Screeching noise.... HELP

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May 31, 2007 | 09:04 PM

Superman09

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From: MI

Screeching noise.... HELP

Ok, well last night i got my car all set for the dyno (taking it on Tues) I got my exhaust all clamped back up and a bung welded into my exhaust for the wideband to tune. I also installed a check valve in my feed line right at the turbo to prevent the oil from the lines draining into the lower turbo when i shut the car off. Sooo i fired the car up last night and sure enough the turbos were getting oil, GOOD. Tonight i hop in my car to take a drive and i checked and they were still draining (clear line) and i go to leave and as i give it gas like 1k (idles at like 500) and there is a screech i've never heard before, so i immediately put the car in reverse and back into the garage. I swapped out restictor to see if maybe it wasnt getting enough oil and i just resorted to NO restrictor to test it and it still make the noise! Its a simple screech when i give it some gas (quiet at idle). I have no idea what the issue is. I even took the lines off and they are definitely getting oil for sure. I also took off my air filters and checked the compressor wheels, no play in either and they both spin just fine? Any ideas......? please help, any input is appreciate, i want to drive my car into a river!

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May 31, 2007 | 09:14 PM

MIGHTYMOUSE

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get someone to verify where said 'screech' is comming from, go from there

May 31, 2007 | 09:20 PM

Superman09

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From: MI

how do i do this? I dont want to drive the car anywhere, i'm nervous its something major so i dont want to drive it AT ALL, any ideas what might make a screech noise sort of like nails on a chalkboard?

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May 31, 2007 | 09:30 PM

code4

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Quote:

Originally Posted by Superman09

Just start eliminating one thing at a time. Can you recreate the sound in neutral or in gear without moving? If so then it's in the engine, you might try taking the serpentine belt off and try it again while the engine is cold. If it's still there I would look at flywheel? Balancer rubbing something.

I doubt it would be the turbo's they would make the same noise from 500 rpms to 1k.

May 31, 2007 | 09:32 PM

Superman09

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From: MI

car DOESNT need to be in gear, i just threw some revs from the TB up to 1k and it made the noise, so its engine. Only thing i've changed since i last drove the car was the check valve.... but they are still getting oil?

So my turbos would make the screech noise right from 500 if they were the issue?

Thanks, really appreciate it!

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May 31, 2007 | 11:12 PM

02NBMFormula

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From: Jax, Fl

if you can recreate the noise at idle, grab a long handled screwdriver and place the tip on various parts and put your ear to the handle of the screwdriver to listen for it. use process of elimination to narrow it down. yeah its a strange thing to do but it works.

Jun 1, 2007 | 05:48 AM

cablebandit

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From: Cleveland, OH

i got that once with no pcv valve but full vacuum to the crankcase...i think it was pulling the oil off something. Make SURE oil is getting to that turbo....i told you how my checkvalve went...coulda changed...not likely but make SURE you got oil to turbo

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Jun 1, 2007 | 09:26 AM

cablebandit

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From: Cleveland, OH

you are running an actual pcv valve correct?

Jun 1, 2007 | 09:31 AM

#10

Superman09

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ok, just went out and its making the noise still this morning, they are definitely getting oil, at least half of the -10an line is full when they are draining and just slight revs gives the screech, i made a vid and am uploading it now so you guys can hear the noise and maybe recognize it as to what it may be? Thanks!

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Jun 1, 2007 | 09:32 AM

#11

Superman09

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my pcv is just totally vented, there is nocheck valve in it anymore....

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Jun 1, 2007 | 09:44 AM

#12

Superman09

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From: MI

Okay, here is the vid (works now) http://video.ls1tech.com/video/23617...4000b19304.htm
The first loud *** noise before i start the car is my scavenge pump, then i decide to show the oil draining but need to grab a flashlight, haha. Then you can see it draining in the clear line, then at the end i give it a little gas and you can hear the trecherous noise! AHHHHHH

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Last edited by Superman09; Jun 1, 2007 at 09:50 AM.

Jun 1, 2007 | 10:00 AM

#13

TS6

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Take the belt off and run it.

Could just be a bad tensioner bearing or water pump. Heat from the turbos can wreak havoc on **** sometimes.

Jun 1, 2007 | 10:06 AM

#14

Superman09

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PWEEEEFFF, thanks a lot guys, just fired the car with no belt and no noise! Gave it a few revs and nothing and brought it up to prolly like 1,500-2k ish and nothing but a hint of turbo whistle

So now i need to figure out what in my belt line is screeching like a ****! Thanks again, i was REALLLLLLLLY nervous!

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Jun 1, 2007 | 10:31 AM

#15

cablebandit

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no ****...nobody likes screeching. My ac belt squealed bigtime....just got a new one. If your alternator is relocated, see if its hitting the thermostat housing

Jun 1, 2007 | 10:33 AM

#16

cablebandit

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just heard the vid...i swear that sounding like mine when i had full vaccum applied to the crankcase/valvecovers with no pcv valve.

Jun 1, 2007 | 10:39 AM

#17

Superman09

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hmm, wouldnt it still make that noise if that were the issue with no belt on? I did just swap over to that chromed alternator with a smaller stock pulley so i'm guessing something there isnt lined up right or the alternator is squeeking/belt rubbing somewhere. Thanks for the help! More trouble-shooting tonight after i get back from my golf tourney!

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Jun 1, 2007 | 11:32 AM

#18

TS6

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I'm gonna stick with the belt tensioner. Either that or the smaller pulley on the alternator has caused some contact somewhere. Could also just be the belt.

Jun 1, 2007 | 12:00 PM

#19

MIGHTYMOUSE

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i was gonna say, if you give the crankcase full engine vaccum you will suck air in past the main seals, i had that noise once, kurt set me straight.

Jun 1, 2007 | 05:38 PM

#20

Superman09

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I think its the pulley on the new alt, im going to lounge around for a while and go troubleshoot later tonight. Thanks for the help everyone, that scared the be-jitters out of me, hahaha.

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