Topic: Houston we have a problem
in Forum: C3 Engines
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Ash Fork, AZ - USA
Joined: 4/18/2007
Posts: 1058
Vette(s): 1981 Red Interior White exterior
So it sounds like I've thrown a rod. Any acceleration causes hard knocking, cruising does not. Before I start ripping the engine apart what could/should I look for?
I'm writing this while waiting for AAA.
Dave C..........My mantra: I can not be bought!! Long and short term leases available.
In the words of Zora Arkus-Duntov "Is your seat belt fastened? Alright, Let's go"
Yeah, I know, Shut up Dave.
Yeah, I know, Shut up Dave.
Lifetime Member #192


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Duncanville, TX - USA
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That SUX! Only other thing I can think of that can sound like that is possibly a cracked flywheel.....they can mimic rod noise. If it IS a bad rod, you should be able to feel it while driving, if it's bangin that hard. A rod noise usually doesn't go away like that, tho.....if it's bangin, it's bangin all the time. Then again, just depends on how bad the noise is....
Check the harmonic balancer on the front of the engine. The outter ring can slip rearward, and cause stoopid noises, too.
Joel Adams
C3VR Lifetime Member #56
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Where is the knock coming. From? Could it be something like timing- a spark, miss fire knock . Did you have oil pressure before knock? Temp, any idiot lights or gauges pegging?? Man , you really got the luck .H ope alls well, watch the back!!
Big al


Moderator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Good point, Al....could just be spark knock/pinging.....need a more definitive description....
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Ash Fork, AZ - USA
Joined: 4/18/2007
Posts: 1058
Vette(s): 1981 Red Interior White exterior
OK, I'm home. It's a HARD knock on the right lower(?) part of the engine. I can feel it in the peddle the same way you'd feel a sudden bass note. That's what made me think rod so I shut it down pretty fast. But there is no way that it would be gone when cruising, not quiet but gone, right? The distributor was slightly loose the other day and I tightened it back up. Maybe the timing is that off? It has been a little bit harder to start but I didn't think that much so I wasn't even thinking about it being a timing issue. Checked the oil again when I got it home and it's clean. Nothing I can see or feel as I was thinking the cam took a dump. I check the oil every other drive since the engine is so new. Oil pressure good. No idiot lights. Temp very good.
|UPDATED|6/10/2014 3:17:09 PM (AZT)|/UPDATED|
As far as having the luck lately...eh whatya going to do? Serious or not it gives my daughter and I a little bit more time under the hood together before she heads off to college in a year and a half.
|UPDATED|6/10/2014 3:17:09 PM (AZT)|/UPDATED|
Dave C..........My mantra: I can not be bought!! Long and short term leases available.
In the words of Zora Arkus-Duntov "Is your seat belt fastened? Alright, Let's go"
Yeah, I know, Shut up Dave.
Yeah, I know, Shut up Dave.
Lifetime Member #192


I had a cracked pulley ..the one on the crank that made a bad sound under acceleration. Couldn't see it, but could feel the crack with my fingers.
Alan

Ash Fork, AZ - USA
Joined: 4/18/2007
Posts: 1058
Vette(s): 1981 Red Interior White exterior
Oops, forgot to mention. I had a slight "poof" of smoke come out when I started it for the flatbed driver. I should have known better, those guys are usually drivers not mechanics.
Dave C..........My mantra: I can not be bought!! Long and short term leases available.
In the words of Zora Arkus-Duntov "Is your seat belt fastened? Alright, Let's go"
Yeah, I know, Shut up Dave.
Yeah, I know, Shut up Dave.
Lifetime Member #192


in Forum: C3 Engines
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