What causes the 'chuffing' noise older Subarus make?

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.

Reply to
Hachiroku
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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.

Reply to
swrt

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

Reply to
Bugalugs

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.

Reply to
Proctologically Violated©®

Wear in the valve train?

Reply to
David

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)

Reply to
Bugalugs

Hmmmm - lots of people report great success at cleaning out carbon using SeaFoam, Berryman's B12, etc. Some of the oldtimers at

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claim soobs carbon up badly with age - maybe the 'chuffing' is valves leaking due to carbon buildup?

dunno

Carl

Reply to
Carl 1 Lucky Texan

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

Reply to
Porgy Tirebiter

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

Reply to
Rick Courtright

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!

Reply to
Hachiroku

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?"

Reply to
Scott Dorsey

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

Reply to
Eddie Haskell

I thought that sounded familiar.

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

Anybody seen Ralph Spoilsport?

Reply to
Hachiroku

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

Reply to
Dan_Thomas_nospam

He's busy defoiliating the victory garden.

Carl

Reply to
Carl 1 Lucky Texan

Interesting thread with a LOT of flat4 history stuff;

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Carl

Reply to
Carl 1 Lucky Texan

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.

Reply to
John S.

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.

Reply to
Steve

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