90 sentra weird unknown noise need help please

[ahardb0dy]

Hello all, hope someone can help with this cause I have no idea where this noise is coming from !!

90 Nissan sentra, 212 K miles, originally had a 4 speed now has a new 5 speed transmission right out of the Nissan crate, 5 speed was installed at 183K 06-2007 using Amsoil gear lube, noticed noise yesterday on way home from work, I'll be driving along, speed doesn't matter although I haven't heard this noise when not driving, all of a sudden with no warning I started to hear this really loud noise, sounded like I was dragging something metal under the car, sounds like it's coming from the engine area and I also noticed when I hear the noise I can feel it thru the shifter. Got home from work and checked under the car with flashlight, exhaust looks normal, nothing hanging, checked under hood everything looks normal, nothing loose. This noise is quiet some times than other times it sounds really loud, thought oil was low so I checked it this morning on the way to work, it was a little low, topped it off but didn't help with noise. Have decent oil pressure on Autometer mechanical gauge, water temp is normal on Autometer mechanical gauge also. Checked oil level in transmission and it is full, timing chain and guides are original as far as I know, I bought the car with 117 K on it. Car runs great and when I hear this noise and can feel it thru the shifter it doesn't effect how it is running or driving. Could noise be from worn timing chain or guides?? mechanic said it may be the input bushing, checked my records and this was not replaced, he also said if I step on the clutch and the noise stops it most likely is the input bushing. Today when I got home with car in neutral it started making this noise almost sounds like nuts in the engine. Anyone ever have a noise like this any ideas on what it could be or what I should check?? Thanks all

[ABNRML4U]

Well I like to say Good Luck Man! Also Nice to see a Nico Florida member here.

[ahardb0dy]

thanks, I used to be on here a lot when we had our Infiniti Q45, lot's of questions with that complicated engine!! LOL

update on noise:

noise is getting more constant and now it is even making the noise when the car is not even moving, and also when the clutch is depressed!!, I have no idea what it could be

ANYONE???

[Faja]

could be the throw-out bearing on the clutch

[ahardb0dy]

the throw out bearing was new with the transmission, they came together, the transmission was new from a surplus place so no idea how long it was sitting. would the TO bearing cause noise whether the clutch was "in" or not??

[Faja]

If the car is in gear and you depress the clutch do you hear the noise? If so, then it could be the throw-out bearing. If you hear noise with the car in neutral and and clutch is not depressed could be transmission. Did you check fluid?

[ahardb0dy]

HAPPY THANKSGIVING

i hear the noise now even with car sitting still clutch in or out, checked fluid level in trans it was on level surface and when I took the plug out to check it the gear oil was coming out of the hole, so it may be just a little over full as I think you are supposed to be able to insert your finger in the hole and down to feel the fluid. Running Amsoil in the transmission

[Faja]

Yeah, your mechanic could be right - might be one of the transmission bushings or bearings.

[ahardb0dy]

checked out car today under hood, think noise is coming from either the alternator (which I got from junkyard out of a Maxima, I made a custom mount so I could mount the 110amp alternator), the A/C compressor (which is a rebuilt POS), or the idler pulley, going to remove the A/C belt tomorrow to see if the noise goes away.

[ahardb0dy]

removed the AC belt today, left the idler pulley on, took car for a drive, did not hear noise but did not drive that far, a good sign so far, after removing belt spun AC pulley by hand and it makes a noise at one spot like I can turn it 3/4 way around and it is quiet than in 1 spot I hear a noise. Don't think the idler pulley is causing noise going to leave belt off for a few days to see if noise is still present after longer drive, will update as I learn more, thanks all