Make the bad noises go away! :whine: - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Critter · 12-02-2006, 11:53 PM

I just rebuilt my transmission. Took me about a month to learn as I went! Finally put it back in the Blazer, filled up all the fluids, started it and immediatly heard a knocking noise. Thought it was the transmission

All that work!!! Anyway, I slept on it and went out today to take a look at it. SOUNDS LIKE ITS THE MOTOR! The thing was sitting for about a month in my garage and ran fine when I parked it for the trans rebuild. Also, it looks like there is a fine mist of oil coming out of the passenger tail pipe, the same side as the sound (I think). It is a little deaper sounding that a lifter taping, so it has me a little worried thinking that its a pushrod or worse, connecting rod! Anyway, just thought I would share my grief.

*72CSTC5* · 12-03-2006, 12:07 AM

Pull your plugs and check them to see if you have excessive blowby on one of the cylinders or after you run it for a bit shoot it with a digital thermometer to check cylinder temperature difference if one cylinder is dead or do a compression test on the motor. You can rent a tester I believe from an auto supply store.

LUV2XCLR8 · 12-03-2006, 09:43 AM

Man that really does suck, here's hoping for the best

bagged74 · 12-03-2006, 12:15 PM

this may sound really stupid, but.....check and make sure the torque convertor bolts are tight. if they are loose it will make a terrible noise that sounds like the motor knocking. cracked flex plate also will make a similar noise.

RANDY COX · 12-03-2006, 07:18 PM

Bagged74,I was thinking the same thing,I use to have a 74 blazer 4x4 and the torque converter bolts had came loose and it knocked pretty good,so I would too check those bolts.hope this helps.

krue · 12-03-2006, 07:56 PM

Btdt on the t/c bolts.

Jtrux · 12-03-2006, 09:23 PM

I have a compression tester if you need to borrow it. I work til 4 during the week.

bouncytruck · 12-03-2006, 11:18 PM

I'll quadurple the note about the TC bolts,

bryanw1968 · 12-04-2006, 11:44 AM

Good chance it's the TC bolts. I had a '66 that had a BAD knock because of that.

If that's not it, you could have some stickiness in the valve train since it's been sitting so long. Through some Marvel's Mystery Oil in it if tightening the TC bolts doesn't help.

Also, I've never seen loose TC bolts make oil come out of one side of the motor

Critter · 12-04-2006, 12:39 PM

Quote:

Originally Posted by bryanw1968

Good chance it's the TC bolts. I had a '66 that had a BAD knock because of that.

If that's not it, you could have some stickiness in the valve train since it's been sitting so long. Through some Marvel's Mystery Oil in it if tightening the TC bolts doesn't help.

Also, I've never seen loose TC bolts make oil come out of one side of the motor

Yep, the oil spray from the tailpipe is what scares me. I didn't notice it doing it when I parked the thing. I was thinking though, it has been sitting for a while, maybe the oil was only from startup. Honestly, I really havn't had a chance to watch it real close. Same goes for the T/C bolts. I hope to look at it again tonight or tomorrow. Jtrux, I might be taking you up on your compression guage offer. Thanks for all the suggestions guys!

Critter · 12-08-2006, 11:55 AM

Ok, I made the bad noises go away myself. I am a little embarrassed to say this but…first of all the oil spray was just black water vapor. There is so much junk in my old exhaust, it is blowing out black crap everywhere. Second, the knocking was in the distributor area and was easily fixed. I guess the little “Un-tightening Demons” came in and worked their magic while I wasn’t looking.

Anyway, in my own defense, last night was the first chance I have had to really get my hands dirty and figure out what was wrong. It was fixed in under an hour. Thanks for the help.

Jtrux · 12-08-2006, 07:27 PM

You sure are brave to admit that. Oh, and don't try to act like you fixed it all by yourself...without me you would of had to fetch the tools yourself.

Critter · 12-09-2006, 12:39 AM

Quote:

Originally Posted by Jtrux

You sure are brave to admit that. Oh, and don't try to act like you fixed it all by yourself...without me you would of had to fetch the tools yourself.

Yeah, I figure we have to laugh at ourselves every now-and-then. I'm just happy it was nothing serious! And I appreciate the help, crawling up and down that grill can be a pain in the @ss. Your turn to make some progress.

12-02-2006, 11:53 PM	#1
Critter Future TOTM Winner Join Date: Aug 2006 Location: Bulverde, TX Posts: 2,692	Make the bad noises go away! :whine: I just rebuilt my transmission. Took me about a month to learn as I went! Finally put it back in the Blazer, filled up all the fluids, started it and immediatly heard a knocking noise. Thought it was the transmission All that work!!! Anyway, I slept on it and went out today to take a look at it. SOUNDS LIKE ITS THE MOTOR! The thing was sitting for about a month in my garage and ran fine when I parked it for the trans rebuild. Also, it looks like there is a fine mist of oil coming out of the passenger tail pipe, the same side as the sound (I think). It is a little deaper sounding that a lifter taping, so it has me a little worried thinking that its a pushrod or worse, connecting rod! Anyway, just thought I would share my grief. __________________ 72 Chevy CST K5 HIGHLANDER BLAZER Getting a 6.0,NV4500,NP205,14BFF (Currently laying all over the place in little pieces) 72 Chevy swb step-side "LS" 6.0 Here's a build thread of sorts 2002 HD2500 Crew Cab, 8.1L Allison 4x4 Daily Driver Check it out www.lsdyno.com Last edited by Critter; 12-02-2006 at 11:54 PM.

12-03-2006, 12:07 AM	#2
72CSTC5 Account Suspended Join Date: Nov 2004 Location: Deer Park, Tx. Posts: 2,522	Re: Make the bad noises go away! :whine: Pull your plugs and check them to see if you have excessive blowby on one of the cylinders or after you run it for a bit shoot it with a digital thermometer to check cylinder temperature difference if one cylinder is dead or do a compression test on the motor. You can rent a tester I believe from an auto supply store.

12-03-2006, 09:43 AM	#3
LUV2XCLR8 The LuvShack Garage Join Date: Jan 2004 Location: Maple Grove, TN (West Side) Posts: 30,468	Re: Make the bad noises go away! :whine: Man that really does suck, here's hoping for the best __________________ Owner/Op: "TN Classic Transport Carriers" The Toy: "Square Vette" 72 Hybrid Blazer Toy Barn: "LuvShack" 40 x 60 x 20 Shop Tow Piggy:"Maddy" 88 Silverado 3500 Hauler: "Feathers" 14 Aluma 8218T

12-03-2006, 12:15 PM	#4
bagged74 its just $$$$$ Join Date: Jul 2003 Location: OK Posts: 2,078	Re: Make the bad noises go away! :whine: this may sound really stupid, but.....check and make sure the torque convertor bolts are tight. if they are loose it will make a terrible noise that sounds like the motor knocking. cracked flex plate also will make a similar noise.

12-03-2006, 07:18 PM	#5
RANDY COX Registered User Join Date: Mar 2001 Location: RADFORD, VA Posts: 2,651	Re: Make the bad noises go away! :whine: Bagged74,I was thinking the same thing,I use to have a 74 blazer 4x4 and the torque converter bolts had came loose and it knocked pretty good,so I would too check those bolts.hope this helps. __________________ 1964 BBC 402 4x4

12-03-2006, 07:56 PM	#6
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Re: Make the bad noises go away! :whine: Btdt on the t/c bolts. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

12-03-2006, 09:23 PM	#7
Jtrux I'm a poor spectator Join Date: Aug 2006 Location: San Antonio, Tx Posts: 2,287	Re: Make the bad noises go away! :whine: I have a compression tester if you need to borrow it. I work til 4 during the week. __________________ 2006 Jeep Unlimited IMPACT ORANGE 1993 Chevy 2500 4x4 ExCab LWB 454/NV4500 Tow rig 1977 Ford F100 2x4 LWB 1st truck I owned, still have it!!! 1979 Ford F150 4x4 SWB Built Ford Tough!!! 1971 Chevy Blazer 350 / SM465 / NP205 UNDER CONSTRUCTION Soon to have a LQ4 6.0!!!

12-03-2006, 11:18 PM	#8
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	Re: Make the bad noises go away! :whine: I'll quadurple the note about the TC bolts, __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

12-04-2006, 11:44 AM	#9
bryanw1968 Senior Member Join Date: Jul 2006 Location: Leander, Texas Posts: 850	Re: Make the bad noises go away! :whine: Good chance it's the TC bolts. I had a '66 that had a BAD knock because of that. If that's not it, you could have some stickiness in the valve train since it's been sitting so long. Through some Marvel's Mystery Oil in it if tightening the TC bolts doesn't help. Also, I've never seen loose TC bolts make oil come out of one side of the motor

12-08-2006, 11:55 AM	#11
Critter Future TOTM Winner Join Date: Aug 2006 Location: Bulverde, TX Posts: 2,692	Re: Make the bad noises go away! :whine: Ok, I made the bad noises go away myself. I am a little embarrassed to say this but…first of all the oil spray was just black water vapor. There is so much junk in my old exhaust, it is blowing out black crap everywhere. Second, the knocking was in the distributor area and was easily fixed. I guess the little “Un-tightening Demons” came in and worked their magic while I wasn’t looking. Anyway, in my own defense, last night was the first chance I have had to really get my hands dirty and figure out what was wrong. It was fixed in under an hour. Thanks for the help. __________________ 72 Chevy CST K5 HIGHLANDER BLAZER Getting a 6.0,NV4500,NP205,14BFF (Currently laying all over the place in little pieces) 72 Chevy swb step-side "LS" 6.0 Here's a build thread of sorts 2002 HD2500 Crew Cab, 8.1L Allison 4x4 Daily Driver Check it out www.lsdyno.com

12-08-2006, 07:27 PM	#12
Jtrux I'm a poor spectator Join Date: Aug 2006 Location: San Antonio, Tx Posts: 2,287	Re: Make the bad noises go away! :whine: You sure are brave to admit that. Oh, and don't try to act like you fixed it all by yourself...without me you would of had to fetch the tools yourself. __________________ 2006 Jeep Unlimited IMPACT ORANGE 1993 Chevy 2500 4x4 ExCab LWB 454/NV4500 Tow rig 1977 Ford F100 2x4 LWB 1st truck I owned, still have it!!! 1979 Ford F150 4x4 SWB Built Ford Tough!!! 1971 Chevy Blazer 350 / SM465 / NP205 UNDER CONSTRUCTION Soon to have a LQ4 6.0!!!

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