03-19-2019 | #1 |
Join Date: Sep 2018
Location: Groton, CT
Posts: 384
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Connecting rod bolts
I've got a light knock that I hear around 2000 -2500 rpm that's driving me nuts. Above that rpm, there's too much other noise for my 1/2 deaf ears to hear it.
Not sure what it is, but I want to pull the rod caps and check the bearings. The last owner lost an oil cooler hose, but I don't know how far the car was driven after the hose let go. Anyway, since the rod bolt torque is so many ft/lbs plus 1/4 turn (or something like that), I'm wondering if the stretched bolts are one time use and should be replaced. Thanks in advance...
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1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige |
03-19-2019 | #2 |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,169
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Re: Connecting rod bolts
Is it a consistent knock? Do you here it at lower rpm? Have you checked your Dual Mass flywheel? Those will make the motor sound like it it knocking.
Does this happen when the motor is cold? Warm? Both?
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
03-19-2019 | #3 |
Join Date: Feb 2012
Location: Ledyard,CT
Posts: 8,256
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Re: Connecting rod bolts
Tensioner?
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03-19-2019 | #4 | |
Join Date: Sep 2018
Location: Groton, CT
Posts: 384
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Re: Connecting rod bolts
Quote:
Knock is consistent either cold or hot. Driven about 1000 miles since I bought the car, hasn't gotten any better or worse. Only hear it at lower rpms, 2000-2500-ish, only during acceleration or under load. At higher rpms, there's too much road noise to hear it. No knock while steady cruise, coasting or slowing from what I can hear. No knock at idle.
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1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige |
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03-19-2019 | #5 |
Join Date: Nov 2007
Location: Sunshine State
Posts: 1,071
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Re: Connecting rod bolts
Can you capture the sound on video?
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[B]1990 #2815[/B] [COLOR="Red"][B]Red/Red[/B][/COLOR] Ported Plenum & IH (by Pete) Haibeck Chip Rebuilt FPR (by Phil) FIC Injectors Watson LT Headers 3" Stainless Works exhaust Lingenfelter Open Air Lid Bill B Built Transmission Shifter & C Beam Plates [FONT=Impact][COLOR=red]1992 [COLOR=black]#[/COLOR] 091[/COLOR][/FONT] [FONT=Impact][COLOR=#ff0000]Red/[COLOR=silver]Gray[/COLOR][/COLOR][/FONT] [B]SOLD[/B] |
03-19-2019 | #6 |
Join Date: Sep 2018
Location: Groton, CT
Posts: 384
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Re: Connecting rod bolts
Don't think so. Quiet at idle or revving in neutral. Only under load/acceleration.
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1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige |
03-19-2019 | #7 |
Join Date: Sep 2018
Location: Groton, CT
Posts: 384
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Re: Connecting rod bolts
Already tried the video thing. Phone can't pick it up while driving. It's not that loud. Sounds like a quiet version of a single rod knock.
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1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige |
03-19-2019 | #8 |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,169
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Re: Connecting rod bolts
Stethoscope might help to pin point location of noise too? Might be there at idle just not heard
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
03-19-2019 | #9 |
Join Date: Jan 2015
Location: Marietta, GA USA
Posts: 1,160
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Re: Connecting rod bolts
Seems like the rod knocks I've heard could be heard even at low RPM's. But (fortunately) I haven't heard many.
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03-19-2019 | #10 | |
Join Date: Sep 2018
Location: Groton, CT
Posts: 384
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Re: Connecting rod bolts
Quote:
Yup, already tried the Stethoscope, both at idle and higher rpm. Couldn't hear anything without the engine loaded. So, back to the original question..... are the rod bolts reuseable, or do I need replacement bolts?
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1992 ZR1 #442, 2 tops, White, White, Haibeck 415, 3.90 gear, Coilovers 2018 Audi RS5, 2.9 V6 Twin Turbo, Auto, Black, Black 2021 Audi Q3, 2.0T, 8 spd Tiptronic, Navarro Blue metallic, Pearl Beige |
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