I own a 2000 Accord EX sedan, 4 cylinder, A/T. I recently noticed that my engine makes a humming noise at idle. Similar to the noise that an A/C unit makes when engaged BUT my A/C is turned off when I hear this hum. Any help would be appreciated.

 

A noise over the internet is never fun......your hum is my whine.


All I can say from there is check the fluids - oil, ps, ect.

My guess, do not replace anything on a guess. The ps pump could be one of the many sources. Can you place a long screw driver on the pump - be safe ! - and then your ear on the handle....I know, sounds strange but a "poorman's" stethoscope.

 

I started my 2000 Accord and listened for the noise location. The humming seems to be coming from the engine component that's located on top at the back of the engine next to the firewall. This component has a hose connecting it to the engine air filter unit. Thanks again for any input.

 

You seen to be talking about the IAC valve, which regulates your idle. Is your idle stable?

 

Idle seems fine and the car seems to be operating fine. Only other complaint is that the temperature gauge moves up above the mid point shortly after warming up, then will settle in slightly below mid point thereafter. BTW, work done on the car within the last couple of weeks by Honda include radiator ( and hoses ) replacement and engine air filter replacement. Could the hum be caused by the replacement air filter ? Thanks for any input.

 

Location of the air filter doesn't match your location of the sound.

The IACV is bolted to the back side of the plenum of the intake manifold, back towards the firewall.

The thermostat is located below that; you could follow the lower radiator hose back to the T-stat.

Can you figure out if the sound is coming from higher (IACV) or lower (T-stat) location? Did they install a new thermostat?

 

It's hard to tell but it does sound like it could be the lower. BTW, the noise sounds like a vacuum cleaner.

 

Another kind of "poor-man's stethoscope" is a short scrap piece of garden hose held up to your ear. Just like the screwdriver version, make sure you don't get caught up in any spinning belts etc.

 

Pic....and then highlight the "said thing"?

 

chk he PCV valve make sure it is ok