Strange noise - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dion · 05-30-2002, 11:40 PM

I noticed a weird noise comming from the t converter, it sounds like somthing is loose like a rattle but everything looks good under there. New flex plate and the tranny seems fine, no problems driving. My kick down cable does need ajusting, that much I do know. Any ideas?

*Zkast* · 05-31-2002, 12:04 AM

Strange question but do you have headers? Just last week I was chasing a wierd noise on mine... turns out it was a header gasket that would flutter at times. Didnt have the tradition pop pop pop sounds. It sounded almost metalic... large metalic lol

Just an idea

Does it change from hot to cold? Or when you put it into gear vs neutral? Give us a few more details on when it happens, what you can/cant do to change the pitch of the noise or make it stop all together.

dion · 05-31-2002, 01:09 AM

Yes I have headers. The noise is definately comming from the tranny area. It does seem to be loudest when hot.

Big69C20 Toy · 05-31-2002, 01:13 AM

I have that same dang noise, i was thinking it was a rocker i needed to adjust but when i got under the truck with it running it sounds like it's right at the very back of the engine or about that area where the converter is and stuff. It does it all the time but like he says most prodominent when hot, just sounds like something tapping, like i said sorta thought a rocker arm but not from that area and more of a solid tap sound.

Thanks from me too!

**68 Stepside** · 05-31-2002, 01:15 AM

My Z28's tranny was going kaput when I got rid of it...and it'd make a lifter-type tapping noise in the trans, b/c the front pump was going bad. Just an idea.

TJ

ebfabman · 05-31-2002, 01:24 AM

This might be a stupid question but have you guys check to see if the bolts that go through the flexplate(flywheel)to the torque converter are tight?

Big69C20 Toy · 05-31-2002, 01:26 AM

good suggestion! i thougth about that but coulndt really tell too much and how can i crank the engine by hand? that BB is heavy! hehe

*Zkast* · 05-31-2002, 01:40 AM

I'd use a remote start or have someone bump the starter over. Unplug your distibutor hot wire first though. Look for a lite rust color around the flexplate while you checking the bolts... if you have a cracked flexplate it will start to produce rust colored metal dust.

Does it go away when put in gear? does it seem to correspond with engine rpm? Is it a very timed tapping noise or is it someone irratic?
Sorry for all the questions but there are just too many things thats could cause such a noise.

I'd rule out a cracked flexplate, depending on how you answer the above... there could be a starter bendix problem ( drive extending on its own), front pump as noted before, carbon buildup on the piston (rear cylinders).

Big69C20 Toy · 05-31-2002, 02:00 AM

it seems to go away with higher rpm but that could be just cuz of the drowning out by the motor. it's most noticeable at idle cuz you hear this light tapping, very stable always there and yeah it does speed up a li'l when i go a slight bit above idle. I'll check those bolts tommorow or this weekend.

dion · 05-31-2002, 10:24 PM

Bolts are good, flywheel is new. I starts when it's hot and it does seem to go with the idle. Converter? Tranny?

*Zkast* · 05-31-2002, 10:46 PM

At work I use a cheap pair of automotive stethiscopes availible from Napa (lisle makes them) This will allow you to pinpoint the exact area of the noise. If its definatly coming from the transmission and the flywheel bolts are tight.. there is little you can do at this point. See if you can pinpoint where the exact area of the noise is though.

Sorry I cant be of more help... Hard to diagnose via TEXT lol

Wasted Income · 06-01-2002, 02:47 AM

I may have a possible soulution. My buddy had the same (lifter) type noise coming from his '87. Come to find out that when they re-installed the tranny, they pinched a grounding strap between the bellhousing and motor, and it was flicking off of the flexplate. VERY simple solution. Hopefully that's your problem!!!

Big69C20 Toy · 06-01-2002, 03:52 AM

Mine was a flexplate bolt, simple fix. thanks guys,

*Zkast* · 06-01-2002, 10:12 AM

Whew! One down........ One to go

05-30-2002, 11:40 PM	#1
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	Strange noise I noticed a weird noise comming from the t converter, it sounds like somthing is loose like a rattle but everything looks good under there. New flex plate and the tranny seems fine, no problems driving. My kick down cable does need ajusting, that much I do know. Any ideas? __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

05-31-2002, 01:09 AM	#3
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	Yes I have headers. The noise is definately comming from the tranny area. It does seem to be loudest when hot. __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

05-31-2002, 01:13 AM	#4
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	glad i'm not crazy I have that same dang noise, i was thinking it was a rocker i needed to adjust but when i got under the truck with it running it sounds like it's right at the very back of the engine or about that area where the converter is and stuff. It does it all the time but like he says most prodominent when hot, just sounds like something tapping, like i said sorta thought a rocker arm but not from that area and more of a solid tap sound. Thanks from me too! __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

05-31-2002, 01:15 AM	#5
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,690	My Z28's tranny was going kaput when I got rid of it...and it'd make a lifter-type tapping noise in the trans, b/c the front pump was going bad. Just an idea. TJ __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

05-31-2002, 01:26 AM	#7
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	good suggestion! i thougth about that but coulndt really tell too much and how can i crank the engine by hand? that BB is heavy! hehe __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

05-31-2002, 12:04 AM	#2
Zkast Account Suspended Join Date: May 2002 Location: Olathe, Kansas Posts: 929	Strange question but do you have headers? Just last week I was chasing a wierd noise on mine... turns out it was a header gasket that would flutter at times. Didnt have the tradition pop pop pop sounds. It sounded almost metalic... large metalic lol Just an idea Does it change from hot to cold? Or when you put it into gear vs neutral? Give us a few more details on when it happens, what you can/cant do to change the pitch of the noise or make it stop all together.

05-31-2002, 01:24 AM	#6
ebfabman Registered User Join Date: Nov 2001 Location: Concord, NC Posts: 2,488	This might be a stupid question but have you guys check to see if the bolts that go through the flexplate(flywheel)to the torque converter are tight?

05-31-2002, 01:40 AM	#8
Zkast Account Suspended Join Date: May 2002 Location: Olathe, Kansas Posts: 929	I'd use a remote start or have someone bump the starter over. Unplug your distibutor hot wire first though. Look for a lite rust color around the flexplate while you checking the bolts... if you have a cracked flexplate it will start to produce rust colored metal dust. Does it go away when put in gear? does it seem to correspond with engine rpm? Is it a very timed tapping noise or is it someone irratic? Sorry for all the questions but there are just too many things thats could cause such a noise. I'd rule out a cracked flexplate, depending on how you answer the above... there could be a starter bendix problem ( drive extending on its own), front pump as noted before, carbon buildup on the piston (rear cylinders).

05-31-2002, 02:00 AM	#9
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	it seems to go away with higher rpm but that could be just cuz of the drowning out by the motor. it's most noticeable at idle cuz you hear this light tapping, very stable always there and yeah it does speed up a li'l when i go a slight bit above idle. I'll check those bolts tommorow or this weekend. __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

05-31-2002, 10:24 PM	#10
dion 72 Cheyenne Join Date: Oct 2001 Location: San Diego Posts: 2,086	Bolts are good, flywheel is new. I starts when it's hot and it does seem to go with the idle. Converter? Tranny? __________________ Burnout Idle 1972Cheyenne 1966/67Stouts

05-31-2002, 10:46 PM	#11
Zkast Account Suspended Join Date: May 2002 Location: Olathe, Kansas Posts: 929	At work I use a cheap pair of automotive stethiscopes availible from Napa (lisle makes them) This will allow you to pinpoint the exact area of the noise. If its definatly coming from the transmission and the flywheel bolts are tight.. there is little you can do at this point. See if you can pinpoint where the exact area of the noise is though. Sorry I cant be of more help... Hard to diagnose via TEXT lol

06-01-2002, 02:47 AM	#12
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	Possible solution I may have a possible soulution. My buddy had the same (lifter) type noise coming from his '87. Come to find out that when they re-installed the tranny, they pinched a grounding strap between the bellhousing and motor, and it was flicking off of the flexplate. VERY simple solution. Hopefully that's your problem!!! __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

06-01-2002, 03:52 AM	#13
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	Mine was a flexplate bolt, simple fix. thanks guys, __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

06-01-2002, 10:12 AM	#14
Zkast Account Suspended Join Date: May 2002 Location: Olathe, Kansas Posts: 929	Whew! One down........ One to go



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