73 bus anyone know what this sound is?

Oct 18, 2005 9 Replies

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Kind of a high pitched chirp. You can hear the hard drive of the laptop on the recording.



The mic starts out in the cab, then I move it into the engine compartment in the last 1/8th of the recording.



Sounds to me like there is a valve leak? High pitched sounding chirp



That baby sounds sweet, I don't hear anything. Sounds slightly rough like my beetle. I thought the beetle was bad.. Is this generally how a VW is supposed to sound? I just thought they were more quiet. I'm going to post a .wav of my beetle engine tommorow.

I'm no expert but it sounds like your valves need to be adjusted. What is the mileage on the engine and what oil are you using. What climate are you in?

Which bus engine is it? 1770 , 2000 or a T1 1600?

1700cc 1973 bus

10w30 oil

valves were adjusted 0 miles ago (new heads)

exhaust = .08 intake = .06

Why are you using 10w30 oil? You should use monograde 30W...in my opinion :-) Do you like oil leaks?

It will work smoth if you use SAE 30W

Joao

72 Super 1302

I write SAE 30 monograde oil, because is formulated to meet engine lubricating and cooling requirements between 4° C and 40° C.

Joao

72 Super 1302

Just posted my engine recording:

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new sound sample uploaded.

first on the left side of engine then on the right side of engine, then from top of the engine compartment..

high pitched chirp twice per crank revolution..

Jen

I did some more listening to the engine.

#1)yes, it will run. #2)the sound (chirp, like vaccum or pressure) alternates between left/right of engine #3)the sound is eliminated from the left side of the engine when I remove the plugs from the left side

ok... sources of input and output from the sides of the engine:

1)balance tube for air. connects to "master" output on top of left side carb. connnects to top of left side manifold. connects to top of right side manifold

#2)"balance" tube for brake booster. this is at the base of each manifold, they are connected by metal tube. brake booster connects to this tube.

#3)EGR tube. EGR isn't connected (crimped off before it goes to exhaust). This connects front(of car) of manifolds together, T to exhaust is crimped, but manifolds are connected... I didn't put new gaskets between the tube and the manifold,

#4)EGR ?valves? on manifolds. These are vacuum diaphragms on the outer side of each manifold.

#5) bad seal between carb and manifold? (on both sides?)

#6)bad seal between manifold and head? (both sides?)

Exhaust: sounds like the sound is on top of the engine, not on the bottom.

#7)exhaust output, exhaust leak. two ports on bottom of each head.

Any ideas? I think the sound may be tied to the manifolds and EGR valves on the manifolds.

Jenny

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