Is it the gas?

I’m getting this weird noise now around 1800 and 2500rpms where it sounds like a rattling when accelerating. Back in the day I believe it was called dieseling a sound that came when cheap gas was used. I have only been using Shell 89 and at times when it was affordable 93. Anyone have any ideas or suggestions please.

 

 

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First thing that gives a rattle is a heat shield that's loose somewhere. Check that and exhaust clamps. Go around and look for other parts that aren't tied down correctly.

I had issues with my Outback. Turned out i had cracks in the mid pipe. Peek around.

Dieseling is when a gas engine runs away under compression. You can turn the motor off but it keeps running because the fuel is igniting under compression rather than igniting due to spark.

Not the gas.

 

Some of the more common sources of "rattle":

 

1. Transmission ground wire is touching the air box.

2. Muffler baffle weld has broken.

Not the gas.

 

Some of the more common sources of "rattle":

 

1. Transmission ground wire is touching the air box.

2. Muffler baffle weld has broken.

 

In my sloppy reading I first read "2. Muffler bearing..."

I will be taking it in hopefully over the weekend

Not the gas.

 

Some of the more common sources of "rattle":

 

1. Transmission ground wire is touching the air box.

2. Muffler baffle weld has broken.

 

Just wondering why you are using anything but 87 gas in the first place?

Just wondering why you are using anything but 87 gas in the first place?

 

I have to say i originally was using 87 but to me the car drove like crap 89 feels a lot better and 93 feels like better than that IMO.

I have to say i originally was using 87 but to me the car drove like crap 89 feels a lot better and 93 feels like better than that IMO.

OoooooK!

 

Tell us what you really think!

 

Laughing at oneself and with others is good for the Soul![emoji2]

... i originally was using 87 but ... 89 feels a lot better and 93 feels like better than that IMO.

 

Of course. We all know that the butt-dyno never lies! Besides, what does Subaru know about the engines they design and build?

Any update on this?

 

I had a very similar rattle on my previous car which was 2.5i and it was the engine torque causing the bolts connected to the frame to loosen and rattle during accelaration. Mind you that a previous subaru service shop didn't tighten them properly after some other issue.

Not dieseling..... pinging, knocking.... preignition. Caused by premature ignition of fuel. New cars with all the sensors, and electronic adjustment of the ignition, it’s pretty rare today...... lower octane fuel burns hotter than higher octane.

Every manufacturer that builds cars will all tell you the same thing...if the car requires 87, using 89 or 93 will do NOTHING to make the car run any different and performance increases are nil. The car's engine and computer tuning are very specific to 87. By spending the extra money, your seat of the pants dyno makes "you" feel better. However, in reality, it doesn't make any difference...especially on a Subaru!

Every manufacturer that builds cars will all tell you the same thing...if the car requires 87, using 89 or 93 will do NOTHING to make the car run any different and performance increases are nil. The car's engine and computer tuning are very specific to 87. By spending the extra money, your seat of the pants dyno makes "you" feel better. However, in reality, it doesn't make any difference...especially on a Subaru!

 

Not true... I once put race fuel in mine, and my 0-60 time was 2.8sec.

... I once put race fuel in mine, and my 0-60 time was 2.8sec.

 

With an emphasis on "once"! Besides, nitromethane doesn't count ... especially when engine life must be measured in minutes!

Not true... I once put race fuel in mine, and my 0-60 time was 2.8sec.

 

Every manufacturer that builds cars will all tell you the same thing...if the car requires 87, using 89 or 93 will do NOTHING to make the car run any different and performance increases are nil. The car's engine and computer tuning are very specific to 87. By spending the extra money, your seat of the pants dyno makes "you" feel better. However, in reality, it doesn't make any difference...especially on a Subaru!

 

I'll tell you that my stock '01 Outback EJ25 pings under light load (uphill grade) in 5th gear running 87. When I run high octane it does not. I don't like engines that ping so I run higher octane in this car to avoid that. If it didn't ping I probably wouldn't bother.

One thing I noticed on my 01 Outback similar to what you describe was a rattle of the y-pipe heat shrouds. At about 1800 rpm I would get this metallic ratty hollow rattle, but only about that narrow rpm range. It might be something that applies to your Legacy - worth crawling underneath and doing some fist bumps and taps on parts to see about duplicating it. I also like to drive alongside concrete barriers (when it is safe to do so) to help amplify or reflect the sound so I can hear it more clearly. Good luck! I hate mystery squeaks and rattles!

I'll tell you that my stock '01 Outback EJ25 pings under light load (uphill grade) in 5th gear running 87. When I run high octane it does not. I don't like engines that ping so I run higher octane in this car to avoid that. If it didn't ping I probably wouldn't bother.

 

You cannot compare a 2001 engines performance to that of a 2017-2018. The technology is far different today than that used 17 years ago. For a 2001, it may make total sense.

Most of the time this issue is the Heat Shield on the Exhaust rattling. A simple fix. Get under the car, tap on the heat shielding until you find the loose sections, buy a couple Metal Pipe Clamps and tighten them down over the loose sections...