Air leak sound at shut down

[rhodesm]

Hi all. When I shutdown my Kohler engine (on Cub Cadet tractor), I hear what sounds like air rushing/leaking that pulses in sync with the crank (5 second video link below). It may be happening while it's running too...just not sure I can hear it. Has been doing this for a few months. I don't think it's affecting the power output, but not certain. Any thoughts and comments would be greatly appreciated!

<-- (Link to 5 second video of the sound)

Engine
Kohler Courage Pro
Model SV820S
Spec No. SV820-0011
23 HP
Built Feb. 2008

Tractor
Cub Cadet Z-Force 48
Model 17AF3AGV010
Built Mar. 2008

 

[Rivets]

Sounds like a blown head gasket.

 

[rhodesm]

Sounds like a blown head gasket.

Thank you.

 

[bertsmobile1]

Or a loose spark plug or a loose muffler or the breather fallen off ( a bit harsh for that )
Pull the spark plug take photo & post .
Blown head gaskets externally generally cause a lean burn so the plugs are near white

 

[rhodesm]

Or a loose spark plug or a loose muffler or the breather fallen off ( a bit harsh for that )
Pull the spark plug take photo & post .
Blown head gaskets externally generally cause a lean burn so the plugs are near white

Thank you for helping. Attached are pictures of both spark plugs. Neither appear white to my untrained eye.

 

[bertsmobile1]

Way too lean
So you either have a blown gasket ( both sides ) or sticking valves ( both sides ) or a loose manifold

 

[rhodesm]

Way too lean
So you either have a blown gasket ( both sides ) or sticking valves ( both sides ) or a loose manifold

Thank you. Do you know...is there anything like a Haynes or Chilton type manual for Kohler engines? I've done a head gasket on a car before using one of those manuals, but can't do it by heart. I did find a "service" manual for this engine, which goes through disassembly/inspection/reassembly. Read through it. It leaves a few things abiguous. But is there anything better anywhere? Thanks again.

 

[Rivets]

This should help you out. http://resources.kohler.com/power/k...16.1658754340.1601335970-986432130.1601335970

 

[rhodesm]

This should help you out. http://resources.kohler.com/power/k...16.1658754340.1601335970-986432130.1601335970

Thanks again!

 

[Oscar]

Hi, I have exactly the same symptom/problem. What was the eventual fix?