rev made it too loud to hear anymore.

I duplicated this over the course of an entire day... after stopping and starting... and shutting down the engine for a few hours... every known option.

I do not notice it at initial takeoff from a full stop, but I think this has more to do with sound of the engine than it not actually occurring then. It also doesn't happen if the car is in neutral/park and being revved... it has to have a load on it.

I do use the lowest octane... but buy quality gas (Actually, my partner works as a mechanic for a gas company, and we get gas from them. They do put 10% ethanol in, but the only place in town that doesn't has the WORST gas.).... and all documentation from Subaru seems to say that 87 is just fine.

So, in closing... my partner and every other mechanic I've heard from say that knocking and pinging on any engine is a bad thing... that it can cause damage... Granted, the damage will be after the warranty runs out, most likely... but damage none the less. So, anyone get their dealership to fix this?

I've had 0% luck with my local dealer fixing things... (see my threads on my AC) and know that this won't be able to be heard in the downtown area where the dealership is... so unless I know they know about this issue, then I may just be out of luck. :icon_sad:
 

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09 forester
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186 Posts
ive had the occasional ping, and i noticed it when i purchased gas from one particular gas station. my friends land rover did the same thing from this station. no ping if i buy from any other place regardless of brand.
 

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2007 Forester L.L. Bean
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5 Posts
Our 07 ll bean does ping on 87 as well, but I've noticed that it seems worse on some brands of fuel than others. I'll have to try and keep track of which places are the worst offenders and avoid them in the future or bite the bullet and spring for premium fuel which seems to eliminate almost all signs of pinging.
 

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Premium Member
2015 Highlander AWD XLE 6AT
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4,255 Posts
Discussion Starter #10 (Edited)
mreding,

Without implying that I would agree with their position, Subaru may tell you that your car's operation is "normal". Page 7-2 in my owner's manual includes this statement:

Do not be concerned if your vehicle
sometimes knocks lightly when you drive
up a hill or when you accelerate.
Your car might be running right on the ragged edge. Accordingly, it might be worth trying 88-89 AKI gas (mid-grade) in your car in the summer (~May through ~October). It's a fairly inexpensive experiment to run, and the reduced (eliminated?) knock and/or improved fuel economy might offset the extra fuel cost. You should be able to switch back to 87 AKI fuel ("regular") in the winter (~Nov through ~Apr).

I hope you'll keep up posted on results should you decide to try this.

HTH,
Jim / crewzer
 

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130 Posts
The poll is closed, so I can't vote :icon_frown:

My 09 pings terribly on 87. I took it to the dealer and he immediately acknowleged the ping and agreed that if not corrected damage to the engine would result.

My car spent a total of 7 days at the dealership with no success in fixing the problem. I wrote Subaru about the problem and they replied with a case number, but have done NOTHING about the problem.

89 didn't fix the problem, so I'm running premium.

It's obvious to me that Subaru doesn't give a damn.

Yes, I'm a little bitter bout this....
 

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Premium Member
2015 Highlander AWD XLE 6AT
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4,255 Posts
Discussion Starter #13
Pings and Knocks are two different things, no?
No. They're pretty much the same thing (aka "detonation"), where the air-fuel mixture is ignited by the spark plug but then burns erratically, resulting in the metallic "pinging" or "knocking" sound. Depending on the severity, the effects range from virtually nil (except for the aggravating noise) to damaging.

Pre-ignition -- ignition of the air-fuel mixture before the spark plug fires -- is different. This condition is not good.

HTH,
Jim / crewzer
 

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2015 OutBack Ltd
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2,929 Posts
FWIW, my '03X has always lightly pinged when going up hills in the highest gearing that AT allows.......

The pinging is very slight and sounds like a marble clinking around under the hood but disappears as soon as the load on the engine is removed or the trannie steps down so the engine revs go up.........and having just passed 130K miles with no issues, I have to assume that this is normal.

I've had my Forrie tuned at several Subi dealers and neither asked about it or had it after bringing it to delivery dealer in NJ.....who said it was normal so long as it is limited to the situation as described......


Steve
 

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2014 Forester CVT
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95 Posts
2004 Forester X

I have noticed pinging on mine as well, same situation as first described you just lightly push on the throttle under very little load and you get some ping.

My engine just had the heads done, replaced the plugs and fuel filter. I have a cold air intake and I was going to put back the stock box to see if it still there, it seems more noticeable with the CAI and this makes sense cause the engine is louder.

Being an electronic ignition system how would one check the timing or fix if needed ? If anything I think maybe a sensor is faulty, maybe 02 or air temp control may be out of tolerance ?

I am at 190000 Kms and plan on keeping this car for another 100000 Km :)

Any suggestions tips :)
 

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Ah crap.. I'm back with my 05 XS
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8,294 Posts
Yeah I have this as well. It's been like this since before 30k. Haven't tried higher than 89.
 

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2016 Forester XT AT
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1,295 Posts

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2003 Forester X Auto
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947 Posts
Mine did it for a while after I got it. Used Seafoam to clean the upper engine, increased to premium fuel for a couple of tanks and gave it an Italian tune up once in a while. Pinging went away and had no problems after that on 87 octane. If you drive it sedately, or in alot of stop and go traffic, you might get some carbon build up which can cause the pinging/knock under light load.
 
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