Yes, my 96 GXE is 5MT. We've ruled out tensioner, but not guides as far as I know. I have to drive mine 50 miles every day, but as soon as I can I'll remove the belts and run throughout a couple days. If someone else can do this, please do.

 

Austin I got your message and I have a automatic.

I noticed that my A/C was set of automatic and when I turned off the little AUTO light in the A/C the noise died down a lot even during the cold. Not sure if the noise and vibration was from my A/C trying to compress liquids and struggling or something.

But I have a giant A/C leak, and my A/C has been set to AUTO but I'm going to try to leave it off for a few days to see what happens.

 

I'm pulling my belts today. Got the AC/Alt belt off, still think I hear it real faintly, although some days it wont happen anyway. Gonna pull the PS now and give it a day and a half of starting and running in the driveway. Wish me luck, I hope its just an accessory and not the guides or oil pump.

 

I will mention this again - replacing your CAT should fix this issue - as it fixed it on mine - it will make a great difference in how your car runs as well.
I can also tell you it's not an 'accessory bearing' as I've had to drive for a ways with no belts on the car due to mine coming apart.
As for the oil pump - if it were this type of issue - your car would be trying to run hot (due to low oil pressure = hotter oil temps), as well it would cause a code and the oil light to flicker a lot (previous Nissan has a oil pump failure - it's a whole different sound than what your hearing/feeling).

 

I know the problem isn't related to me but what did you replace your CAT with? OEM, used, or aftermarket?

 

Hold your horses, if this was a catalytic converter issue, I think we should be able to hear the noise and vibration outside the car. But there is none.

And also if your catalytic has a clog or whatever then there would be a huge power loss and probably a check engine light or if the material was all broken inside I think we should be able to hear it clearly outside the car but the issue is that its only inside the car.

But in other news, I went with the lazy route and simply unhooked the power harness to the A/C to see what happens. And the noise has gone away, I can still faintly hear it when you first start the car for like a second but then its quiet the whole warm up through the drive. Which is strange, because the A/C should have been getting power anyway unless I turned on the A/C.... but at least its doing SOMETHING. Its been about 3 days of quiet idling with 1 really cold day. I'll keep you guys posted.

 

Good luck! I'm starting to suspect other things like the power steering as well

As for me the noise is still there but only partially like 10% of what it used to be. But I want it to be ZERO! GRRRRRRRRRRR!

 

Well, good news and bad news. Bad news is the noise is still there. Good news is the PS, AC, ALT, and belt tensioner are ruled out. I really don't think it is an exhaust problem, and I know it's not a heat shield. I'm still leaning toward TC-guides.
A video I made while doing this, doesn't really show anything useful.


http://www.youtube.com/watch?v=_LSesnLQSiw

 

Damn that did not sound like my car at all.

 

Actually you can't here the noise in that video.

 

I GOT THE SAME NOISE AND I CANT FIND IT WHERES ITS COMING FROM WHEN ITS COLD ITS MORE LOUDER WHEN ITS WORN THE NOICE IS GONE

 

FIXED

QUIT YELLING!! Were still trying to figure it out. I've got my issue narrowed down to internal engine.

 

Haha yeah that noise is like a ghost, you can't capture it on video or with a sound recorder only a person can hear it.

But guys this might sound crazy, but try cleaning your TB. I cleaned my TB and it rose my idle like 100 or 200 RPM, from the idle I set for it to save gas so now its back at stock idle but I can't hear the noise anymore. Also its been getting cold in Washington so its doing the opposite of what I suspected. There were little holes in the TB that I assume is for the IACV and they were gunked up, so I blasted cleaner into all those holes and started up my car in silence and then I realized.... no noise!

And also I messed around with the knock sensor as well, my harness was screwed and so I replaced it. I dunno if the retarded timing somehow caused a resonating vibration but yeah so far I have ruled out...

1.Cruise Control
2.A/C compressor
3.IACV
4.Transmission

 

Damn it fudge muffin cheese cake burrito. Never mind, the noise is still there except it is EVEN QUIETER than before. I think I am just going to give up and drive it as it is until something catastrophic happens.

 

Same here, I know its in the motor, and I cant afford to do anything about it. Ill build one later if I have too. Till then, I'll change oil every 3K and drive it like normal.

 

I really wish we could get to the bottom of it. I'm 100% certain we share the same problem. I was thinking some kind of intake leak on the brake booster line, but I'm tired of chasing it.

On to my interior.

 

Yeah its funny how we are all having the same problem. But no one can diagnose it... for me it can only be heard inside the car and its coming from the pedal/floor area. During warm-up and at idle and sometimes at low speed/RPM.

Raising my idle seems to do a little something but its only masking the vibrations with engine noise. But my idle was already a little low maybe like 500 RPM at operating temp. and in gear. But.................

I think you might be on to something, the brake booster. I mean its RIGHT on the firewall and if there was somehow a resonating vibration that were to come from there then it would be felt in the pedals and be heard in the car. Like maybe if there was a leak or something in there and it was engaging and disengaging rapidly that could possibly turn into a resonating vibration that travels along the firewall and to the inside of the car where we could hear and feel it in the floor and pedals.

 

I have been having a weird intermittent noise that I can not pin point either. I did find this clip on You Tube that you can hear it in. Let me know if its the same noise. I have it in the summer and the winter so I don't think its A\C related.

http://www.youtube.com/watch?v=hAFxR...eature=related

Recently I have changed out the exhaust Y Pipe to the tail, and it still makes the same noise. So I would have to rule out a exhaust leak.

Not throwing any codes right now, within the past month replaced all three O2s and knock sensor. Which were throwing codes.

 

Good lawd, that is a weird noise, subscribed.

 

Haha its not the brake booster... I tried stomping on the brakes right when I heard the noise and the noise just continued on happily for like 10 seconds.

Then I tried disconnecting the vacuum line to the booster and the engine ran funky but I could still hear it vibrating away...

Between the few of us, we have pretty much tried everything around the engine that could possibly cause a vibration. And I am now stumped, so now the only thing left to expect is the unexpected!

Maybe one of the pulleys are slightly moving up and down? Or maybe there is run-out in the flex-plate? I am so confused!!!

 

YES!!!!!!!!!!!!!!! GOD ALMIGHTY! Thats the noise, exactly tone for tone, note for note. Except mine isn't loud enough to capture on video. But the big question still remains what causes this?

 

Bingo, bud. That's the one. Really soft pur, but a gurgly hum.

Nice job. We got the ghost on the polaroid. I wonder if the brass will come to the rescue.

 

YOU NAILED IT!!! Thats the exact noise I'm hearing too. Droning like an electric motor with bad bearings with an abrupt STOP. then it starts again.

 

Any of you guys wanna just throw out ideas to see if we can exorcise this demon in our engines?

Also, I was fixing my fog lights with the engine on today and I noticed something odd. There is this really strange sound coming from my intake scoop. I used to have a ram air and I didn't hear it but after going back to stock I discovered an odd sound. Its not the normal vacuum sucking sound that you hear. There is an extra rumbling noise coming from inside the intake, I don't know if this has anything to do with our issue but its yet another strange sound.

 

I watched the video and was listenin to see if that noise gets louder when you give it gas..If yes or no, do this test for me...make sure you have a fully charged battery and remove the alternator belt completely and start the car. See if the noise is still there and post results. (If you can remove the power steering belt also, that would be helpful. If you do remove it, state so in your post)

 

I've already removed the belts, It doesnt help. Revving momentarily stops the noise.

 

Ok if you have done this, then this an internal engine problem. Try getting a compression test and post results.

 

I dont know if I'd say for sure it was internal, but I would definately be interested in hearing the verdict though. My 97 has started to have a similar occurance but only for a short time and at cold start.

 

same problem here...still workign on it

 

I don't know if its an internal engine problem. Like for example if it was a loose spark plug or maybe a spun bearing or whatever. We can hear it in the car AND we can hear it OUTSIDE the car.

Except in our cases we can ONLY hear it in the car or at least thats the case for me. And I even had someone sit in my car while I stand outside with the hood up and my ear like a foot away from the engine and during the whole time I didn't hear a thing except my car idling while my buddy hears the noises sitting inside.

Oh and one more thing, the vibration sometimes happen while revving up, and if I hold it at like a low RPM lets say 1k-2k then I can slightly hear it, the engine noise just drowns it out a bunch.

But either way I'm out of ideas, so might as well!

 

The noise comes and goes and I have noticed it over the past three years.Just to rule out certain things I will give you a list of all maintenance I have preformed since June.

June
Oil and oil filter changed
All six spark plugs changed
Front and rear brake pads

July
Y pipe, free flow cat and cat back installed

August
All 3 O2s replaced
Knock sensor replaced

 

Out of curiosity, what exaust system do you guys have? OEM, warpspeed, etc...(from headers to muffler)

 

I've got the same noise on the I30 but it does go away after the car's been running for 15-20 minutes. Doubt it's an internal drivetrain issue as I can't seem to hear it outside the car and it only occurs in a drive gear. Won't get a chance to get under the car again until the weather dries up.

 

I sadly have a stock exhaust system. But I've been looking at videos of people with broken bolts on their exhaust manifold and ect. And there is a noise that happens at a certain RPM but goes away when the engine is hot because the metal expands and all that.

But... but but but but but... I don't know what to think anymore. Nothing makes sense, unless the answer is right in front of us.

 

Don't give up man. That's why I would rather have you guys diagnose the problem so that I can better help you and make sure you are not wasting money. Well if you have a stock exhaust with a few studs broken here and there, that should be no reason for the noise..

Well from the two videos, is it safe to assume that its not tranny related because one was stick and one was auto?? If not, let me know.

EDIT: Also, I am thinking about the possibility of the oil pump causing that noise...can't find symptoms of one though. If asand1 is running without any belt, the noise is still present, and your exhaust is in good condition, the only other moving parts are inside the engine.

 

I've done a compression test recently, cylinder 1 -25% compared to the other cylinders... 195 as the baseline. I doubt it has to do with it. I've always thought it was the oil pump but I'm not going to fix something that isn't broken yet.

Sure would be nice to fix, though!

 

Why don't we all get together one morning (not physically) and call Car Talk until one of us gets through? :-)

 

I think the idea because the broken bolts is that there is a tiny gap where the exhaust seeps out and at each exhaust stroke it pushes against that gap and if you have a constant push, then no push, push, then no push, then I guess that could create a resonating vibration that travels along the car to inside the car. But once again i think it would be audible in the engine bay... unless the gap is so small that the engine noise drowns it out completely.

For the oil pump, at my next oil change I think I might try to use a lower weight oil like 5-30 instead of the 5-40 I am using to see what happens. But if it is the gears of the oil pump wouldn't we be able to hear it outside the car?

So the issue at hand happens:
1. Only when engine is cold
2. Audible only inside the car
3. Sound seems to be coming from floor area
4. Goes away at high RPM

But yeah lets keep brain storming, ONE of us has to figure this out eventually whether that be by mistake or hours of pondering.

 

Ok so if the sound only happens when its cold, have any of you gone under the car and have someone start it for you? You can listen to see if you hear the noise but if you don't, pass your hand over the exhaust pipe to feel for any air leaks... Maybe have the person rev a little also and maybe something may come up.

 

I also have had an auto and currently a stick. Both have made this noise when cold, and have the same 4 conditions that Leo has mentioned. I have been stumped and been trying to figure out this noise for a long time.