I have this problem fo rthe past 2 days.. not sure if I should worry about but. here it goes. it is a humming noise that is driving me crazy. Not sure of what it is, but the thing I know is that it happens in idle and acceleration. But funny, the normal noise that we have when we turn off the engine, which I cannot describe.. well when I shut the car off, the humming noise increases while we have that vacumm or whatever it is noise. Some help will be aprreciated.... hopefully I explained myself or at least someone understand. I know I dont....LOL

 

I get that sometimes too when i shut off the car it seems to come from the evap system in the back , i dont know what its doing but i hear it alot , also i got the humming up front but thats just my ac compressor.

 

While humming at idle put the transmission into N. You can atleast root cause it not to be coming from tranny.

 

I know now that it is not the tranny, I think is the AC compressor... but it also does the humming noise with the AC off, so it is on free wheel... Alternator? maybe....

 

I currently have the same noise. Test your alternator....

Turn of all accessories, listen to noise, then turn all on...does the pitch change?

Pull up facing a wall or garage door, turn on the headlights, rev the engine...lights get brighter?

Start the car, remove negative battery cable...car shut off? (if not make sure your turn off the ignition before you replace the negative cable so you dont short anything out)

Finally, get to autozone or similar and have them check the alternator...should be 14 or above.

I picked up a rebuilt 140A (stock is 110A) alternator off Ebay for $94 with a one year warranty. Now just have to decide if I'm gonna attempt the install myself or pay $100 labor

 

Check your radiator fans.

 

I also get a humm that starts at about 55 mph and it continues until about 70 mph and if I put the car in nuetral at those speeds the sound is still there until i get below 55mph. What could be causing this? Maybe my new flywheel is unbalanced?

 

Check your electronic motor mounts and quick. could blow your ECM

 

I have never heard of electronic motor mounts... What are they and what do they do? I know what a "motor mount" is lol but "electronic"??? How would I go about checking them? Is it possible i could have damaged the motor mount while doing my clutch?

 

Oh, you have stick? I dont think the manuals had the electronic mounts. Others on the forum may be able to verify that. But if you do you will see a set of wires coming out of the mounts. You can visually verify that.