C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

1990 zr1

Thread Tools
 
Search this Thread
 
Old May 14, 2018 | 02:29 PM
  #1  
gLomeli's Avatar
gLomeli
Thread Starter
5th Gear
 
Joined: May 2018
Posts: 5
Likes: 0
Default 1990 zr1

I have a 1990 ZR1 with 17000 miles. There is a knocking noise around flywheel area and a mechanic thinks it may be the crankshaft thrust bearing. Can you advise on signs of this problem and cost re: repairs? I find it difficult to believe it can be this problem with such low mileage...,Thanks
Reply
Old May 14, 2018 | 03:04 PM
  #2  
Route99's Avatar
Route99
Race Director
Supporting Lifetime
St. Jude 10 Year Donor
Photogenic
Loved
Community Favorite
 
Joined: Apr 2017
Posts: 10,247
Likes: 888
From: Hickory NC
2025 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
2020 C5 of the Year Finalist - Modified
St. Jude Donor '17 thru '26
Default

Welcome to the forum and congratulations on your C4 ZR1!
You should post your question in the C4 section of the forum. Lots of great members and helpful info there. https://www.corvetteforum.com/forums...-1984-1996-19/.
Best wishes that this is an easy and inexpensive fix.

You may want to add some other info that could help the members there better address your concern, such as:
Does the noise appear all the time? Is the noise more noticeable when the engine is cold or when it's hot? Is the noise RPM dependent (more noise with more engine RPM)? Is the engine running rough? etc

Last edited by Route99; May 14, 2018 at 03:11 PM.
Reply
Old May 14, 2018 | 05:46 PM
  #3  
Vetteman Jack's Avatar
Vetteman Jack
Administrator
Supporting Lifetime
Veteran: Navy
St. Jude 20 Year Donor
25 Year Member
Veteran: Reserves
 
Joined: Mar 2001
Posts: 368,060
Likes: 24,730
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Default

Moved to C4 Tech.
Reply
Old May 14, 2018 | 06:02 PM
  #4  
C409's Avatar
C409
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2005
Posts: 6,478
Likes: 565
From: Clearwater Florida
Default

..... I'm pretty sure that the LT5's used a dual mass flywheel and they are prone to making strange noises .....
Reply
Old May 14, 2018 | 06:14 PM
  #5  
gLomeli's Avatar
gLomeli
Thread Starter
5th Gear
 
Joined: May 2018
Posts: 5
Likes: 0
Default

Thank you all for your great input. I just received a call from my mechanic who found that the issue was with the flywheel. Won’t be cheap to repair, but much better than a thrust bearing or other engine problem!
Reply
Old May 14, 2018 | 07:44 PM
  #6  
ChumpVette's Avatar
ChumpVette
Safety Car
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2010
Posts: 4,564
Likes: 1,676
Default

Probably not the flywheel either. ZR-1's are prone to making the noise you describe with a misfire. Check plugs, plug wires, coils, and injectors.
Reply
Old May 14, 2018 | 08:51 PM
  #7  
gLomeli's Avatar
gLomeli
Thread Starter
5th Gear
 
Joined: May 2018
Posts: 5
Likes: 0
Default

  • will do thanks
Reply
Old May 14, 2018 | 10:15 PM
  #8  
billschroeder5842's Avatar
billschroeder5842
Zen Vet Master Level VII
Supporting Gold
Veteran: Navy
10 Year Member
Liked
Loved
 
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Default

Originally Posted by C409
..... I'm pretty sure that the LT5's used a dual mass flywheel and they are prone to making strange noises .....
When I first got mine, the dual flywheel noise scared me until I learned what it was. Now, I listen for it as it tells me everything is normal.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-1

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-2

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-3

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-4

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-5

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-6

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-7

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-8

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-9

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
Old May 14, 2018 | 10:37 PM
  #9  
gLomeli's Avatar
gLomeli
Thread Starter
5th Gear
 
Joined: May 2018
Posts: 5
Likes: 0
Default

Thanks
Reply
Old May 15, 2018 | 07:55 AM
  #10  
C409's Avatar
C409
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2005
Posts: 6,478
Likes: 565
From: Clearwater Florida
Default

..... I have also heard that the ZF trans can be noisy if the wrong oil is used .....
Reply
Old May 15, 2018 | 11:11 AM
  #11  
FASTAZU's Avatar
FASTAZU
Race Director
20 Year Member
Veteran: Navy
Community Favorite
Top Answer: 3
 
Joined: Feb 2002
Posts: 11,610
Likes: 1,053
From: Compound in the Grove, Ga.
2026 Corvette of the Year Finalist - Unmodified
2025 C4 of the Year Winner - Unmodified
2024 C4 of the Year Finalist - Unmodified
2020 C3 of the Year Finalist - Unmodified
2019 C4 of Year Finalist (performance mods)
2018 C4 of Year Finalist
2015 C4 of the Year Finalist
St. Jude Donor '16
Default

Yes the DM is noisy the 90 had a black tag ZF6 also noisy and a miss fire will make it worse.

http://www.zr1.net/forum/
Reply
Old May 15, 2018 | 12:34 PM
  #12  
383vett's Avatar
383vett
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2003
Posts: 17,699
Likes: 1,667
From: moraga ca
Default

A bad thrust bearing would result in increased crankshaft endplay which can be checked in one minute with the car on a lift.
Reply

Get notified of new replies

To 1990 zr1





All times are GMT -4. The time now is 10:51 AM.

story-0
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-1
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-2
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-3
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-4
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-5
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-6
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-7
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-8
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-9
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE