my 2004 monte carlo seems to idle fine in park, but when i shift into drive it begins to make a noise towards the front of the motor. Can hear it at stop lights. Sounds like something is vibrateing under the hood. I looked it looks like its either comeing from the top of the motor or the pullys pulling the drive belt. anyone helppp!!!!

 

any way you can take a video and share it?

 

not able to but do u have a guess whats going on

 

not really sure what can cause a 'vibration noise'...
Inspect your belt tensioner to make sure its not bouncing at idle & rev the throttle, or have someone press the gas pedal to see if it does the same thing.

 

Hi, I'm new to the forum, but have been an owner of an '04 monte carlo ss for four years.


I'm having the exact same symptoms that you described above and was wondering if you ever deduced what the cause was?


Or, if anyone else could shed some insight, I'd really appreciate it. I've been doing research on this for some time now and have found it hard to find anyone else who's had these symptoms with their car until now.


Thanks

 

check all of your mounts, the 2 dog bone mounts on top, the engine mount under the crank pulley, and the trans mount under the trans on the driver side.


i say this because there is not really a load on the the mounts in Park, but when you put it in drive, they are now under force.

 

really hard without being able to hear it...what kind of noise is it...screeching, knocking, whining?

 

Thanks, guys, I appreciate the responses.


In response to the question about the sound, it's tough to describe because it's more of a vibration. If I had to quantify it, I'd say it's more of a growl (definitely not a rod knock or valve tap).


I looked at all the mounts and they checked out ok. There was no cracking or separation of the rubber from the metal plates on either the lower engine mount or the transmission mount.


The vibration/sound is audible in Park, goes away in Neutral and is loudest in Drive and Reverse. I should also add that it is noisy in Park if I turn the wheels from left to right. This led me to suspect the power steering pump initially because it had been run dry on more than one occasion, but replacing it did not alleviate the symptoms.


I was thinking possibly the harmonic balancer. Have any of you experienced these kind of symptoms before with a bad HB?


I've been a DIY mechanic for over 10 years, so I'm hardly a newb, but this one really has me stumped. I've done a lot of research online about this and have found a fair amount of posts from people with similar symptoms, but no one seems to have a definitive answer on the cause.

 

Best thing to do is get a stethoscope...thats the best thing to do while its running...or use a screwdriver and put your ear to it...you should be able to track where it is coming from...the series one 3800 balancers had a lot of issues...not as much probs with the gen II and III

 

I already tried using a stethoscope to no avail. The noise was too difficult to track down that way.


Can anyone confirm if the lower engine mount on these cars can be worn out enough to cause noise/vibration without any visible signs of wear (cracking/separation of rubber)?