Quadrajet making a whistling noise - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Reziel_1983 · 02-09-2011, 06:08 PM

Okay, so lemme explain what is happening.

I used to have an edelbrock 600 cfm carburetor on my 350. The 350 had headers, and edelbrock performer intake and a cam that was 3 steps above stock(I think).

We installed a bigger cam because my cam had a bad lobe and lifter so we just decided to upgrade to a bigger cam. With this new cam in and the edelbrock 600 cfm still on the engine we couldn't get the timing to be set. We could never get it to stop clattering, so we decided to try to put the old quadrajet back on. T

he timing on the engine is now set correctly but the carburetor is now making a whistling noise. We have had the quadrajet rebuilt before putting it back on. I'm a little new to engines and was wondering if anyone knows what might be wrong.

Thanks

jchav62 · 02-09-2011, 06:23 PM

Sounds like a vacuum leak to me. Check to see if there are any loose vac. lines or possibly an unused vac. port. Also, check if there is a good seal at the carb. base. Did you use a new base gasket?

Reziel_1983 · 02-09-2011, 06:46 PM

Quote:

Originally Posted by jchav62

Sounds like a vacuum leak to me. Check to see if there are any loose vac. lines or possibly an unused vac. port. Also, check if there is a good seal at the carb. base. Did you use a new base gasket?

Vac. lines are good I'm pretty sure... I'll recheck them once it warms up. I think we are going to get a new base gasket because we didn't get a new one, hopefully that'll fix it, thanks.

Restrorob · 02-09-2011, 06:54 PM

Also check the primary and secondary throttle shafts for wear/play in the base, They can cause a whistle as well.

JMac11 · 02-09-2011, 07:33 PM

Make sure the choke is firmly seated to the throttle body.

sierra4x4 · 02-09-2011, 11:03 PM

One time I had a whistle and it turned out to be where my air cleaner meets the carb. My air cleaner was hanging up on something and wasn`t fully seated on the carb.

jitteryguy · 02-10-2011, 12:13 AM

look close at all the mount'n tabs on the carb when ya replace the gasket, I've seen em crack there and leak vacum (whistle) . if it is crack'd the Edlebrock 600 will run with that cam, it just may need a good clean'n.

Malo83 · 02-10-2011, 03:40 PM

Spray carb cleaner around the base of the carb and vac lines if the RPM changes when you spray an area, that is where your vac leak is

Reziel_1983 · 02-10-2011, 11:13 PM

Thanks for the suggestions guys, I'll check all these on Saturday.

02-09-2011, 06:08 PM	#1
Reziel_1983 Registered User Join Date: Feb 2011 Location: Brownwood, Texas Posts: 421	Quadrajet making a whistling noise Okay, so lemme explain what is happening. I used to have an edelbrock 600 cfm carburetor on my 350. The 350 had headers, and edelbrock performer intake and a cam that was 3 steps above stock(I think). We installed a bigger cam because my cam had a bad lobe and lifter so we just decided to upgrade to a bigger cam. With this new cam in and the edelbrock 600 cfm still on the engine we couldn't get the timing to be set. We could never get it to stop clattering, so we decided to try to put the old quadrajet back on. T he timing on the engine is now set correctly but the carburetor is now making a whistling noise. We have had the quadrajet rebuilt before putting it back on. I'm a little new to engines and was wondering if anyone knows what might be wrong. Thanks __________________ 1983 Chevy lwb: 400 sbc destroked to 377, comp cams xe 268, Holley Street Dominator Intake, Holley Street Avenger 670 cfm, headers, flowmasters. SOLD 1998 Trans am, mostly stock with magnaflow catback My build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=454329

02-09-2011, 06:23 PM	#2
jchav62 1962 C-10 Join Date: Apr 2005 Location: Las Vegas, New Mexico Posts: 4,978	Re: Quadrajet making a whistling noise Sounds like a vacuum leak to me. Check to see if there are any loose vac. lines or possibly an unused vac. port. Also, check if there is a good seal at the carb. base. Did you use a new base gasket? __________________ Joseph Chavez "See the USA in a Chevrolet!!" ......................_____ .........________//__{\_____ ,,,,,,,/__(O)___//___/__(O)_/ 1962 C10 Shortbed Fleetside 327/th350 GV overdrive 1974 C10 Longbed Fleetside 350/th350 "The Trash Truck" 1999 Chevy 2500 OBS, Longbed 5.7/4L80E 4x4 2015 GMC Sierra SLE 1500 4x4 Last edited by jchav62; 02-09-2011 at 06:23 PM.

02-09-2011, 06:54 PM	#4
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: Quadrajet making a whistling noise Also check the primary and secondary throttle shafts for wear/play in the base, They can cause a whistle as well. __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!* Last edited by Restrorob; 02-09-2011 at 06:56 PM.

02-09-2011, 07:33 PM	#5
JMac11 Registered User Join Date: May 2005 Location: Tallahassee Fl Posts: 773	Re: Quadrajet making a whistling noise Make sure the choke is firmly seated to the throttle body.

02-09-2011, 11:03 PM	#6
sierra4x4 Registered User Join Date: Jan 2009 Location: Canada Posts: 308	Re: Quadrajet making a whistling noise One time I had a whistle and it turned out to be where my air cleaner meets the carb. My air cleaner was hanging up on something and wasn`t fully seated on the carb.

02-10-2011, 12:13 AM	#7
jitteryguy GoatLube Experss Join Date: Oct 2009 Location: clarksville, Tn. Posts: 1,337	Re: Quadrajet making a whistling noise look close at all the mount'n tabs on the carb when ya replace the gasket, I've seen em crack there and leak vacum (whistle) . if it is crack'd the Edlebrock 600 will run with that cam, it just may need a good clean'n. __________________ *Goat Lube Express*, locations in Qalat,Afghanistan & Clarksville, Tn. '87 R30 dually 454/TH400 '85 1/2 ton CCSB '92 S10 350/350 '84 MonteCarlo 383/PG/9"ford '78 Malibu wagon 350/350 '78 Cutlass (project family car) '96 S10 Jimmy (Moma's)

02-10-2011, 03:40 PM	#8
Malo83 Cruzzzn' Vet Join Date: Jan 2005 Location: Porterville,Ca. Posts: 1,918	Re: Quadrajet making a whistling noise Spray carb cleaner around the base of the carb and vac lines if the RPM changes when you spray an area, that is where your vac leak is

02-10-2011, 11:13 PM	#9
Reziel_1983 Registered User Join Date: Feb 2011 Location: Brownwood, Texas Posts: 421	Re: Quadrajet making a whistling noise Thanks for the suggestions guys, I'll check all these on Saturday. __________________ 1983 Chevy lwb: 400 sbc destroked to 377, comp cams xe 268, Holley Street Dominator Intake, Holley Street Avenger 670 cfm, headers, flowmasters. SOLD 1998 Trans am, mostly stock with magnaflow catback My build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=454329



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