84 c10 bearings/head gasket? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cfan10 · 08-03-2017, 03:11 AM

Ok, quick question what are the tell tale signs of spun rod bearing?
I do not have the truck near me to pull the pan and check, I met a guy at the salvage yard with a square body blazer he tells me it sounds more like a head gasket to him. Someone on YouTube also suggested the same thing.

From memory it tapped, smoked and wouldn't pick up very much speed added oil and it didn't burn it up, but dipstick was dry before adding oil. But did sound/feel as if it wanted to kill. Very slight coolant on intake manifold before.

Started right up, then the tapping and slight smoke.

84 305v8/th350

New parts
Alt.
Dist.
Batt.
Hoses
Belts
Fairly new driveworks waterpump
Tune up
Oil change driveworks oil filter

As always many thanks for your advice/experience it is tremendously appreciated!!!

cadillac_al · 08-03-2017, 06:27 AM

Knocking rod bearings are more common than knocking head gaskets. I have never heard a head gasket that sounded like a rod bearing. A rod knock has a very metallic bang to it. A lot like a small hammer banging on my welding table.

sweetk30 · 08-03-2017, 09:13 AM

and a bearing going bad or spun = lower oil pressure .

**old Rusty C10** · 08-03-2017, 10:07 AM

get yourself a stethoscope or a large extension and listen tot he block a bearing will knock loudest near the crank and a head will be up top but it ifs making a banging noise 9 of 10 its a bearing

Dead Parrot · 08-03-2017, 10:45 AM

If it ran out of oil or was short for many miles, could be bearings, either rod or piston, and/or bad cam lobes. Probably didn't do the cylinder walls any good either.

If thinking about purchasing, safest way is to make an offer with the assumption you will be replacing the motor.

Blown head gasket often effects two adjacent cylinders.

abig84 · 08-04-2017, 06:38 PM

my first k5 had spun bearings when i got it, it just made a loud knocking sound. i actually drove it that way for a few hundred miles before pulling the pan and putting in a slightly oversized bearing on the gouged up crank. made the knocking a little quieter.

didnt smoke or run bad or anything else. no idea on oil pressure as the gauge was broken

andyh1956 · 08-05-2017, 07:12 PM

A rod knock is a "Double Knock", if severely worn or spun the piston can reach the bottom of the head!
Sounds like your engine has multiple symptoms.

08-03-2017, 03:11 AM	#1
cfan10 Registered User Join Date: May 2011 Location: Texas Posts: 977	84 c10 bearings/head gasket? Ok, quick question what are the tell tale signs of spun rod bearing? I do not have the truck near me to pull the pan and check, I met a guy at the salvage yard with a square body blazer he tells me it sounds more like a head gasket to him. Someone on YouTube also suggested the same thing. From memory it tapped, smoked and wouldn't pick up very much speed added oil and it didn't burn it up, but dipstick was dry before adding oil. But did sound/feel as if it wanted to kill. Very slight coolant on intake manifold before. Started right up, then the tapping and slight smoke. 84 305v8/th350 New parts Alt. Dist. Batt. Hoses Belts Fairly new driveworks waterpump Tune up Oil change driveworks oil filter As always many thanks for your advice/experience it is tremendously appreciated!!! __________________ Rest In Peace:Mikhail {Mickey Rooney} Alpha 2/5/13 Omega 7/22/14 10:28AM I love you tremendously and outragiously Superpuppi Thai Ridgeback...The most intelligent dog known to me. Don't mess with my truck, my momma or my money...not necessarily in that order. © Stand for something or fall for anything. [LIST][*]'98 Bourbon St. Brawl ©2010

08-03-2017, 06:27 AM	#2
cadillac_al Registered User Join Date: Oct 2013 Location: Maine Posts: 2,353	Re: 84 c10 bearings/head gasket? Knocking rod bearings are more common than knocking head gaskets. I have never heard a head gasket that sounded like a rod bearing. A rod knock has a very metallic bang to it. A lot like a small hammer banging on my welding table. __________________ 76 Chevy K20 76 GMC K15 77 Chevy C10 77 Chevy K10

08-03-2017, 09:13 AM	#3
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: 84 c10 bearings/head gasket? and a bearing going bad or spun = lower oil pressure . __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great.

08-03-2017, 10:07 AM	#4
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,277	Re: 84 c10 bearings/head gasket? get yourself a stethoscope or a large extension and listen tot he block a bearing will knock loudest near the crank and a head will be up top but it ifs making a banging noise 9 of 10 its a bearing __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

08-03-2017, 10:45 AM	#5
Dead Parrot Registered User Join Date: Aug 2012 Location: Oklahoma City, OK Posts: 2,517	Re: 84 c10 bearings/head gasket? If it ran out of oil or was short for many miles, could be bearings, either rod or piston, and/or bad cam lobes. Probably didn't do the cylinder walls any good either. If thinking about purchasing, safest way is to make an offer with the assumption you will be replacing the motor. Blown head gasket often effects two adjacent cylinders.

08-04-2017, 06:38 PM	#6
abig84 Registered User Join Date: Jan 2017 Location: wheaton IL Posts: 659	Re: 84 c10 bearings/head gasket? my first k5 had spun bearings when i got it, it just made a loud knocking sound. i actually drove it that way for a few hundred miles before pulling the pan and putting in a slightly oversized bearing on the gouged up crank. made the knocking a little quieter. didnt smoke or run bad or anything else. no idea on oil pressure as the gauge was broken

08-05-2017, 07:12 PM	#7
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: 84 c10 bearings/head gasket? A rod knock is a "Double Knock", if severely worn or spun the piston can reach the bottom of the head! Sounds like your engine has multiple symptoms.



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