explain the reason for this??
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 1,156
Likes: 1
From: Pittsburgh Pirates PA
explain the reason for this??
why when someone asks about a certain corvette the reply is always "be careful of the opti spark." can someone explain the big deal? of course it is a pain, and bad design, by the water pump, etc.. but it is not like it cost thousands of dollars to repair. we spend hundreds on tires, exhausts, brakes, and mods. why is opti more of a nightmare than tires? if it goes, get a new one. like anything. is there something i am missing... please help me understand. i have a 95, so i assume i have one too, and expect to replace it when it goes bad. thanks!!!
Team Owner
Joined: Sep 2001
Posts: 62,146
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
You have a 95, so when yours gets wet, its not a problem.
Earlier models, once it gets wet, its toast, and its not cheap. I remember some people being charged nearly $1000 for R&R of the thing.
Earlier models, once it gets wet, its toast, and its not cheap. I remember some people being charged nearly $1000 for R&R of the thing.
Melting Slicks
Joined: Oct 1999
Posts: 2,501
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From: Houston, Texas FEAR THE BONES
2023 C5 of the Year Finalist - Modified
1) Its expensive (around $300 at cost)
2) Usually have to replace the water pump, too ($150 at cost)
3) Pain in the *** location to get to.
4) Heck of alot of effort involved just to reach it (drain coolant, pull water pump, pull plug wires, etc.)
5) Every minute you are working on it, you are cursing the GM engineers who designed it and located it on the engine
2) Usually have to replace the water pump, too ($150 at cost)
3) Pain in the *** location to get to.
4) Heck of alot of effort involved just to reach it (drain coolant, pull water pump, pull plug wires, etc.)
5) Every minute you are working on it, you are cursing the GM engineers who designed it and located it on the engine
Advanced
Joined: May 2004
Posts: 96
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From: Bon Aqua tn
It is true that the ignition in these later vettes are pricey and we tend to dread repairing them. They certainly are no where near as easy or inexpensive to repair/replace as the old one in say...your 80 camaro.. but on the other hand they tend to last a great deal longer. Enjoy what youve got ..and dont worry about it. And when that problem does accure be ready to do it all...wires,pump,opti,coolant,ect... Thats just one mans opinion........Dave
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by 94vette
1) Its expensive (around $300 at cost)
2) Usually have to replace the water pump, too ($150 at cost)
3) Pain in the *** location to get to.
4) Heck of alot of effort involved just to reach it (drain coolant, pull water pump, pull plug wires, etc.)
5) Every minute you are working on it, you are cursing the GM engineers who designed it and located it on the engine
2) Usually have to replace the water pump, too ($150 at cost)
3) Pain in the *** location to get to.
4) Heck of alot of effort involved just to reach it (drain coolant, pull water pump, pull plug wires, etc.)
5) Every minute you are working on it, you are cursing the GM engineers who designed it and located it on the engine
Well, to give you a better idea of why people complain so much about the "location" of the C4 OptiSpark, you might want to compare the above procedure to the older conventional design on C3's, with the distributor sitting on top, in plain view, at the rear of the intake manifold. If you wanted to replace Cap and Rotor...a 20 minute job!!! The Opti-Spark concept is quite awesome from a conceptual standpoint, with no lash to worry about with worn gears, very accurate optical sensors to control spark and fuel pulse duration, BUTTTTTTT... the implementation of the design sucks bigtime. Think about it, when your water pump goes bad and it starts leaking out of the weep hole, BLAM, it starts leaking onto the Opti_Spark.....water..antifreeze, and an ignition system don't play well together.... 
btw, doe's anyone know how C5 ditributor works??? Is it an Opti-Spark like on the C4, or something new?????
Last edited by MikeC4; Jan 16, 2005 at 08:27 PM.
Melting Slicks
Joined: Nov 2004
Posts: 2,348
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From: Belews Creek north carolina
St. Jude Donor '05
Originally Posted by JD'S WHITE 93
The c5 doesn't have the dreaded opti it has c.o.p. a seperate coil pack for each plug wire. Coil On Plug. 
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Pro
Joined: Jun 2004
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From: Santee Ca
Originally Posted by 94vette
1)
5) Every minute you are working on it, you are cursing the GM engineers who designed it and located it on the engine
5) Every minute you are working on it, you are cursing the GM engineers who designed it and located it on the engine
6) Every minute you spend working on it cuts into your driving time!
Safety Car
Joined: Apr 2003
Posts: 3,793
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From: VA
Originally Posted by rockindaves96
They certainly are no where near as easy or inexpensive to repair/replace as the old one in say...your 80 camaro.. but on the other hand they tend to last a great deal longer.
Safety Car
Joined: Apr 2003
Posts: 3,793
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From: VA
Originally Posted by bdvdvh7
of course it is a pain, and bad design, by the water pump, etc..
Originally Posted by bdvdvh7
but it is not like it cost thousands of dollars to repair.
Originally Posted by bdvdvh7
why is opti more of a nightmare than tires?
Tires actually are a bit of a nightmare on a vette, compared to most cars, but in context, when somebody asks "what should I look out for when shopping for a 92-96 vette" we don't have to tell him about tires, because any nincompoop can tell it's going to be expensive to replace those tires.
Originally Posted by bdvdvh7
if it goes, get a new one. like anything.
Melting Slicks
Joined: Aug 2003
Posts: 2,101
Likes: 0
From: Orange TX
Originally Posted by bdvdvh7
why when someone asks about a certain corvette the reply is always "be careful of the opti spark." can someone explain the big deal? of course it is a pain, and bad design, by the water pump, etc.. but it is not like it cost thousands of dollars to repair. we spend hundreds on tires, exhausts, brakes, and mods. why is opti more of a nightmare than tires? if it goes, get a new one. like anything. is there something i am missing... please help me understand. i have a 95, so i assume i have one too, and expect to replace it when it goes bad. thanks!!!
as long as you doit yourself, JMO 
Drifting
Joined: Aug 2003
Posts: 1,565
Likes: 2
From: somewhere between heaven and hell WI
Pffft you think thats bad, try owning a pair of black sheep of the C4.
But I think people use that as a warning of something to watch out for. How about the 4+3, same deal.
Funny part is these complaints or warnings are seem to be something nor non corvette owners b**ch about.
Go figure...
But I think people use that as a warning of something to watch out for. How about the 4+3, same deal.
Funny part is these complaints or warnings are seem to be something nor non corvette owners b**ch about.
Go figure...
Team Owner
Joined: Oct 2000
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From: 63.8% of all statistics are made up on the spot.
St. Jude Donor '08-'10
Originally Posted by MikeC4
: you might want to compare the above procedure to the older conventional design on C3's, with the distributor sitting on top,
The C4 L98 through 1991 has a distributor on top at the rear under a removable plate. Very easy to get to.