G13B - 16V SOHC - Engine Noise question

[fixkick]

hi
may be vacuum leaks , they can whistle.
egr main diaphragm , crack can whistle. (behind #4 intake man tube)

ah forgot to say the rubber hose trick to one ear
move hose about find sounds, or sucking sounds, etc?

good luck, you seem on track.
cheers.

hello and greetings.
dropping belts was savvy !! way to go.
There are many sounds, possible. some are simple others not so.
It sounds like rod knock but i cant hear the double knock of it. a rod like to knock twice, as it changes direction bottom and top of cylinder.
mains like to know lugging and engine up hill.
it can be piston slap, that is not a big deal. (if not piston cracked cause)
use %5 stethoscope and listen all over engine. Everywhere, even engine mounts. take your time,...
http://www.fixkick.com/NOISE.html

1: the exhaust header end loves to fail.. if the doughnut gasket there, is bad , it sounds just like rods or mains bad. scary.!

SO I took my cave man stick or board and jammed it at header, and frame and reefed it over and bam, dead silent. (the cold chills ended )

2: then on the 97 the thing made this same class noise. found the rear mount on the huge aluminum MAIN AIR pipe mount broken, huge sounds. there.
this pipe ends up at the MAF. the head has a mount to it, that can fail at head mount or like mine broke the aluminum pipe tab mount. off, and even sucked air there
a double trouble failure.

that is my best idles here.
lots of places Noises can source. in and engine. IN ENGINE or anything connected to it. this engine shake it has no Silent shaft, tech,. off crank.

cheers.

I just created an engine sounds web page (LINK below) with 3 separate MP3 files on it. Please have a listen and let me know what your trained ear says!

Thanks for these reference links and suggestions. I did not really notice any regular knocking sounds, especially if you listen to the last sound clip: [the 14 second long post timing belt change] sound clip I posted. http://g13sohctom.wixsite.com/suzuki/sounds

[edit] I have a feeling the timing belt tensioner was responsible for a small contribution to noise, as the old bearing was a bit rough when I replaced it with a new one.

The currently most noticeable noise is a regular, deep wow-wow sound that seems to be at half crankshaft speed, as the noise seems to sync with ignition firing pulses. (I will try to observe a timing light pulse while listening to the sounds to confirm this).

If the engine is allowed to fully warm up to stable operating temperature, there is an occasional [teapot whistle] type sound (like a metal on metal high pitched squealing sound) that comes and goes. I did not run the engine very long with the water pump belt disconnected, but was able to confirm that the squealing sound happens without the water pump belt. This car (a JDM Swift) has a check engine light (CEL) but it is not currently illuminated.

My Plans:

(1) Buy a stethoscope today and try to listen all over to isolate the location of the noise.
(2) Should also perform a spark plug short test to try to isolate whether a specific cylinder is producing the noise.
(3) Drain and inspect the Mobil 1 oil that is currently in the car for any material. (as well as change the oil filter). This oil is the same oil in the car as when the noise was first noticed.
(4) This weekend I will try to take it for a short drive (with water pump belt reconnected of course) to see if the noise is present under load (lugging). I have never noticed it in the past, and I have pretty sensitive ears.
(5) I'll post a few engine bay pictures so that you can see whether you think I should check some other components.

Cheers
Tom