Hello all,

I have noticed over the past year or so an odd noise emanating from the passenger side of my Evo IX that I can only describe as a sort of squishing and ticking noise. It sounds a lot like a fluid pump (maybe AC?). I can only hear it at idle (likely because my car is far too loud to hear otherwise). It is audible from within the car if there are no other noises and the radio is off. It is clearly audible from outside the car. I would say the noise is pretty consistent, warm or cold ambient, engine temp warm or cold, and it does not appear to have worsened over the year or so since I first noticed it. One other thing to note, it is reciprocating at roughly 1Hz, so it does not appear to be anything related to the engine itself, which leads me to believe its something to due with the clutched AC compressor or maybe something with coolant. I can't be sure, but I do not think high vs. normal idle effects the noise. I would like opinions and any experience with an odd noise like this. I want to make sure nothing is going to crop up and bite me because I have done nothing to alleviate this! Thanks!

- Nate

 

Mine was making some noise after my build. It was external engine so I let it go........ then my alternator took a poop. Hit it up with a mechanics stethascope (SP??)

 

My engine is totally stock, only mods have been forward of the intake manifold and after the turbo. It has been like this for quite a while as well and the alternator hasn't been giving me any issues.

I assume by external engine you mean it was not the original one? I unfortunately don't have a stethoscope and would have even less of an idea of how to use it... Any other ideas?

 

External meaning outside the engine. Something attached to it maybe.

Try a long screwdriver positioned on top of the alternator housing and then the handle end up to your ear. That way it's a cheap mans stethoscope. Good luck

 

Ok, I can try that. Any thoughts on what could be at 1Hz when the engine is idling at something between 10 and 20Hz? I think my high idle is about 1200rpm and typically warm idle is more like 800-900rpm. Thanks for your thoughts thus far!

 

The alternator brushes were making noise. It still worked for like 4 months after before it died. And yes, by external I mean not the internals making the noise, it was something connecting to the serpentine belt. If you're feeling crazy, pull the belt off and rotate all accessory components and feel for binding. Should take you about 20 minutes. And as far as HZ, I have no idea. Never measured my engine for sound frequencies. I know its a pain in the butt but its part of the diagnosing process. Kinda hard to tell not looking at the car. Good luck!

 

http://www.harborfreight.com/catalog...ne+stethoscope

As you can see, not an expensive tool. I have the one shown on the left and it works great.

How to use it? Put ear buds in ears and the other end on the engine. The only caution I would advise here is to hold the probe very lightly when working around moving belts as the belt might ****** the probe, pulling your hand into the belt.

You check around trying to locate where the noise you are concerned about is the loudest.

 

1 HZ would be the sound a battery operated wall clock makes - one tick per second.

 

I think it might be the small ticking noise that comes from mostly all IX's. It was a big deal back when the IX's were new, and it caused alot of commotion with owners. Many got their timing belts replaced only to have the noise come back shortly after. If it is the same noise that you are experiencing, then it is normal on IX's and as far as i know there is no fix.

Here is a short clip I found of the noise im speaking about.
http://youtu.be/KKPuqum1-xE

Why look what I found!! A sticky with 43 pages worth of that damn noise!
https://www.evolutionm.net/forums/ev...elt-video.html

 

That is not exactly identical but certainly close! I will keep an eye on the alternator for sure, but I think what you have there SmoothCTR is what I am experiencing.

Thank you all for the help! Much appreciated!

 

^ mine makes exactly same noise when cold starts and goes away after warms up. Sound comes back only in winter time.

 

Glad I can help. Hopefully that is the noise you are hearing, but still have someone listen to it like a shop familiar with evos just to verify.