What causes the 'chuffing' noise older Subarus make?

[Hachiroku $B%O%A%m%/(B]

I have an '89 1.8L

Like all old Suby's it makes that 'chuffing' noise that sounds like a very
large eggbeater.

What causes this? I realize this has to do with the boxer design, but
there must be a reason why it becomes more pronounced with age.

 

[swrt]

Subaru, being the very interestingly designed companym it is, has mad
the boxer engine to leak a precise, but exact amount of engine oil ont
the engine. The is a groove the runs along the side of the engine t
divert this oil to different parts of the engine. The oil then drie
and forms into an insulation for the motor. The more you drive, th
more miles you get on your vehicle, the more need for an engin
protectant... and the more the oil leaks to create this layer o
"insulation.
Sounds false but i can garentee you that it is true due to the fac
that the source of this info is from a 60 year old combustion eginee
who owns his own engineering firm and is an automotive collector
particularly subaru

 

[Bugalugs]

Subaru, being the very interestingly designed companym it is, has made
the boxer engine to leak a precise, but exact amount of engine oil onto
the engine. The is a groove the runs along the side of the engine to
divert this oil to different parts of the engine. The oil then dries
and forms into an insulation for the motor. The more you drive, the
more miles you get on your vehicle, the more need for an engine
protectant... and the more the oil leaks to create this layer of
"insulation."
Sounds false but i can garentee you that it is true due to the fact
that the source of this info is from a 60 year old combustion egineer
who owns his own engineering firm and is an automotive collector,
particularly subaru.

I've just been out and checked out the dried oil on my garage floor and
it makes no noise at all.

 

[Proctologically Violated©®]

I have an '89 1.8L

Like all old Suby's it makes that 'chuffing' noise that sounds like a very
large eggbeater.

What causes this? I realize this has to do with the boxer design, but
there must be a reason why it becomes more pronounced with age.

Sort of like a raspy chugging? If it's the same as what I notice, I hear
that in older vans and pickups as well.
And, slightly, upon accelerating uphill, in my 04 Nissan Frontier.

Been meaning to ask about this myself.
--
------
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The Solution is so simple--and inexpensive!

entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs

 

[David]

I have an '89 1.8L

Like all old Suby's it makes that 'chuffing' noise that sounds like a very
large eggbeater.

What causes this? I realize this has to do with the boxer design, but
there must be a reason why it becomes more pronounced with age.

Wear in the valve train?

 

[Bugalugs]

I think you could look at a combination of the Firing order, the flat 4
layout, the routing of the exhaust, and the aging/rusting out of the
whole exhaust system.

You get the same sound from the old VWs (the 'real' ones)

 

[Carl 1 Lucky Texan]

I have an '89 1.8L

Like all old Suby's it makes that 'chuffing' noise that sounds like a very
large eggbeater.

What causes this? I realize this has to do with the boxer design, but
there must be a reason why it becomes more pronounced with age.

Hmmmm - lots of people report great success at cleaning out carbon using
SeaFoam, Berryman's B12, etc. Some of the oldtimers at
www.ultimatesubaru.org claim soobs carbon up badly with age - maybe the
'chuffing' is valves leaking due to carbon buildup?

dunno


Carl

 

[Porgy Tirebiter]

I think you could look at a combination of the Firing order, the flat 4
layout, the routing of the exhaust, and the aging/rusting out of the whole
exhaust system.

You get the same sound from the old VWs (the 'real' ones)

You are right on target
The Subaru "Boxer" design is damn near a complete rip-off of VW..without the
air cooling.

 

[Rick Courtright]

Like all old Suby's it makes that 'chuffing' noise that sounds like a very
large eggbeater.

Hi,

If you're describing the noise mine started making, it could be an
exhaust leak. In my case, a '90, it was located at the junction between
the "Y" pipe and the section w/ the second cat. Subaru in its infinite
wisdom chose to ignore the fact the rest of the world generally bolts
their exhaust systems together quite tightly w/ standard bolts and used
a "spring loaded" bolt arrangement at that joint. It allows the system
to flex, which causes wear of the "donut" seal in there. Eventually it
could leak. Suggest new bolts AND springs if you replace the donut.

Also check that the nuts holding the exhaust system to the heads are
tight--if they're really loose, those gaskets could be toast--and the
muffler's in good shape. That "old VW" noise always responded well to a
new $29.95 muffler (those were the days, eh?) on my air-cooled Bugs. A
similar noise responded well to a new muffler on my old Toyota p/u
(would that IT was ONLY $29.95!)--the old muffler didn't look bad while
installed, but the front pipe came out in my hand when I removed it.
Looking inside, rust had done quite a number.

Rick

 

[Hachiroku $B%O%A%m%/(B]

On Tue, 10 Jul 2007 20:13:42 -0800, Porgy Tirebiter wrote:

Porgy Tirebiter! Well, isn't that Public School!

BTW, shouldn't it be Tyrebyter? I had an Olde English Sheepdog, and his
AKC Registered name (Honest to God) was Arthur Tyrebyter, back in the late
70's!

 

[Scott Dorsey]

On Tue, 10 Jul 2007 20:13:42 -0800, Porgy Tirebiter wrote:

Porgy Tirebiter! Well, isn't that Public School!

No, he goes to Moore Science High School. "More class for more kids for
Moore Science" I think.
--scott

"Where's your school spirit, Muddhead?" "It's in the rumble seat, you
want a snort?"

 

[Eddie Haskell]

No, he goes to Moore Science High School. "More class for more kids for
Moore Science" I think.
--scott

"Where's your school spirit, Muddhead?" "It's in the rumble seat, you
want a snort?"

You guys are right! It's from Firesign Theater and old radio days.

 

[Hachiroku $B%O%A%m%/(B]

You guys are right! It's from Firesign Theater and old radio days.

I thought that sounded familiar.

But I guess I was too stoned at the time...

Anybody seen Ralph Spoilsport?

 

[Guest]

You are right on target
The Subaru "Boxer" design is damn near a complete rip-off of VW..without the
air cooling.

No, it's just the same layout. The VW had a central camshaft
and pushrods and rocker arms, the Soob has an overhead cam setup. The
VW had a camshaft-driven oil pump, the Soob's runs off the cam belt
(IIRC). The VW had separate cylinders; the Soob has a cylinder block
on each side.
Saying it's ripoff of the VW is like saying that a Toyota 4-
banger is a ripoff of a Continental Industrial 4-banger. The boxer
design has been around a long, long time and has been used in
airplanes since before the Germans came up with the VW. It's still
being used in airplanes. The VW is much closer to being a ripoff of
those aircraft engines.

Dan

 

[Carl 1 Lucky Texan]

I thought that sounded familiar.

But I guess I was too stoned at the time...

Anybody seen Ralph Spoilsport?

He's busy defoiliating the victory garden.




Carl

 

[Carl 1 Lucky Texan]

No, it's just the same layout. The VW had a central camshaft
and pushrods and rocker arms, the Soob has an overhead cam setup. The
VW had a camshaft-driven oil pump, the Soob's runs off the cam belt
(IIRC). The VW had separate cylinders; the Soob has a cylinder block
on each side.
Saying it's ripoff of the VW is like saying that a Toyota 4-
banger is a ripoff of a Continental Industrial 4-banger. The boxer
design has been around a long, long time and has been used in
airplanes since before the Germans came up with the VW. It's still
being used in airplanes. The VW is much closer to being a ripoff of
those aircraft engines.

Dan

Interesting thread with a LOT of flat4 history stuff;

http://www.ultimatesubaru.org/forum/showthread.php?t=64014



Carl

 

[John S.]

I have an '89 1.8L

Like all old Suby's it makes that 'chuffing' noise that sounds like a very
large eggbeater.

What causes this? I realize this has to do with the boxer design, but
there must be a reason why it becomes more pronounced with age.

More than anything else it is the odd exhaust sound resulting from the
firing order on a flat engine. VW, Porsche, Corvair all have a unique
exhaust note that becomes even more pronounced as the exhaust system
develops leaks and the muffler muffles less, etc. Also contributing
to the Subaru engine exhaust sound being noticable is that it is
watercooled and as a conseqnence much quieter than it's aircooled
cousins. The exhaust note isn't covered up by the lawnmower-like
sounds of a VW, Porsche or Corvair engine.

 

[Steve]

No, it's just the same layout. The VW had a central camshaft
and pushrods and rocker arms, the Soob has an overhead cam setup. The
VW had a camshaft-driven oil pump, the Soob's runs off the cam belt
(IIRC). The VW had separate cylinders; the Soob has a cylinder block
on each side.

All of which Subaru EVOLVED to. IIRC, the first Subarus were practically
VWs with coolant jackets. Just like the first Toyota Land Cruiser engine
was a Chevy straight-six (license-built) that then evolved away from its
Chevy origin, albeit much more slowly than Subaru evolved.