billschroeder5842

Greeting from C3 land!

Please help point me in the right direction as I'm strongly considering a C4. I love my 82 C3 but the C4s have always caught my eye but I really don't know anything about them.

So, as a Vette lover but a C4 newbee, can I get opinions on what to look for, what years are "best" and any "known" issues I need to be on the look out for?

I'm looking for "A" level reliability, B+ performance on a straight line and ease of tinkering/fixing problems. I'm not looking for exotic "one of a kind" limited edition garage queens but a drivers car- I plan on making this a "mostly" daily driver.

Thanks for your thoughts!!

JimLentz

I just bought a '92 after owning a 1977. Try to find a later LT1 or LT4, 95 or 96. One of the potential problem areas is the optispark. The later cars have the vented optispark which is more reliable. A PO converted my '92 to a MSD vented model. Fixing these cars is different than a C3, as an example I recently had an ECM issue that required pulling codes, which is actually fairly simple. The issue ended up being cold solder joints in the ECM that I sent it out to be repaired. The 92-93 ECMs are getting hard to find. Much like for a C3 find a lower mileage one and/or one that has been well maintained. A C4 can make a nice driver car and my 6 speed LT1 does well on the highway for fuel economy.

THE 383 admiral

the 92 - 93 LT1 is a speed density batch fire ECM system. with a prom carrier eprom chip.

94 - 95 PCM's are VERY hard to find as well or way over priced. this system is sequential. and more precise. tuning this PCM could be done directly if desired.

the 96 OBD2 LT1 OR LT4 is a nice system.

The LT1 Opti weakness. is the cap & rotor no matter what year. the 95 - 96 vacuum vent does help. the vulnerable water build up. the other problem can be traditional build up within the high voltage spark creating build up. taking out the Opti wheel or high / low "eye" trying to find a Genuine GM Opti replacement. is very limited.

Patsgarage

Just to confuse you even more.......I would avoid the LT1 altogether, as all out performance does not seem to be what you are looking for. Any C4 will be much faster/better handling than your 82, but I would look for an 87-91 with the L98, if you are looking for a stick go with the 89-91 6MN. 90-91 had updated interiors that replaced the (sometimes) troublesome Atari dash, but the fixes are well known by know. The market is all over the place on these cars, but cheap ones normally wind up costing more than a clean one in the long run. Don't be scared by high mileage ones, these cars can go a long time.

95tealconvert

best advice I can share is check out a few L98's and LT1's etc. to find out what fits you best. As in most older cars condition and history is what really matters. Do your self a big favor and check a few out and see what is your best fit.

Many like the older interiors and many like the newer. Very happy with our '95 with the sport seats and dual air bags etc. GM kept putting money into the C4 over the years so general rule is later is more refined but that does not mean best fit so check out some before you buy one. I went to a Corvette show and checked out many C4's at one time.

BLUDICE

I had a '78 a couple years ago - traded it - then last week traded for a '94 - in '04 had a '03 - - like the '94 - it reminds me a lot of the '03 we had. Sure has a lot of computerized crap on them - not an issues on the '78 and the '82 don't have near as much - had fun searching.

cv67

Corvette remember?


Like any other car get the best maintained one you can make sure the electronics work le tit get good and warm. Plenty of low mile well maintained cars that can be had for what a late C3 goes for
Dont buy a fixer no matter how cheap it is if you arent familiar with them.
Paying a wrench can hurt. $$
From time to time youll see some real nice ones with 60k or less for well under 10k that need nothing or next to it.

hcbph

Personally I'd say start making your list of things you have to have, nice to have and couldn't live with even if delivered by a naked beauty.
Next would start making a list of cars that qualify against your list. Next I'd start looking up what problems people have had with that combo.
Things like the optispark have already been mentioned. Thing like the DM flywheel on the ZF transmission. Early ones had a different wheel offset than later ones. Early vs later dash - both can be fixed if needed. ABS repairs are like unobtanium - unobtainable. All but the 96 I think are OBDI.

Once you're hear then see about driving a few so see what you think and are they up to your expectations.

I made my list and 3 years ago I found my 86 convertible. It's probably 80-90% of my desires, but I'm picky I'm told. As far as a daily driver, the newest C4 is 20 years and the oldest is over 30, so that's a question for you.

1993C4LT1

Cusinartvet, Corvettes are reliable. I've been around Vettes since I was old enough to ride passenger in one. OP, don't let all these opti stories scare you. LT1 pull much nicer up top than l98's. I've got my 93 for sale. This car needs A&B pillar weather stripping and a new radio to be perfect. How much are you looking to spend?

woodstockdrifter

I see these threads often. Everyone likes to reply but there should be a sticky like a guide.

zrc3john

Look for a high mileage ZR1.....I'm guessing you don't want to spend upwards of 20k........There are a few examples of ZR-1s going for 13-14K...You may even get one with headers and exhaust.....Port the plenum and I/Hs and your close to 430 horsepower....

pologreen1

I agree, it should be a sticky of info on codes and models like viper forums,


'84 is cfi= 205 hp not many supporting mods
'84 4+3 od button is on dash not shifter like later
'86 late went to aluminum heads
'85-91 tpi intake 230-245hp
'early tpi had cold star injector
'92-'96 lt1
'96 lt4 option
'89-'96 zf6 6spd trans (early models black tag straight cut gears more raw)
'92?+ ? blue tag trans weaker, quieter
'84-'89 same interior "Atari dash"
'90-'96 same basic interior design
'95-'96 wider seats
'91-'96 newer body style
'84-'90 round tail lights
'91 square tail lights
'84-'87 weaker and different suspension mounts
'88+ auto trans was strengthened
'84-'87 36mm wheel offset
'88-'96 50mm wheel off set
'88-'96 larger brake options (j55)
'84-'85 non ABS. 86+ ABS
'84-'87 =16" wheels
'88+ 17" wheels
'90-'93 only years of speed density computer
-earliest models of z51 were almost racing suspension later got softer
-cloth seats/manual windows are rare ordered options
-auto= 2.59-3.07 gears
-6speed= rare 3.33 -common 3.42 gears
RPO build codes found in center console or trunk compartment

'90-'95 zr1 early ones only 375hp later 405hp
zr1 - 17x11" rear wheels

'96 Grand sport 1,000 made
-lt4 equipped
GS - 17x11" rear wheels on coupes

'96 silver collectors edition is lt4 if auto lt1

Callaway is a different thing and many options and things happened through the years, that will take research if you get interested in one.

Tons more of deeper info / options / codes out there, but this might help you decide what kind of driving experience you can be offered with a c4.

SJW

I recommend that you shop for the latest-model-year C4 you can find that is in excellent condition. These cars were refined and improved every year they were built. You'll spend more to fix what's wrong with one than you'd have spent to buy one that's in great condition. Educate yourself before you buy, and shop carefully. These cars can be a joy to own and drive, or they can be a money pit and a nightmare to own. It all depends upon the specimen you select.

As a beginning guide, here is a list I generated when I was shopping for a C4. It does not include anything related to the ZR1, because I wasn’t in the market for a ZR1. It includes the items that I considered to be notable changes as the C4 evolved during its life cycle.

C4 Corvette Evolutionary Highlights:

1983: C4 was deemed not ready for delivery. No 1983 model year Corvettes sold to the public.

1984: C4 sales begin. It is a completely redesigned car, but used the Crossfire (throttle-body) Injected engine that appeared in 1982. Suspension in these cars is stiff, makes for a harsh ride.

1985: L98 was introduced as the new engine (thru 1991). Rear axle on manual transmission cars became Dana 44 (thru 1996). Dana 36 axle used on automatic transmission cars.

1986: Convertible re-introduced (all were Pace Car replicas). ABS became standard. VATS (Vehicle Anti-Theft System) introduced. All convertibles and late coupes had aluminum heads

1987: Roller lifters added to engines.

1988: Improved flow-thru ventilation in coupes. New dual-piston front brakes. E-brake used discs rather than separate small drums. 35th anniversary edition offered (coupe only), white with black roof bow & white leather seats (2050 units sold).

1989: ZF six-speed was new manual transmission.

1990: Improvements to ABS and yaw control. Radiator improved. Instrument panel returned to analog except speedometer and fuel gauge. Driver’s side airbag and passenger's side glovebox were added.

1991: Rear exterior, nose, gill vent panels were restyled. Power steering cooler became standard

1992: LT1 was introduced as standard engine (300 HP). Traction control became standard. Weatherstrips were improved, Insulation was added to the doors and transmission tunnel to reduce road noise

1993: Changes made to LT1 to cut engine noise (torque was also increased slightly). PKE introduced. 40th anniversary edition option for coupes and convertibles (all were ruby red exterior and interior).

1994: Sequential fuel injection and more powerful ignition introduced. Passenger’s airbag was added (glovebox deleted). All seats are leather and were redesigned with significant changes to side bolsters. Run-flat tires were optional. A glass rear window with built-in defogger debuted on convertibles (plastic windows suck!). Air conditioners were charged with R134A refrigerant. Electronic controls added to automatic transmissions. PCM uses flash memory rather than EPROM. Some (but not all) OBD-2 functionality was implemented.

1995: Indy Pace Car replica was convertible only with dark purple metallic and white (527 units sold), stronger French stitching used on sport seats, drip tube added to A-pillar weatherstrip to improve water sealing, fuel injectors revised to cut dripping after shutdown, connecting rods changed to powdered metal for strength and weight uniformity, larger J55 brakes used on earlier Z07 and ZR1 became standard, wiper arms changed to improve performance, newest ABS and ASR standard, gill vent panels restyled, actively-vented Optispark distributor on LT1 was an improvement over previous passively-vented units.

1996: LT4 engine was installed on all 6-speed cars, LT1 engine was the engine for cars with automatics. Automatic transmissions were improved (clutches, bands, torque converter), Grand Sport option offered (Admiral blue paint with stripes, LT4), Collector Edition available (silver paint only), new On Board Diagnostics (OBD-2), LT1 and LT4 had new throttle body.

Happy hunting!

Live well,

SJW

Larrye

Good info here, been very happy with my early L98 C4. Personally, I like the 1985 model, first year L98, non-ABS, no high mount stop lamp. Not a monster but a very basic, quick, fun car to tinker with and drive. I think the later C4's are great as well, and would like to add an end of production model to the garage soon.

Mikemils

Bill I just joined corvette forum and currently have a real nice 1989 c4 for sale (as seen in profile pic). I put c5 zo6 wheels on it and the stock wheels go with it too both with good tread (stock wheels have new tires). It also has new carpet. Everything in it works great. It is currently all stock and tagged antique in my state. The car is still quick and with a few minor modifications you can really wake the l98's up. I am selling because I plan on building an old hot rod. Asking 8200. It has around 45000 miles last I looked. Garage kept under dust cover with battery tender.

ghoastrider1

C-3, c-4, night and day..but then same with all the c- model changes. you will find the 4s much quicker than the late model 3s. The low end on these things means don't floor it when making a sharp turn. If you do, you will be looking at where you just came from. Now thebad parts..lol. aint none. It seems like many GM cars from the 80s, yop coat/clear coat likes to peel.Depending on your age and fitness, you may not like getting in and out of the c-4s. As stated b4, get the best one you can afford. I bought a 86 fixer upper, a few years ago..still needs lots, but love it. Just make sure the dash work proper, the windows work and the heat/ac work. Oh, and the headlights..hundred bucks a pop there. Make sure the targa top (if see thru) isn't cracked. As in all vettes since the 1963 coupe , check and make sure it doesnt leak. BTW, doesn't hurt to live in c3 and c4 land. Oh, you may be happier with an auto rather than a standerd. The overdrive feature in the auto is great and fuel milage will be at least in the 20s. Welcome to the c-4 forum neighborhood.

zrc3john

How about keeping the C-3 and putting in a 383 Stroker....Very popular choice for C-3 owners..

Buccaneer

IMO any Opti Spark motor is a bad choice, but ANY C4 with a LS3 motor is just badass...jus sayin'. Good luck if you make the move.

HAD2HAV2

Back in 1995, I was making the move from a C3 to a 88 C4. Like others have posted, 88+,until the LT1 came out, had the most updated GM parts for the L98 engine and the A4.

H P Bushrod

My first C4 was a '85. Had lots of fun with it. My 2nd was a '93 Ruby coupe. Never had a problem with the Opti and when I traded it, It still ran like it was new. I'm on my third now...A '88 35th Anniversary coupe (#1405). She just turned 51,000 miles and she'll definitely get driven. To the OP: Check out different C4's and see what you like. Whatever you do, don't buy a fixer-upper C4. These cars will get in your wallet quick, Best to lay out some extra cash for a good one you can enjoy immediately and take cross country if you wanted to.