The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 05-31-2010, 10:38 AM   #1
capriceutah
Registered User
 
Join Date: Oct 2007
Location: Midvale, UT
Posts: 40
84 C10 with I6 -Rod knock?

I just picked this truck up from an 85 year old guy that had 5 cars and his wife can't drive. He had a reciept for a new motor and trans. First thing that was noticable is rocker noise. I adjusted the rockers by pulling the valve cover and starting,then turned until the ticking started and then turned it back until it stopped- went a 1/4 turn and then 1/8 turn. The motor doesn't smoke at all.

Can timing cause this sound??

Thanks in Advance,
Chris

Here is a movie of what I'm hearing


It did get quieter and then I seaformed the motor and it got even quieter. I changed the oil and it was black but nothing out of the ordinary.

Last edited by capriceutah; 05-31-2010 at 10:46 AM.
capriceutah is offline   Reply With Quote
Old 05-31-2010, 11:19 AM   #2
CLASSIC87'
OL BLUU
 
CLASSIC87''s Avatar
 
Join Date: Mar 2004
Location: WICHITA, KS.
Posts: 1,065
Re: 84 C10 with I6 -Rod knock?

take a wood/metal rod and put it on different places of the engine and listen in the end of it... normally you can al least find out where the noise is coming from.
CLASSIC87' is offline   Reply With Quote
Old 05-31-2010, 12:43 PM   #3
capriceutah
Registered User
 
Join Date: Oct 2007
Location: Midvale, UT
Posts: 40
Re: 84 C10 with I6 -Rod knock?

The fuel pump has a lot of racket when I touched it with the piece of wood - can that cause the noise also I heard it through the exhaust too
capriceutah is offline   Reply With Quote
Old 05-31-2010, 09:57 PM   #4
f.monroe
Senior Member
 
f.monroe's Avatar
 
Join Date: May 2004
Location: Caldwell,Tx.
Posts: 3,648
Re: 84 C10 with I6 -Rod knock?

I would look at the flexplate/flywheel bolts . I have seen them come loose after an engine trans install . If it is an auto , also check the torque converter bolts.
Frank
__________________
Born and proudly residing in a Red State !
f.monroe is offline   Reply With Quote
Old 05-31-2010, 11:58 PM   #5
85Bowtie
Registered User
 
85Bowtie's Avatar
 
Join Date: Mar 2009
Location: TN
Posts: 410
Re: 84 C10 with I6 -Rod knock?

That doesn't sound like a rod knock. A rod knocking has a deep sound to it, kind of like stomping your foot on the ground. That sounds like something either in your valvetrain or possibly piston slap. I can't tell from an internet video, piston slap isn't usually THAT noisy but the video might over exaggerate it. It also usually goes away once the motor warms up and the pistons expand and create a tighter fit in the cylinder.
__________________
'69 Dodge Charger R/T 440, 727, 3.55 Sure Grip
'68 Plymouth Road Runner 383, 727, 3.23 Sure Grip
'89 Dodge Diplomat ex cop car 408, 727, 3.55 Sure Grip
'77 Dodge Monaco ex cop car 440, 727, 2.71
'79 Dodge 'Lil Red Express pickup 360, 727, 3.55 Sure Grip
'12 Dodge Challenger SRT8 392, M6, 3.92
'85 Chevrolet C-10 SWB 2wd 305, TH350, 2.73

Last edited by 85Bowtie; 05-31-2010 at 11:59 PM.
85Bowtie is offline   Reply With Quote
Old 06-01-2010, 10:07 AM   #6
Desert1957
Registered User
 
Desert1957's Avatar
 
Join Date: Apr 2009
Location: New Freedom Pa.
Posts: 1,335
Re: 84 C10 with I6 -Rod knock?

Quote:
Originally Posted by f.monroe View Post
I would look at the flexplate/flywheel bolts . I have seen them come loose after an engine trans install . If it is an auto , also check the torque converter bolts.
Frank
Yes loose bolts , also GM flex plates can crack between the large holes...

Desert
Desert1957 is offline   Reply With Quote
Old 06-01-2010, 11:56 AM   #7
capriceutah
Registered User
 
Join Date: Oct 2007
Location: Midvale, UT
Posts: 40
Re: 84 C10 with I6 -Rod knock?

Quote:
Originally Posted by 85Bowtie View Post
That doesn't sound like a rod knock. A rod knocking has a deep sound to it, kind of like stomping your foot on the ground. That sounds like something either in your valvetrain or possibly piston slap. I can't tell from an internet video, piston slap isn't usually THAT noisy but the video might over exaggerate it. It also usually goes away once the motor warms up and the pistons expand and create a tighter fit in the cylinder.
It is a constant sound- No change when it is warmed up.

it is a 3 speed auto with a newer trans with 15 K on it

I did notice that the cat converter has a quarter size hole in it and so does the muffler. I'm thinking of replacing the exhaust along with a new fuel pump. I will pull the flywheel cover and check the bolts tonight if I have time.
capriceutah is offline   Reply With Quote
Old 06-02-2010, 10:12 PM   #8
capriceutah
Registered User
 
Join Date: Oct 2007
Location: Midvale, UT
Posts: 40
Re: 84 C10 with I6 -Rod knock?

Bump.

Checking the receipt for the motor-flywheel is new
Verified bolts are tight on the torq converter and no cracks in the flywheel.
capriceutah is offline   Reply With Quote
Old 08-10-2010, 12:43 AM   #9
capriceutah
Registered User
 
Join Date: Oct 2007
Location: Midvale, UT
Posts: 40
Re: 84 C10 with I6 -Rod knock?

Update

New exhaust and the truck passes emissions with no problems at all. Still ticking but not as bad and it starts with two pumps of the gas.

Fuel pump is new-that helped it run better. I'm driving it everyday, the shop that did emissions said they thought it could be the lifter

Any suggestions?
capriceutah is offline   Reply With Quote
Old 08-10-2010, 09:20 AM   #10
Davidmichael
Registered User
 
Davidmichael's Avatar
 
Join Date: Jun 2010
Location: Pittsburgh PA
Posts: 686
Re: 84 C10 with I6 -Rod knock?

It's hard from a video to know exactly what it is, but it definitely sounds like something in valve train. Agreed that it does not sound like a piston, but you never know. I would try more top end work and see if you can narrow it down some.
__________________
86 Suburban 2WD = rolled it and totaled it
83 LWB STD Cab 4x4 = went to the scrapper. Was my baby.
84 Suburban 2WD = stripped it/ scrapped it
81 8 foot bed made into a trailer
86 Suburban going to be made into a trailer
91 Suburban 4x4 = that's my baby
00 S10 Xtreme STD Cab
01 S10 ZR2
Davidmichael is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:46 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com