LT4 LT4 Corvette....the good the bad the ugly?????

[tntcorvette]

Hello,


I am looking into purchasing a LT4 Corvette. Was going with a ZR1 but it is more pratical to get a LT4. Anyway, once I sell my '85 i'll be looking into the LT4. Should be by the end of the year.

Anyay, I'de like to know all I can about the LT4 and its history. Any "common" problems they are prone to? Anything to look out for? Any recalls on the car? Common failure's? How about the ZF6 speed in the cars? I've heard that some fail???


Thanks!!!!!!!!!!

 

[Stinger !!]

Hello,


I am looking into purchasing a LT4 Corvette. Was going with a ZR1 but it is more pratical to get a LT4. Anyway, once I sell my '85 i'll be looking into the LT4. Should be by the end of the year.

Anyay, I'de like to know all I can about the LT4 and its history. Any "common" problems they are prone to? Anything to look out for? Any recalls on the car? Common failure's? How about the ZF6 speed in the cars? I've heard that some fail???


Thanks!!!!!!!!!!

These LT4's are dam near bullet proof!! Lots of them still running around with over 100,000 on the clock!

Zf trannies are just as good...problem free for the most part!

Much easier to get service and/or do service on these LT4's yourself compared to the ZR1's.

Good luck in your search!

 

[Notorious]

Since you're already a C4 owner, you're not in for any surprises. These are as good as they got. With proper care, all of the '95 and '96s are as reliable as any high performance car on the road. And pretty damned good among cars in general.

 

[Vettelt193]

Hello,


I am looking into purchasing a LT4 Corvette. Was going with a ZR1 but it is more pratical to get a LT4. Anyway, once I sell my '85 i'll be looking into the LT4. Should be by the end of the year.

Anyay, I'de like to know all I can about the LT4 and its history. Any "common" problems they are prone to? Anything to look out for? Any recalls on the car? Common failure's? How about the ZF6 speed in the cars? I've heard that some fail???


Thanks!!!!!!!!!!

The synthetic oil caused many leaks on the LT1 and LT4 cars. (not really a big deal though)

The ZF tranny was awesome through 1993; in 1994 they changed the design to make it quieter and they aren't quite as strong... you may have a problem with the tranny if you beat on it.

other than that, the problems are more C4 specific than LT4 specific... I don't think anyone would disagree that 1996 was the best year of the C4.

 

[stearnman]

The biggest problem with most/all LTx cars in general was/is the optispark. I'm sure you've heard of this issue. More than likely, the optispark on the LT4 that you will be purchasing would have been replaced/upgraded to the newer version over the original...usually depends on the milage of the car.

So, ask about the optispark whether it was replaced or not. (Not that it's bad to have the original optispark, just be ready to get is replaced if needed.)

More people can fill you in on the optispark issues.

Good luck and good LT4 hunting!!

 

[CAJUN C4]

The synthetic oil caused many leaks on the LT1 and LT4 cars. (not really a big deal though)

The ZF tranny was awesome through 1993; in 1994 they changed the design to make it quieter and they aren't quite as strong... you may have a problem with the tranny if you beat on it.

other than that, the problems are more C4 specific than LT4 specific... I don't think anyone would disagree that 1996 was the best year of the C4.

I wonder why Synthetic Oil could cause a leak?

 

[stearnman]

I wonder why Synthetic Oil could cause a leak?

I believe this to be the old battle between the usage of conventional oils for long periods of time by a previous owners and the eventually going back to synthetic oil by the current owners.

The gist of this leaking happening comes from deposits/slug biuld up on gaskets and other "sealed seem" areas between parts. Synthetics tend to help disolve build-up in these areas "causing" a leak...which in fact was leaky to begin with but was just "plugged" for the longest time.

Others here have better insight to this than I do...

 

[6 Shooter]

Most memories of my LT4 were Sweet, she ran Strong and handled Great with the Z51 suspension.

Here's a list of things I had problems with . . .

1. Replaced 1 LTPS (Low Tire Pressure Sensor)
2. Replaced water pump
3. Replaced drivers door hinge
4. Repaired electronic temp control this was the worst!
5. Replaced drivers seat track

Later . . . . . .
6 Shooter

 

[B17Crew]

tnt,
My LT4 is by far the best C4 I’ve owned -- the C4 had evolved nicely by ’96.

I think with these cars, once you go through and erase any of the issues a used LT4 will have, you will find it to be a reliable car. Since I “debugged” the common late model C4 issues, I have not had one problem with my LT4.

Below are problems that were taken care of under warranty.

The opti has been mentioned, although I’d like to point out I have no issues with it at 51,000 miles. The ’95 and ’96s have the vented opti, the original optis (’92 to ’94) were less reliable.

Waterpump was replaced under warranty.

The weather strip is a weak point unless religiously taken care of.

At some point, you will more than likely experience an engine leak. But once sealed properly, it should last a long time. No leaks at all on mine since 1998 when I had the intake manifold gasket replaced under warranty.

The ZF tranny has performed flawlessly.

Driver seat motor went on me in ’98 (warranty claim).

Steering column was “loose”, attributed to the original owner using the steering wheel to pull himself up and out of the car (warranty claim).

Overall, it’s been a great car, just needed to get things sorted out. The LT4 is a strong engine, I’m starting to believe the rumor that they were underrated by GM. I've run 13.2 @ 107, this is with a full tank of gas. Only modification is a K&N air filter.

Happy Hunting!

B17Crew

 

[Vettelt193]

I wonder why Synthetic Oil could cause a leak?

the particles in synthetic are consistent in size... in conventional oil, the particles range in size.

So in basic terms, regular oil has big particles, small particles, and particles in the middle. The 'big' ones tend to plug tiny holes in seals, so your car may start to leak, but will only leak until a big particle gets stuck in the hole... with synthetic, if the hole is big enough, oil will seep out forever.

This is why the oil leaking issue is not really a big problem... if they leak, it tends to be a minor seep, which won't even result in a noticable loss of oil between oil changes

 

[froggy47]

60k miles

No leaks on mine synthetic oil in engine & p/s, dino in tranny, rear.

 

[CAJUN C4]

60k miles

No leaks on mine synthetic oil in engine & p/s, dino in tranny, rear.

Froggy

What's dino ?

 

[froggy47]

Dinosaur oil is what some people call non synthetic oil. Comes out of the ground instead of the chem labs.

Sorry for the abbrev.

 

[CAJUN C4]

Dinosaur oil is what some people call non synthetic oil. Comes out of the ground instead of the chem labs.

No Please...I've heard that before...My mind was somewhere else.

Thanx

 

[Skyguy007]

My '96 GS has 80,000+ miles with a few problems, but nothing that has been overwhelming. I replaced the water pump at about 75,000 miles and put in an aftermarket Optispark (Dynaspark) at the same time, since the front of the engine was exposed.

I've replaced the clutch this year. Most of my reading about ZF 6-speed problems indicates that the vast majority of transmission failures happen because poor clutch maintenance causes the synchros to wear out. Keep the clutch fluid level up and replace the clutch when it's worn out and the tranny should be OK.

Althoug it's not an egnine issue, I would also heartily recommend the R-D Racing camber bar, which connects the upper frame horns at the front a-frame. I couldn't believe how this fairly simple installation improved the Vette's handling - super tight on turns and no more bump feedback through the steering wheel.

 

[tntcorvette]

I am looking at a collector Edition LT4 or a black LT4 as my primary choices.

Thanks for the great info everyone!!

 

[Nick S]

I was surfing through cars.com today and found this:

http://www.cars.com/go/search/detail.jsp?tracktype=usedcc&searchType=21&paId=132109047&pageNumber=0&numResultsPerPage=50&largeNumResultsPerPage=1500&sortorder=descending&sortfield=YEAR+descending%2CPRICE+descending&certifiedOnly=false&recnum=73&leadExists=true&criteria=K-%7CE-%7CM-_9_%7CD-_86_%7CN-N%7CR-30%7CI-1%7CP-YEAR+descending%2CPRICE+descending%7CQ-descending%7CZ-20170&aff=national

It looks like a black LT4 Corvette with 68,780 miles. They are asking $16,777.

Nick

 

[93Polo]

The Ltx car are known to leak oil at the back of the intake manifold which isn't a big deal.

The opti spark IMHO gets a bad rap. Just don't soak them in water. I've had 3, 1st 94 Z28 bought at 26k miles up to ~80k miles not a prob., 93 Vette bought at 34k miles and just over 100k the water pump went and took out the opti., and my parents 96 Impalla SS owned since new rolling up on 90k no probs knock on wood.

Also if you keep Mobil1 or another good synthetic in it, the motors last a long time. My 93 had the intake manifold leak fixed about the time the opti went out so ~100k miles and the lifter valley looked like a 30k mile motor. I changed the oil around every 5k not every 3k like some of the more obsessive owners.

 

[STREAK]

LT4 Hunting

My 96 LT4 has 17,000 miles and I have recently replaced the water pump, valve cover gaskets and front main seals. I have to believe that the failure was in part due to the lack of use. (low mileage) I've had a few electrical problems as well, but nothing that is serious.

The CE or the GS are lions in a sheep skin. Both will haul tail!

 

[6 Shooter]

The CE or the GS are lions in a sheep skin. Both will haul tail!

. . . any 96 LT4 will kick azz !

BTW - Welcome to the

Later . . . . . .
6 Shooter