Hi guys. I am starting to look at some C4 corvettes and was wondering if any years were better than others due to mechanical or body issues. I have had a few C3's and know they can have bird cage issues, and other rust areas. Do the C4's have any usual problem areas of concern?

 

I would definitely shoot for getting a 1996 LT4 if you are going for a C4.

If your wallet permits it, the ZR-1 and Grand Sport are the best of the C4 generation for sure.

Any C4 base model that is 1992 or newer will have the LT-1 engine which will be 50 more HP than the old L-98.

The body and specs pretty much got better every year after 1990, I personally wouldn't want anything older than 1992 for the C4 gen. They were all pretty stout but after 1990 they had exterior & interior updates, engine updates and more for most models so I'd shoot for those.

I guess it depends on what you are wanting exactly.

 

And what I can afford. Thanks. This gives me a direction to look into. I was actually looking at some 94's.

 

I agree with above statement, I drove a few and it was clear to me the later models and upgrades were much nicer C4's. But It took me a while to find a good deal on a later C4. I would have preffered GS and I know I couln't afford a ZR1. But once I got this 94 with a manual 6spd LT1 I love it and I didn't feel like I overpaid, I felt like I got a steal or the better part of the deal. Thats when you know you got something. I would have bought an early C4 for the right price and still have lot of fun with it. I just didn't want to get into something I had to put more money in than its worth. Check the car out and what your getting for your money. I like all C4's but its all about what you put in and wana get out of it.

 

C4's have nothing of substance to rust .

 

You didn't mention your price. I personally like all C4s but prefer but prefer the styling of the later years. Like most Vettes the new ones tend to improve upon prior years in power, reliability, and build quality. If you can afford a 95 or 96 that would be your best bet in terms of reliability, power, and build quality. The LT engines which offer the best power for the generation (excluding LT5 ZR1), have one design flaw which is the distributor location (Optispark). I personally am running original Opti with 70K however others are apparently not as lucky. My biggest gripe with the Opti is that it requires a lot more work to replace than your typical distributor. Otherwise these cars are solid if you find one that hasn't been wrecked, neglected, or modded. I personally own an LT4, which I would recommend if you can find one at a reasonable price with decent mileage (I've found LT4s dont seem to come up for sale as often as other years). However, 95s are more available and a good choice as well. One last thing which I'm sure you've experienced with your C3 is pay a bit more for a car that is in good shape than a few grand less for a car that needs a lot of work. No C4s are likely to ever become serious collectables so just buy it if you like it and dont be concerned about resale.

 

The biggest problems are weather stripping, paint, interior condition.

The genII LTx engines are a short run, however they are all small block chevy's.
Clamshell hood makes them fairly easy to work on.
I can change plugs and wires on mine fairly easily. Had to take the Wife's 04 to the shop to have them finish, no way I could do the driver side plugs.

 

Here's a good one. http://forums.corvetteforum.com/c4s-...fx3-coupe.html

 

I loved my C3's, even with their potential problems. Can't afford them anymore. So that's why I am looking to C4's. I want a convertible, so I'm thinking 90-94 will be my best shot. I am not looking for any more "projects". Just looking for a good driver that I can turn the key and drive. I am done doing rebuilds. Miles do not matter, and I am looking for good condition, doen's have to be great. I think I am being realistic with myself and my expectations.

 

What was the first year for the Optispark? What was the benefit of it. I heard that it can be a pain the work on.

 

The OptiSpark was the distributor on all the LT1 motors (92-96). They aren't that much of a pain unless they get wet. There are lots of noobie LT1 owners that decide their LT1 engine is dirty and they wash it with a pressure washer or garden hose. That's a big It's sure death for the Opti. A water pump failure that dumps coolant is also an Opti killer. The OptiSpark unit does not like getting wet.

As far as the C4's go, there were improvement made every year, so try to find the latest one you can for the money you have to spend. Sometimes there were engineering changes made in the middle of a model year and you will see some car years referred to as "early" or "late" The 86 is one example and the 93 is another.

ZR-1's are very affordable but it can be pricey to do engine work. A few years ago, GM sold off all of their extra LT5 motors and the aftermarket for engine parts can be limited. But they still are a great buy.

In any event, look at bunches of cars before you decide. Ask here about any specific thing you see on a car and you should get good answers. Also use the "Search" function in both C4 sections; could be that similar questions have been asked ans answered.

Once you get to where you are ready to buy, ask the seller if you can take the car to an independent auto repair shop for a Used Vehicle Inspection or "UVI". A shop will do a thorough inspection and give you a written report on needed repairs and estimated costs. Figure on $125 to $150 to have this done. Then you can use that info for final negotiations with the seller.

 

95 or 96 best condtion one you can afford.

 

So far I've owned an '86, '87, '88 and now a '96. Each had their advantages, but as mentioned the cars did seem to improve as the years went by. Here's a few things to consider.

The '86 and '87 were good cars, and the prices are very good right now. The '88 I had a couple years ago was under $5k for a very nice relatively low mile (87000 when I bought it) car. I sold it several months later for a nice profit and hadn't really done anything to it but drive it.

The early years (up to '88 or '89, I'd say) are probably the least expensive (obviously), but your'e also not getting as much by way of creature comfort or actual power. The '86 has about 235 horsepower, if I recall, and there is a distinct difference (felt in the seat of the pants) between say the '86 and the LT1 in the '96 model.

While I like both '86 and '88, in my mind the only reason to go for one is budget. If you can't get into the $10k plus range for an entry level "good" late run ('95 & '96) then the '86 to '88 models are good choices. You can get very nice car for well under $8k. A trailer queen with super low mileage will obviously cost much more.

I enjoyed both, so there no reason for me not to suggest them as good entry level or lower budget Corvettes. If you are choosing between an '86 & '87 then make sure to drive them. I hadn't realized that the '87 suspension was that much different, but after driving several when I was looking for my first C4 I did notice a difference that would suggest the '87 and up modeels were "improved." Some folks might not notice much of a difference, and if you're new to the breed then there's a good chance you are in that group. As I type this, though, I'm reminded that because someone tells you to watch out for one thing or another doesn't necessarily mean that the particular car is a bad choice. As I said, I liked both the '86 and '88 cars I owned, but there are subtle (and sometimes not so subtle) differences between the different models.

Some folks will tell you that quality control on the earlier models was not as good as in later years. I kind of noticed that as a trend for just about every generation. As an example, one of my favorite C3 models is the '68 (I love that removable rear window), but the "experts" will tell you that the quality control was bad for that model year. I don't mean that in a bad way, I mean that folks who know a whole lot more about these cars than I do will tell you this, but for me personally, I think every year has some quirks, so it's just figuring out which you can live with. I'd put up with some of the other down sides of the '68 if I could find the right one for the right price.

Let me jump to my '96 for some quick comparisons. My '96 is a very different car from my earlier C4s. The first thing that made a difference for me was the question of the LT1 versus the LT4.

As noted, the LT4 is the "prime" motor, and it will be the more expensive. A 96 Grand Sport or Collector's Edition are probably considered some of the top "investment" cars for the C4 models. Of course, if you are looking for an investment then cars may not be a good choice. For all around fun, though, the extra few horses in the GS and Collector's model might just be worth that few extra $$$.

Then again, if you have that kind of money you should probably be looking at the'93-'95 ZR1. A '93-'95 ZR1 has the Lotus motor (same basic L98 engine with 4-cam, 32-valve upgrade known as the LT5 motor). A very nice one will set you back $25k or more (unless you just find an amazing deal). And if you want something that is "collectible" then this is probably it. For me, though, I'd rather spend 1/2 that amount on a nice '96 LT4 or a very nice '96 LT1 ... then use the rest for trips and buying related goodies for the car.

Back to the LT4, something that I hadn't realized until I started doing more research is that while the LT4 is a more powerful motor, you can't get one with an automatic. I know, some guys won't own a Corvette if it ain't a stick, but those of us with a physical problem simply can't shift all the time. So the LT4 is a no-go if you don't want a manual tranny.

I also prefer the later models simply because they seem more refined. If you're like me and you like having a little more creature comfort then the late run cars are a good choice. That's one reason I love this '96, it is simply more comfortable (the seats are wider and they have a "deeper" padding). The interior is great, controls easy to manage, and the whole setup with electronic adjustable seats makes longer trips a lot better.

As you're finding, the difference in output between the earlier year ('86-'88 in my case) and the later year ('96) is fairly significant. We're talking about 65 horsepower going from 235 in the '86 model to 300 in the '96 LT1. If you do select the LT4 then you'll jump to 330 horses with standard equipment.

Hope some of this helps.

 

If there is one thing that an LT5 is NOT is a "basic L98 engine with a 4-cam 32 valve upgrade". The LT5 is a virtually all new engine that shares nothing but bore centers with the Chevy small block. If anything, the LT5 was the source of many innovations that led to the 97 on up LS series of motors (deep skirt blocks) and the improved power of the LT1/4 over the L98 (reverse cooling).

As for values, ZR-1s range from $45-50K for low mileage 95s to mid-lower teens for very high mileage 90s. $25K will net you a very nice 375HP (90-92) ZR-1, but it would take low 30s for the equivalent 405HP (93-95).

 

I recently picked up my 95 with 37K on it that has been a garage queen its whole life for $11.5. No real flaws to speak of and it had some mods I would have done, wheels, corsa A-mold replica wheels and a couple little things that saved me over $2G in expense on those. Good deals are out there. Most similar cars in my area were listed $2-3G more, just found a motivated seller at the right time. It needed a new ashtray lid and rear hatch weatherstripping, otherwise you'd swear it was new.

 

As most of the others have noted a 95 or 96 would be my preference.

i sold my 95 Z51 6 sp car in 1998 to buy a C5 Ragtop which I still have...

HOWEVER I always liked the C$ and new I would one day buy another...I limited my search to 2 Cars...The 96 Grand Sport and the 99 35th Anniv Coupe... because I always liked those 2 cars...

I picked up a 35th Editon and am still smiling

Bob G.
64 72 & 98 Ragtops, plus 76 79 and 88 Coupes in the garage

 

Mostly all the variations over the years have been discussed, but one thing not mentioned endemic to every c4 ever made was frame corrosion under the battery tray. Every car has a trace of it, but avoid a car that sat for years with a dead sulfated battery in it- that"s about it on theses cars- they did a good job on the frame and materials otherwise.

get a car with the vented opti (later ones), but earlier ones can be converted to the new part so it's not that big of deal. 1995 is my favorite year.

 

One other thing about 95 you still get OBD1 which I prefer as I just know it better. And also in IL no emissions testing for pre 1996 cars.

 

I like 95's real well. OBD2 is good but I like OBD1 better. Easier to tune, less o2 sensors etc. 1995-1996 were also the vented Optisparks which were magnitudes more reliable than the old non-vented Opti's.

 

The mantra is generally get the best one you can afford. I would make sure the water pump has been done recently (the biggest reason for opti failure on LT motors, not the opi itself), then you'll be less likely to have this happen to you. Having said that my car with it's 'new' water pump has started leaking from the pump 4 yrs later and not that many miles...
Get under it and look for leaks