Corvette consistent problems or defects
Thread Starter
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
LT1/4 Opti-Spark. My '96 with 75k on it is on Opti number...hmm, lets see, 1...2...3...4...5...6, yep, 6. 6 in three years and 3500mi. That doesn't count the one the previous owner put in @ 55k. All work was done under warranty. Horrible design. When it works it works great but... At some point everyone has to replace it along with the water pump.
I like It!
Being a C3 guy I need more info, Thanks for the reply!
I've owned a '85 and currently own a '93. I haven't had any major problems with either (except the usual oil leaks noted in this thread and on the '93, PKE not working right). In '89, '90, and possibly '91, the C4 had the crappy Multec injectors. Good luck with your project. 
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
This is a good thread.
I dont know if this is a normal problem but both lumbar supports have gone out in my 93. I assume i need to replace the motor but they are way to expensive.
WATER LEAKS!!!
I dont know if this is a normal problem but both lumbar supports have gone out in my 93. I assume i need to replace the motor but they are way to expensive.
WATER LEAKS!!!
Le Mans Master
Joined: Aug 2005
Posts: 5,002
Likes: 5
From: No Opti Here Tn
St. Jude Donor '06
Opti in LT1 and LT4 gets moisture in it and that fries it
I love my LT5
The fact that they put it under the water pump was just
What does a water pump do when it begins to fail Thats right it weeps water onto the opti
The headlight bushings were also something that will go bad on every C4 there is
I love my LT5
The fact that they put it under the water pump was just
What does a water pump do when it begins to fail Thats right it weeps water onto the opti
The headlight bushings were also something that will go bad on every C4 there is
Le Mans Master
Joined: Sep 2005
Posts: 6,551
Likes: 36
From: Jenks OK
Thread Starter
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
Opti in LT1 and LT4 gets moisture in it and that fries it
I love my LT5
The fact that they put it under the water pump was just
What does a water pump do when it begins to fail Thats right it weeps water onto the opti
The headlight bushings were also something that will go bad on every C4 there is
I love my LT5
The fact that they put it under the water pump was just
What does a water pump do when it begins to fail Thats right it weeps water onto the opti
The headlight bushings were also something that will go bad on every C4 there is
Safety Car
Joined: Aug 2004
Posts: 4,908
Likes: 735
From: Southwest Kansas
2022 Corvette of the Year Finalist -- Unmodified
2021 C6 of the Year Winner - Unmodified
Lumbar inflation support problems are common. Many times it's the little rubber diaphragm that has a hole in it and can be replaced fairly easily, but could be the motor.
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Heel & Toe
Joined: Oct 2007
Posts: 19
Likes: 0
I am new but....
The best advice you could give to anyone buying a used car/vette is to drive it several miles on different road surfaces, different speeds and if seller refuses it, move on to the next vette.
I had good luck with used cars in general, and my vette is no different, but I learn quite a bit here. The leaks in the targa top is driving me mad, is the only thing wrong with my 94.
An idea for your project maybe to formulate a brief rating questionare from vette owners. Use the comments here to compose it.
Good luck with your project.
I had good luck with used cars in general, and my vette is no different, but I learn quite a bit here. The leaks in the targa top is driving me mad, is the only thing wrong with my 94.
An idea for your project maybe to formulate a brief rating questionare from vette owners. Use the comments here to compose it.
Good luck with your project.
Thread Starter
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
The best advice you could give to anyone buying a used car/vette is to drive it several miles on different road surfaces, different speeds and if seller refuses it, move on to the next vette.
I had good luck with used cars in general, and my vette is no different, but I learn quite a bit here. The leaks in the targa top is driving me mad, is the only thing wrong with my 94.
An idea for your project maybe to formulate a brief rating questionare from vette owners. Use the comments here to compose it.
Good luck with your project.
I had good luck with used cars in general, and my vette is no different, but I learn quite a bit here. The leaks in the targa top is driving me mad, is the only thing wrong with my 94.
An idea for your project maybe to formulate a brief rating questionare from vette owners. Use the comments here to compose it.
Good luck with your project.
Is this a common problem, know to many?
Le Mans Master
Joined: Sep 2005
Posts: 6,551
Likes: 36
From: Jenks OK
My understanding is that the '84-'86 alternators are better then the later ones. They switched designs at some point and they had more problems.
Thread Starter
Race Director
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2018 Corvette of Year Finalist
2017 C3 of Year
Le Mans Master
Joined: Sep 2005
Posts: 6,551
Likes: 36
From: Jenks OK
Actually there is a tech tip about it, basically 84 and 85 used an older style of alternator, GM had a new and improved one, which had a bit low of an output for the needs of the engine, and so there is yet another alternator which is the same basic design but beefier that they started using in the Zr-1's and later LT-1/4 corvettes.
There are parts to retrofit this alternator on the older corvettes.
There are parts to retrofit this alternator on the older corvettes.
Thread Starter
Race Director
Joined: Jun 2005
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2018 Corvette of Year Finalist
2017 C3 of Year
Actually there is a tech tip about it, basically 84 and 85 used an older style of alternator, GM had a new and improved one, which had a bit low of an output for the needs of the engine, and so there is yet another alternator which is the same basic design but beefier that they started using in the Zr-1's and later LT-1/4 corvettes.
There are parts to retrofit this alternator on the older corvettes.
There are parts to retrofit this alternator on the older corvettes.
Thanks
Heel & Toe
Joined: Oct 2007
Posts: 17
Likes: 0
From: SW FL
We bought our '86 convertible with 70,000 miles on it sunday and reading through a ton of threads here, some of the common problem areas have been addressed on ours when I looked it over: new alternater, new brake booster, new window regulator assembly in the drivers door (failed weld but fixed last night), and the window and power door lock switches all need replacing (they're just falling apart). It also needs a new rear window, but 22 years of Florida will do that to plastic.
Edit: Lumbar doesn't work either, haven't had a chance to check those switches or tear the seats apart yet.
Edit: Lumbar doesn't work either, haven't had a chance to check those switches or tear the seats apart yet.
Last edited by mndwgz; Oct 24, 2007 at 12:40 PM. Reason: lumbar
Team Owner
Joined: Jun 2001
Posts: 26,196
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From: Orlando FL
St. Jude Donor '08-'09
windshield leaks
weatherstripping leaks (everywhere) - test heavily with a hose
targa top separating from frame
L98 head gaskets blow easily with higher milage if original
LCD Dash panels going bad
VATS acting up
shoot you know what... just write the entire car down as a "consistent problem" LOL
weatherstripping leaks (everywhere) - test heavily with a hose
targa top separating from frame
L98 head gaskets blow easily with higher milage if original
LCD Dash panels going bad
VATS acting up
shoot you know what... just write the entire car down as a "consistent problem" LOL
Thread Starter
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
We bought our '86 convertible with 70,000 miles on it sunday and reading through a ton of threads here, some of the common problem areas have been addressed on ours when I looked it over: new alternater, new brake booster, new window regulator assembly in the drivers door (failed weld but fixed last night), and the window and power door lock switches all need replacing (they're just falling apart). It also needs a new rear window, but 22 years of Florida will do that to plastic.
windshield leaks
weatherstripping leaks (everywhere) - test heavily with a hose
targa top separating from frame
L98 head gaskets blow easily with higher milage if original
LCD Dash panels going bad
VATS acting up
shoot you know what... just write the entire car down as a "consistent problem" LOL
weatherstripping leaks (everywhere) - test heavily with a hose
targa top separating from frame
L98 head gaskets blow easily with higher milage if original
LCD Dash panels going bad
VATS acting up
shoot you know what... just write the entire car down as a "consistent problem" LOL
Good luck thanks for the input
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
Well, the motor doesnt run at all when i hit the button. That leads me to believe that it is shot.
Race Director
Joined: Dec 2003
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From: Fremont Ca
2022 C4 of the Year Finalist - Modified
84-87 steering racks fail,84 early 86 window regs are junk,A.C. pulley is junk on the early cars.The windshields on early ZR1s delaminate.Once all this info is compiled and put in a book,there wont be anything positive to say about the car.These cars are junk and anybody thats ever worked on one knows that.And you cant forget the paint,from 84 to about 88 the paint falls off the car.