Strange new sound; ?? vacuum leak or fuel rail?? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

pony · 04-16-2017, 07:14 PM

Hope this is the right section, and feel silly asking, but can't hunt this down. I just installed headers and uploaded a custom tune on my Camaro that has been sitting for the winter. Upon starting, there is now a noticeable sound coming from the left front top engine area; near where a vacuum line that passes over the TB;enters the TB, and the fuel rail check cap. It sounds like a constant loud vacuum leak. This is also no where near the header exhaust/manifold that was done.

The car is running good, no codes, etc. and cannot "change" the sound by moving covering vacuum lines. Considered intake leak, but think it would be running worse, and nothing on this was touched.

ALSO, the engine cover was not installed, and maybe this is a fuel rail sound or other that has always been present, but masked by the cover. Looking for any ideas, or someone that has similar sound and/or can confirm this is normal. Most cars guys know how a "different" sound makes you paranoid. Thanks for any ideas/advice.

Ed805ls3 · 04-16-2017, 07:21 PM

Can you record the noise and maybe able to narrow down the sound?

pony · 04-16-2017, 07:58 PM

Quote:

Originally Posted by Ed805ls3

Can you record the noise and maybe able to narrow down the sound?

Sounds like a bad tire leak. Best I can get, but the "hissing" does go away slightly when the camera moves away from area.

ron123 · 04-16-2017, 08:00 PM

You can take a tube or section of heater hose and hold one end to your ear and move the other end around like a stethoscope; it should help you isolate where the sound is coming from.
Ron

15SSRS · 05-14-2017, 10:00 AM

After installing a catch can and starting the engine with the cover off I noticed the same sound in the same area. Engine runs good and no codes. Thinking it might just be a sound that was always present but muffled by the cover. With the cover on and hood closed it's not noticeable.

avido · 05-14-2017, 02:29 PM

Quote:

Originally Posted by pony

Sounds like a bad tire leak. Best I can get, but the "hissing" does go away slightly when the camera moves away from area.

try to spry directly a carburator cleaner and see if the idle speed drops.

InFiD3ViL · 05-14-2017, 03:51 PM

Double check all your vacuum lines again man. Especially near your PCV system. Whatever it is, its a big leak. Whats your normal idle RPM and what is your current idle with this sound?

I don't have any sounds like this, but I am also not running with a catch can.

*Just listened again on 100% volume. Damn, sounds like a lot of air. Surprised you're not having other issues or throwing a code.

QUICRNU · 05-14-2017, 09:27 PM

I would consider removing those vacuum lines for inspection. I had a cracked plastic line (the 1st one you wiggled) on mine. I couldn't change the sound by wiggling, but when I took it off it was clearly the issue. You can replace those with a pliable vacuum hose. I am also running a Catch Can and mine does not make this sound.

15SSRS · 05-15-2017, 01:59 PM

I'm not the OP and don't mean to hijack, but my car makes the exact same sound. I was expecting to hear that it's normal since there is no code and it idles fine and steady at 5k rpms. I'll try the carb cleaner trick when I get home for good measure.

QUICRNU · 05-15-2017, 06:24 PM

Be careful not to knock debris loose to be sucked in. Just spray smart

pony · 05-15-2017, 06:39 PM

Quote:

Originally Posted by 15SSRS

I'm not the OP and don't mean to hijack, but my car makes the exact same sound. I was expecting to hear that it's normal since there is no code and it idles fine and steady at 5k rpms. I'll try the carb cleaner trick when I get home for good measure.

.
Not a problem at all. All here for help and answers. Mine continues to run just fine. When I do pull a vac line, it goes to shit. May also try the carb clean to see what happens. Dyno Steve thought it was just air flow and with no codes or idle issues, it was probably just fine. If anything changes, will update post.

04-16-2017, 07:14 PM	#1
pony Drives: 2011 2SS Convert; Color RJT Join Date: Sep 2009 Location: Nebraska Posts: 722	Strange new sound; ?? vacuum leak or fuel rail?? Hope this is the right section, and feel silly asking, but can't hunt this down. I just installed headers and uploaded a custom tune on my Camaro that has been sitting for the winter. Upon starting, there is now a noticeable sound coming from the left front top engine area; near where a vacuum line that passes over the TB;enters the TB, and the fuel rail check cap. It sounds like a constant loud vacuum leak. This is also no where near the header exhaust/manifold that was done. The car is running good, no codes, etc. and cannot "change" the sound by moving covering vacuum lines. Considered intake leak, but think it would be running worse, and nothing on this was touched. ALSO, the engine cover was not installed, and maybe this is a fuel rail sound or other that has always been present, but masked by the cover. Looking for any ideas, or someone that has similar sound and/or can confirm this is normal. Most cars guys know how a "different" sound makes you paranoid. Thanks for any ideas/advice.

04-16-2017, 07:21 PM	#2
Ed805ls3 Drives: 2010 Camaro LS3 SS Join Date: Jun 2016 Location: Oxnard Posts: 62 View My Garage	Can you record the noise and maybe able to narrow down the sound? __________________ Maggie heartbeat SC, 3.40 Pulley, ZL1 FP, ADM FPCM, ZR1 3 bar map sensor, ID1050x injectors, Rotofab CAÍ, BBK Long tube headers, BBK HF cats, axle back loudmouth exhaust. McLeod RST Twin Disk Clutch, Tuned by Ted Jannetty, Tires: Nitto NT555R

04-16-2017, 08:00 PM	#4
ron123 Drives: 2014 2SS/RS Join Date: Dec 2014 Location: Raleigh, NC Posts: 1,053	You can take a tube or section of heater hose and hold one end to your ear and move the other end around like a stethoscope; it should help you isolate where the sound is coming from. Ron __________________ 2014 2SS/RS, Z28 CAI and High Wing Spoiler, ZL1 5.1:1 Ratio Short-Throw Shifter, ZL1 Pedals, ZL1 splash guards, NPP Dual-mode quad tip exhaust, Z28 strut tower brace, Camaro LED Cup-holders with footwell Lighting option, Leather visors, and Leather E-brake boot. Chevy dealer sponsored 67 retro SS nose stripe package.

05-14-2017, 03:51 PM	#7
InFiD3ViL Drives: 2010 CGM 2SS/RS LS3 Swapped A6 Join Date: Sep 2016 Location: Spring Hill, FL Posts: 4,575	Double check all your vacuum lines again man. Especially near your PCV system. Whatever it is, its a big leak. Whats your normal idle RPM and what is your current idle with this sound? I don't have any sounds like this, but I am also not running with a catch can. Just listened again on 100% volume. Damn, sounds like a lot of air. Surprised you're not having other issues or throwing a code. __________________ 2010 CGM Camaro 2SS LS3 Swapped A6 - GPI LS3 SS1 .647/.638, (224/237, 112 +4, 7º overlap) on CamMotion 8620 core, BTR Platinum .660" Dual Spring kit w/titanium retainers, CHE bronze trunnion upgrade, stock heads milled @ .015, Melling HV 10296 oil pump, TSP 1-7/8" long tube headers (W/Catless Off-road Pipes), Corsa Xtreme 3" Catback, GPI Ported/Rod Mod Intake, Stage 2 Ported Throttle Body, Vararam OTR CAI, Mike Norris Gen 2 catch can + GM 1LE clean side separator, 160º thermostat - Megan Racing adjustable coilovers (lowered 1.75"), MRR M017 10/11" wheels-Tuned by Ryan @ GPI Last edited by InFiD3ViL; 05-14-2017 at 04:05 PM.*

05-14-2017, 09:27 PM	#8
QUICRNU Drives: Z06 wannabe Join Date: Feb 2015 Location: Daytona Beach, FL Posts: 1,200	I would consider removing those vacuum lines for inspection. I had a cracked plastic line (the 1st one you wiggled) on mine. I couldn't change the sound by wiggling, but when I took it off it was clearly the issue. You can replace those with a pliable vacuum hose. I am also running a Catch Can and mine does not make this sound. __________________ Apex Focused

05-14-2017, 10:00 AM	#5
15SSRS Drives: 2015 2SS RS Convertible Join Date: Apr 2017 Location: Michigan Posts: 23	After installing a catch can and starting the engine with the cover off I noticed the same sound in the same area. Engine runs good and no codes. Thinking it might just be a sound that was always present but muffled by the cover. With the cover on and hood closed it's not noticeable.

05-15-2017, 01:59 PM	#9
15SSRS Drives: 2015 2SS RS Convertible Join Date: Apr 2017 Location: Michigan Posts: 23	I'm not the OP and don't mean to hijack, but my car makes the exact same sound. I was expecting to hear that it's normal since there is no code and it idles fine and steady at 5k rpms. I'll try the carb cleaner trick when I get home for good measure.

05-15-2017, 06:24 PM	#10
QUICRNU Drives: Z06 wannabe Join Date: Feb 2015 Location: Daytona Beach, FL Posts: 1,200	Be careful not to knock debris loose to be sucked in. Just spray smart __________________ Apex Focused