knocking/vibration in the engine bay (5.5 gen Maxima)

[grey2k3]

Hey Guys,
I have a 2003 Maxima 5.5gen SE, AUTO

Within the past few months, my car has developed a mysterious knocking/vibration in the engine bay.

The problem occurs when the car is warm, is idling, and, when it’s in gear (Drive). As soon as I shift into neutral or park, the knocking/vibration goes away…but put it into gear, the problem comes back. Driving does not reproduce any symptoms. Only occurs when the car is in gear and at idle.

This has been an intermittent issue…but it’s happening more and more.
The knocking sounds like a quick “da da da da “ sound...

My accessories belt has recently changed….oil changed recently….no lights on the dash. Car has 140kms or 87k miles.

I will try to pin point where exactly is the sound is coming from…will probably get a friend to sit in the car while I'm outside listening…but before I do that…does anyone have an similar issue? anyone hear of this?

Any help will be appreciated.

Thanks!

[loystock]

Could be the engine mount but your best bet is to use a mechanics stethoscope or improvise with a long screwdriver to identify source of noise. Just don't touch moving components.

[Markc]

Also check for loose heat shields.

[NutriaforBreakfast]

With engine off spin the electric fans to see if they are hitting the shroud
and look for any contact/damage on those parts

I assume you are on level ground. You might try going up a parking ramp
to see if it makes the noise too