Thanks in advance. I'm trying to determine what particular trouble spots I should be looking for in the C4 model. I own a C3 now and am well versed in their particulars, but my wife has taken a liking to a 1989 convertible and the car has very low miles and appears all original. I have not run the VIN yet, and the seller indicates the car is original and well maintained and the photos show it. What particular areas should a new C4 buyer look for? I have read that the opti spark distributor and water pump in the C4 are issues...any help is appreciated.

 

The good news is the 89 didn't have the opti, it has the HEI computer controlled distributor. I am still somewhat new to the vette forum and I have a 89. The heater core on all C4's is apita to remove so check for leaks and dampness on floor. Look at how car sits, make sure it has that corvette stance, and does not lean or sag in the rear. I am sure others will chime in with better info.

 

If it were me, I'd take it to a shop for a Pre Delivery Inspection. I would want to check the condition of the differential oil and the trans pan to see if there is debris. If the trans oil is too new, be suspicious. Have them scan it for performance data to see if the sensors are within spec readings. Do a compression and leakdown test.

 

I got my 89 convertible about two years ago with 67k on it. Looks as if it had sat for quite some time. Performed basic maintenance, all fluids plugs wires etc. Exhaust is rusted so I patched till I can afford to replace. Steering rack has a slight leak. Just replaced tires and had it aligned and it drives totally different. Stills needs brakes, coolant recharge and I changed the heater control module. The blend door may be stuck as it always blows hot air. Need to replace two bulbs in the dash and replace two speaker amps. Rubber seals could use replacing. Replaced the soft top as the plastic window was toast and picked up a hard top that made a huge difference in usability. It is a work in progress but I drive it several times a week and don't worry too much about it leaving me on the side of the road.

 

think of it as a 30 yr old Chevy with 4 wheel disc brakes and IRS. Things touched on, add the u-joints in the rear and drive shaft. Do a compression check and a cooling system test. Some have had a blown head gasket between the #6 & 8 cylinder on the L98 engines. Be sure to check the hubs for play. Rest pretty much aligns with any almost 30 year old car (paint and body, tires, ball joints, tie rods, bushings, fluids, compression, paint, interior, etc.).

Most parts are available given enough time and looking while others are either used or unobtainable. Things like ABS, no one rebuilds and can't be found new. Same thing with things like abs sensors.

Good luck, hope it's the car you want. They're good, you'll like them.

 

Enjoy your new C4..!!

Besides the regular maintenance items, it may be a good idea to check and keep an eye on these for possible future repairs:

MAF
Headlight motors/gears/bearings
Steering rack and hoses associated with it. (all hoses as well)
Of course any and every leak or possible old gaskets, replace whenever convenient and reasonable. My gaskets seemed to all go at the same couple year timeframe.

28-30 years is a long time for original parts, even replacement parts could be 15+ years old etc..! ha

Good luck.!

(some good sources for parts include, Summit Racing, Ecklers, Mid America, Amazon, Ebay, and surprisingly local auto parts stores can get more Vette parts then you might think...)

 

If the injectors are original expect to replace them. They weren't designed to handle ethanol fuel and it will eat them up. Talk to Jon at FIC. Forget goodwrench.

 

I'd go to rebuild units from FIC. Old ones are like you said if they are Multecs or have built up residue

 

Current owner has responded with some work he has done during his ownership:

Brake cable in '03
Fuel pump/strainer/injectors in '09
alternator in '11
parts for headlights in '12
top seals in '14
instrument cluster in '15
battery/valve cover gaskets/distributor base gasket in '16

Sounds kind of promising

 

Automatic or manual transmission? I had a '77 and now have a '92 and the handling is so much better on the C4's IMO.

 

With what? NOS Multec? Bosch 3?

What parts?

Rebuilt or what? Who did it?

 

Newer tends to perform better. Older is for people trapped in that era and need the nostalgia.

 

I definitely agree, I have owned a C3 and have driven in many, especially back in the 80's and they are great and handle well, but the C4's were at a whole different level when they came out and I still feel my "88" handles awesome, its glued to the road.! : )

I have been in 1-2 newer generations, but not a new C7 yet, I can't imagine how well they handle or how well they do everything for that matter.!!

 

Sometimes the brakes tend to be decent but not great and the fuel injectors seem to need replacement (possibly due to alcohol in fuel today) but it sounds like those have been replaced. There are lots of threads about less than optimum braking. Mine isn't great. i dont have an answer with my 89 but to me it's probably the best year of the C4. I've had plenty of C3's too and love them also. What you will enjoy most with the C4 is that your feet and legs wont burn up in the summertime.

 

For autocrossing, probably brakes need to be upgraded but if not, I really don't see them as sub-par. Fuel injectors, sure. They have been replaced but with what?

If you are feeling that way, why not upgrade them? Why is the 89 the best year? L98 goes all the way to 91 with 90-91 being speed density. If you don't need larger window of compensation from the MAF, not sure if either way would be better assuming properly tuned for the application. 85 and 86 were iron head. I think 87 and up were aluminum head so not sure. 92 would be the Opti but supposedly there is a fix for that. That said, the L98 would definitely be harder to find tuners than the later LS motors.

Do the later generations have issues with heat? IDK. Just curious.

 

89 being the best C4 year is subjective. I guess it being the newest with the digital dash (part of the original C4 Design and distinctive). Many believe the MAF is superior to the MAP although might not be as reliable. I doubt later years or generations have problems with heat but he's a C3 Owner. I'm not sure what year but 68-75 or 6 were super hot on the legs before the metal floor. I've had two 72 conv and a 68 conv 327/350 and my first C4 was a 84 back in 1987. Anyhow, in the summertime an earlier C3 gets so hot on the legs is almost unbearable, but hey I'd like to have another one. I like all years and favorites are subjective. It seems reading others comments that an 89 and a 96 are often favorite C4 years. I actually have a fondness for 84's but I guess thats nostalgia. My brakes are questionable, but if I energize my ABS with some panic stops its fine for a while. I just read many others that constantly complain of the brakes in C4's. My two 84's were great from memory, my 89 not so much. Maybe it's a fix I still haven't stumbled on. I was just trying to help the guy out with my take on the 89. I used to go fast, now I'm more into the nostalgia I guess (cheaper than speeding tix) although I still like to go fast. My favorite years are 67, 68, 72, 82, 84, 89, 96 each for different reasons. Just an opinion, not discounting others likes or preferences. Carry on.

 

Don't want to get to off track from the original posters question, but it is fun to talk about favorites....I had a 1969 Convertible 350/350 4 speed and now have a 1988 Coupe 4+3 so they are of course both my favorites, but others I have not owned would have to be the old fuelies, the 1965/66/67 and last, but not least the 63 split. I also liked the 80/81/82 as well. If I remember, the 1980 was supposed to be a good year to have, but it is certainly all subjective. Of course the post 1990 ZR1's and Z06's are great too, obviously.!!

If I remember, I think the 89's were looked upon favorably back then because it was the first year C4 without the not too popular 4+3. (the 4+3 never bothered me though, I actually like it...)

Basically I never met a Vette I did not like.!! lol

 

I pulled the trigger. Thanks in part to everyone's input (appreciated!). I came to the decision that the car couldn't be so catastrophically bad that I could ignore the price. Turns out the car is in as good shape as the owner said. Everything works! Headlights were rebuilt with brass gears, injectors look new (I don't know the brand), car runs cool. It operates at around 190 and while running and idle/not moving for a number of minutes it would go up to as high as 228 before the fan kicked on and started pulling temps back down. Back on the road, it dropped back down to 190ish. I could smell coolant with the hood up and the engine running and there is a definite "bearing" squeal. I'm thinking maybe the water pump bearing is on it's last legs and the seals may have worn as there is some small amount of moisture I could see on the running gear on the passenger side toward the front. A new water pump may resolve all those issues? A small price to pay in my opinion. Oil was clean and coolant temps and oil pressure were in spec so I don't think it's anything more serious than that. Top is new, interior is factory fresh, body good but the hood is slightly misaligned on the passenger side with a larger door gap at the top. I have to the the hood has been off in the past and there is some evidence of paint work on the rear deck where it meets the bumper. Having said all that, it drives true, but as other posters mentioned, brakes are "weak". In the end, if I put on new pads/flush brake fluid and install a new water pump, I'm happy as a pig in...

Sorry for the pics, I'm working through being a newbie and trying to figure out how to insert photos without them being turned/rotated. Until then, you'll have to crane your neck a bit.

 

Nice, good luck with it.!!

Great colors for a convertible, the original white/red(maroonish) like back in 1953.! : )

Question though, how do you drive it upside down like that..???? HA
(ps, I have no idea how to post a picture..)

 

Congratulations. Always a special day when you bring one home. I sure like my 89 Conv. I love the C3's still but the underhood access you get with the clamshell hood is something easy to take from granted. Enjoy!