I think tomorrow I am going to start digging around the floor area and sticking my head all around during warm up to see if I can pinpoint something. Update you guys tomorrow!

 

I've tried raising the car and starting it with a friend under it, but so far the nose hasn't happened when he has been under it. I will see if we can try again over the weekend and let you know. Also, since we have a video I'll be bugging a few people as well as my mechanic to see if they can give us a better idea of where the noise could be coming from.

PS not the tranny for sure because both automatics and manuals are doing it, and because the noise is there for me no matter what gear the car is in, P, R, N or D.

 

curious if anyone of you folks torque your belts. how do you do it in that tight space?

 

If you mean are they properly tensioned, yes. Its easy, there are bolts on each to adjust tension.

 

sorry, i mean the drive belt pulley. the 1st pulley that you need to loosen in order the change the belt.

 

If you are referring to the idler pulley, I don't understand how is that so difficult to adjust.... You are complaining about that and today I seen one of those old 94 Lexus in a shop (can't remember the model off the top of my head but the big body luxury ones that's long). My man was replacing the starter and you know where its located?? Comparing it to our VQ's, its where the knock sensor is...which means you have to take off the entire top half of the engine to change a damn starter with all your seals..

I mean come on...give the engineers credit where its due...The VQ is not difficult to work on at all...especially not adjusting the idler pulley you talking about. Now back to the topic at hand, any updates guys??

 

Not sure if this qualifies as a update but as it turns out my battery hasn't been holding a charge and its been slowly dieing everyday until today when I finally replaced that sucker.

And for the past two days I haven't heard anything during idle. But I am going to give it a few more days to see if its the temperature causing it to go away or if its really the battery.

 

Just listened to the Youtube clip. Damn. Here are some of my thoughts on it that may help you guys out.
1. It doesn't sound like a rotating assembly that corresponds to the engine's rpm (or anywhere near it). Meaning, the sound is way too fast.
2. Doesn't sound like an exhaust leak because there is no "pulse" to it.
3. Sounds "tinny", much like vibration through sheetmetal.

I would check for loose components and/or components that are missing the rubber mounting bushings (isolators). Especially ones mounted to sheetmetal, like the firewall, strut towers, under dash, etc.... Also, chek brackets on top of the engine.
To try to narrow it down, feel gently with your hands along everything (focusing on thinner metals) while the noise is present. If it is resonating sheetmetal, you can feel it, and may stop it with your fingers. Since it is reported on the driver's side, start on that side (to rule out normal engine vibrations, feel along corresponding passenger side to get the "rhythm" of normal vibrations).

@Leo, I doubt it is oil pump related. Going to a lighter weight oil, if it is oil related, will make it louder. People commonly thicken up their oil to get rid of oil related noises. Thin oils can be loud. I would definitely recommend you change to a 5w-30, though. I don't think Washington state gets warm enough to use a 40 wt in our cars. I live in Louisiana (100 + degree days common), and I wouldn't run a 40 wt in either of my VQ's. My UOA's (Used Oil Analysis) show Castrol GTX 5w30 is working perfectly. Having said that, VQ's do tend to like a thicker 30 wt (like GTX 5w30) over thinner 30 wts (like Syntec 5w30 or ~gasp~ Mobil 1 5w30. Mobil 1 is a fine oil for some engines, but UOA's of VQ's show it is not a very good match for the VQ). The best synthetic (which may benefit you in Washington winters) I've found for the VQ is known as German Castrol, or "GC". It's the Castrol Syntec 0w30 that is/was only available at Auto Zone, and says "Made in Germany" on the back label. Countless UOAs of it in VQ's show it's absolutely stellar performance. It may or may not still be available at Auto Zone. I used to run it, but I don't fully benefit from the synthetic oil because of my driving conditions (no really cold weather, and I religiously change oil at 3000 miles because I'm an old fart, and that's how we've always done it....) I currently use GTX 5w30 for my 3000 mile OCIs, backed up by annual UOAs. For all the info you'd ever want to know about engine oils (or any automotive lubrication and other automotive topics), check out the forums at: http://www.bobistheoilguy.com/forums...s.php?ubb=cfrm

Hope this helps.
Dave

 

Wow thank you Dave, that was the most educational advice I have ever received. And you are absolutely right I did a little Google-ing and found out that there were some complaints from Prius owners about engine noise and some people instead of using the recommended 5W-20 they used 5W-30 and it reduced engine noise drastically, and so that rules out my theory.

Also I have heard a ton about German Castrol and I was never really able to find any and so I saw that the Subaru guys religiously use the Shell Rotella T and also it has a lot of Zinc which helps the engine and so I gave it a go, strange thing was that I couldn't find it in 5W-30 only 5W-40 but thats probably because its made for diesels and heavy duty engines. And its served me well the engine itself is as quiet as ever but I am going to try German Castrol to see if it improves my engine even more haha

Also a little update, it seems like now as the whether is getting colder in Washington the noise is starting to go away, and during those few sunny hot days the noise comes back. And so I am going to try your idea and feel around for vibrations along the firewall because the noise sounds exactly like a traveling/resonating vibration that travels along metal. Anyways I will keep you guys posted!

 

It's not the oil. I am running GC and have been for a long time, and I have this drone too.

I am pretty sure the vibration is coming from poorly secured metal break lines on the firewall. They are metal and have these plastic spacers and clips that on my car have worn out over the past 300k.... I think those spacers, or rather the lack of their original placement and/or removal, or having been employed over their expected useful life etc., are causing the sheet metal like vibration as they rub against each other, especially because it is coming from the drivers side. Worth a look.

http://www.courtesyparts.com/maxima-...1879_1884.html

 

Oh darn it.

But DAAAAAMMMMMNNNNN this drone is like a invisible ghost that only comes out when you are not looking for it. Today I stuck my head everywhere I could along the firewall and I couldn't hear or feel any vibrations. There is this protective black paper material covering my firewall and I couldn't exactly feel the actually wall because of that cover. I think I will try and sneak in there to feel around.

 

WHOA, today while I was driving I all of a sudden heard the noise really really loud, it seems like it was 2x louder than the video. Then while I was rolling I heard it again and stepped on the gas harder to make it go away and then out of no-where a loud grinding noise started under the car. I stepped on the brakes and slowed down to like 2 MPH and it kept going for like a minute and then it all of a sudden stopped and I haven't heard it again. When that noise started I rolled down all my windows to see where it was coming from and it was too loud to tell it seems like it was all around the car.

And so when I got home today I popped the hood and looked around at the brakes and everything and nothing is missing or messed up. All my pulleys are there, brakes are normal, everything under the car looks normal.

 

Just a thought I haven't seen mentioned yet... Has anyone checked the crank pulley for play? Ours is a 2-piece unit with a rubber bushing between the pieces that sometimes goes bad. In my experience with rotating assemblies, things like this that wear out can cause an intermittent noise like you're describing. It would also explain why the consensus seems to be that the sound is better but not completely gone when the belts are removed. If the sound in that video is accurate, the crank pulley is the first thing I would check if this sound came out of my car.

The one thing that I'm not sure fits into this explanation is that the sound is being heard from the driver's side when I'm describing something on the passenger side of the engine compartment. I can imagine NVH being transmitted through the engine and mounts and into the floorboard, but it would be pretty weird to hear it from one end of that bracket and not the other.

Not sure if this will help, but i hope it does. Good luck, guys.

 

im noob to this site however i my mechanic and i have been in search of where this sound is coming from but like everyone else trying to diagnose we've had no luck. Has anyone had any issues with the belt squeek on start up?

 

I think I'm catching hints of this same/similar noise myself. I (think) it's a AC compressor bearing. The Noise seems to go away/get quieter with the AC off. I only notice The Noise on morning-starts though. I'm curious if it'll get louder or quieter as the weather continues to cool.

The only messed up part about my personal theory is: someone "eliminated" anything on the pulley-system by removed both of the drive-belts.

My only other half-assed educated guess would be either a heat-shield or an engine mount. . .

 

just a quick guess. it isnt any of your guy's heat shields for the b-pipe is it? Back in the day when I owned a honda they were notorious for having b-pipe heat shields that would rattle when idling, something about the right amount of vibrating when at idle. Try idling when the noise is present and have someone reach under and just hold the heat shield in a couple places. see if it stops. Hope it helps!

 

Nope, not the B-pipe. It's definitely coming from inside the engine bay.

Also, had a small breakthrough - today while the car was already nice and warm after 15 mins of driving, I was stuck at a long red light when the noise became loud enough to be easily audible. So I popped car into N and played with gas a little. I tried giving it a little bit of gas from ide (~700rpm) to about 1500 rpm. The noise did not change in pitch, consistency or even in the amount of vibration felt on the break pedal. That means the noise is NOT tied to the engine RPM. that just means at 1500+ rpm the engine just drowns out the noise or the vibration of the engine throws off the resonance of what ever part it might be.

In the past few days the noise has been very audible in my car and it looks like it is getting loud enough to hear even outside. So, tomorrow after work when the car is cold i'll see if I can listen around the engine bay figure out where it might be coming from.

 

Oh man, I almost forgot about this thread.

I have a strange new sound, while I was idling in a parking lot I heard a little squeaking sound, like a slipping belt while the engine is running. And so when I got home I popped the hood and revved the car by the throttle cable and heard nothing from the belts, it was then that I put my head towards the firewall where the brake booster was and I heard it, the squeak was coming from inside the firewall every-time I rev but inside the car you can hear it very clearly and loud.

It was also coming from the pedal area, I have a feeling there is something in the bottom vent or in the dash that vibrating/loose. But what could possibly be in the dash or in the vents that causes this? Unless its coming from under the car or actually INSIDE the firewall.

 

Leaking Seal in the Booster or fluttering check valve? That would make perfect sense, its under the dash and on the driver side, like we all thought, and wouldn't be RPM sensitive.

Disconnect the vacuum line and plug it. Run the engine in the driveway
while listening for noise.I'll try it later if no one else can.

 

Did anyone figure this noise thing out--I looked all over up and down in and out and i still cant find what causes that droning sound i also have a 97 Max 105K in excel condition looks and runs like the first day i bought it in 97...

While the droning noise can be heard clear in the drivers seat-I hear NOTHING when standing over the engine--nothing all i hear is the injector pulses--other then that the engine is quite as day one when i bought the car..


Its not an internal engine noise-not the ALT WP PS pump--its not an exh leak-Something under the dash--But cant pin point it!! My oil is always clean and fuil--i change it every 2,500 miles--and when i do change it it comes out golden brown..I also change the oil filter each time with nissan filters..

Does anyone to date have any ideas? Thanks all--have a great weekend..

 

Nope no ideas. For some reason the noise for me the noise has nearly disappeared. At least I haven't heard it or felt it strongly for a while now.

Funny enough, it stopped happening right after my last post so I still haven't been able to pin point it or figure out what could be causing it. =\

 

do u have a wideband... the car could be vibrating if ur car is running super lean... could be the egr clogged, or a bad o2 sensor... u wont throw a cel right away if this is the case

 

I suspect you haven't read through he whole thread. This doesn't affect the way the engine runs. The engine doesn't vibrate, shake, or misfire.
The best description of the symptoms is what you would experience from an electric motor with a hosed bearing, a high frequency-low pitch noise (growl or drone) accompanied by a high frequency vibration. This is too high frequency to be RPM related, and doesn't change pitch with increased RPM. Its only heard under the dash on the driver side, and is undetectable under the hood or car.

I give credit to Leo_Koneval for his latest post giving more clues.


I believe its vacuum related because it stops when I stab the throttle (low vacuum), and starts again after the throttle closes and engine decelerates (high vacuum). I suspect its in the brake booster because the booster acts like a bass drum and amplifies the condition. Could be a fluttering check valve or seal. I might get clever and put a ball valve in the line to turn it off when it start making noise.

 

Wow I can't believe I just gave all of us the biggest clue without knowing it!

Mine is getting worse, today was an especially cold day and when I started the car up for the first time it sounded almost like a piece of metal broke off and was getting spun around by a blender or something.

I think we finally got it, the brake booster makes perfect sense which is why we hear the noise and feel it in the driver's side only but no where else. Although, I don't know how we can fix this one besides replacing the whole thing. I don't remember how brake boosters work but could we possibly.... unplug the vacuum line to it and pour in some type of lubricant to see if it helps? I was thinking Seafoam or something similar, so that when the car starts it will just suck it out and clean the engine at the same time

 

Any petroleum based liquid will destroy the MC and booster rubber parts.
I have installed A ball valve in the vacuum line and will test next time the noise starts up.

 

I guess the only surefire way to know now is with your method, keep us updated!

 

Will do, I'm driving it to work tomorrow and thurs.

 

Started my car today as it was on an incline--Nose up--Didnt hear the sound at all--This morning i heard the sound pumped the break pedel a few times while the noise was there didnt make a difference--Infact--WENT under the hood--Unplugged the VAC line to the break booster--PLUGGED THE VAC LINE--RAN BACK INTO THE CAR--AND STILL HEARD THE DRONING NOISE--So its a strange thing--Today tho--while parked at work all day on an incline when i started the car i didnt hear the sound i did in the AM--its been cold out also.. S T R A N G E !!!!! Keep us posted if any one finds an answer............... MARK

 

I said it first biotches!

-much love

 

Oh damn!

 

Now that the weather is getting colder, that noise seems to be gone for the time being. I won't be interested in looking into it further until next year, especially after pawing around underneath while I did my oil change the other day :/

 

Its definitely vacuum related, I did the stab the throttle thing whenever I heard the sound and and every time I really stepped into it, the noise went away. And when I stepped lightly on the gas, like raise the RPM from 600 to about 1K the noise got louder, but if I went from 600 to about 3K-5K the noise goes away.

 

Well I closed the ball valve yesterday while it was making the noise, and it didn't make a difference. Ill look around for a vacuum reservoir or something else later.

 

Back to the drawing table?

I swear it is coming from somewhere inside the firewall. I wish there was a easy way to peek around without having to take the dash apart or doing some crazy thing in the engine bay.

 

I was sitting in my car before while it was cold-after about 2 minutes of running i started to hear the droning noise-Pissed me off this time--Look under the dash with a bright light--but didnt see anything Heard it tho near the firewall very clear However i opened the hood and use a stethoscope and i put it on the break booster--NO NOISE The second i put it on the Fuel filter which is mounted right on the fire wall i could hear the droning sound clear as a bell--and only in that fuel filter!!!!!! I found it and that doesnt explain why its making that noise......wild stuff indeed.......... hope this helps all of you with the same problem i have..Have a great night all.. Mark NY

 

Fuel Pump?? Regulator?? Filter?? Ok guys, has anyone changed one of these and noticed a change?

 

Come to think of it I have just changed my regulator and pump and I haven't heard it in awhile. Though the sound went away before I did all that...

I'll let you know if I hear it again. Now I know where to place the stethoscope (filter).

 

No way! Would a slightly clogged fuel filter restrict the flow enough to cause vibrations?

How is it mounted? Is it mounted to a bracket that is connected to the firewall?

Or maybe that sound is the sound of fuel flowing?

Anywho, I am going to dive into the filter tomorrow and see whats going on. There must be something we can do!

 

Another note!

I was messing around the front of the car a while back while it was at idle, and I stuck my ear near the air ram and heard some strange noises like a tiny vibration coming and going I assume it was the IACV or something. But it turned out my air filter which is white was covered with the white fuzzy tree seed stuff and I didn't know until I banged the filter on the ground and saw a bunch of stuff fall down.

So, before I saw that post about the fuel filter, I assumed the problem was vacuum related because of the kinda clogged air filter. But the search goes on.

 

Hello all--I'm back--To top the cake--when i unbolted the fuel filter from the firewall--I NO LONGER HEAR THE SOUND INSIDE THE CAR--but i do hear it when i listen to the filter with a scope.. WILD INDEED.. Whats really funny is--many of us hear this sound but it cant be a clogged filter--everyone has a clogged filter??? Mine is a few months old--and i hear the noise--ONLY WHEN ITS COOL TO COLD OUTSIDE (HAVNET HEARD IT IN THE SUMMER?

Very strange!!!!