84 C10 with I6 -Rod knock? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

85Bowtie · 05-31-2010, 11:58 PM

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.

capriceutah · 06-01-2010, 11:56 AM

Quote:

Originally Posted by 85Bowtie

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 · 06-02-2010, 10:12 PM

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 · 08-10-2010, 12:43 AM

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?

05-31-2010, 11:58 PM	#1
85Bowtie Registered User 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.

06-02-2010, 10:12 PM	#3
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.

08-10-2010, 12:43 AM	#4
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?



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