I have a 2000 maxima 3.0L engine 115k

On cold startup - talking about the temp outside is under 45 degrees
Something either under the car on the passenger side or by the firewall in the passenger side of the car rattles like crazy.

I don't know what could rattle inside the engine bay on that side beside the accesories belt and the Alternator belt. Can you think of anything? btw - I checked under the hood of the car none of them are wobbling.

My bet is the exhaust pipes running under the passenger side is loose and on cold startup it bangs on the body?

Once it warms up it goes away 100%...

Second Problem:

Ok, When ever I switch gears from P R or D there is a sqeeking sound. While holding on to the brake still.

This also occurs when I accelerate or when the car goes into 1-2 shift and there is a squeek.

I can duplicate the sound by revving the engine under the hood of the car ( forgot what that part is called next to the throttle body ) .

I also remember one time I was parking and I was turning the wheel all the way the squeek occurred also.

Anybody have any idea about the squeek? Worn Motor mounts?

 

I bet it's worn engine mounts.

 

+1 motor mounts. Try disconnecting them to see if the sound goes away.

 

Time to get out the stethoscope

Start the car early in the AM when it's cold. I bought a $10 stethoscope from an auto parts store. You could use a long handled screw driver.

When the problem is occurring, put one end on various parts of the car that could be suspect. Put your ear up to the other end. BE AWARE of the turning belts. Watch neighbors, watching you look like a dork

Within 2 minutes, you'll find exactly what is making the noise.

My bet is the timing chain, but I would have thought that was fixed on the 2000 3.0L engine. I had the same rattling noise on my 95 SE and the problem went away when the car warmed up.

Report back on your findings.

PeteMo.

 

It's easy to test if it is the motor mounts.
1. Start your car
2. With the brake applied, put it in gear
3. Slightly rev the engine while in both forward and reverse gear
4. With the hood open watch to see the engine rock drastically in either way or hit the firewall

If it does, it's probably a worn out rubber engine mount. I suggest replacing all of them together, cause the others are probably worn too. I just went through this a year ago. I could hear a banging sound since there was little to no rubber left when I reved it in gear with the brake applied.

 

One more thing. You mentioned it squeeked when it shifted and other times as we. Get some "Belt Dressing" and spray it on your power steering belt to test it for wear. It could be worn/dry if it's not loose and it could be overtightened to cause that sound. The spray is a cheap way to test if it is a belt or not. My theory is that if it stops when warm, it could be warming the dry belt making it more pliable and stopping the squeek. The $4 spray will tell you for sure.

 

i think its the engine mount too...

but the rattling on cold start up CANNOT be heard from the engine bay area ???

It is strongly heard by the glove box area...

I don't think its the timing chain...but I am not certain.

 

check your oil level.

 

if it was the timing chain and you can hear it in the cabin you would definitely be able to hear it in the engine bay. may be a vibration related to the potentially worn engine mounts. check those out and if need be change them then you can move on to the second problem.

 

oil level is fine - I check about every other week.

no leaks under the car either ( knock on wood )

I am deff looking into the mounts.

btw: any idea how much would it cost to be replaced parts+labor?

 

Mounts cost me $325 for both sides from Dave B with shipping. Labour cost was $160

Or you can get the ES bushings for less.

 

 

The ECM controlled front and rear mounts on this car that take the engine torque are not likely the issue here. There are exhaust parts like about three heatshields and the guts of two precats and the cat that may be causing the cold rattle. Get under the car when it's cold and shake or thump the exhaust and see if you can "simulate" the rattle. The "squeaking" sound that you hear may just be the IACV. If it's emminating from the TB and it's a "momentary" squeak or "chirp" sound when you move the gearshift from P to R or through N to D for example, or just when you start to accelerate, then it may be the IACV. The IACV also moves when moving the steering wheel at idle. Mine does it, but I have to have the window open or have the hood up to really hear it. If it's more of a squealing sound especially under rapid engine acceleration then check the condition and or the tension of your accessory drive belts. Old belts and/or low belt tension could cause such a squealing noise.

 

Yah, disconnect your motor mounts, see if it that works