I'm curious if anyone has ever had an issue with their trip odometer reading a really out of whack number than it should be? My 96' LT-4 has 33.5K on the odometer, but the trip odometer in standard reads over 127,000 miles, but if you switch it to metric it reads the correct distance in km of what it was since it was reset, something like 80.7km. Anyone had an experience like this?

 

never! strange[8D]

 

Thanks for the reply. I doubted anyone has had a similar issue.

After talking on the phone today to the local Corvette expert who's been servicing only Vettes for 30 years, he thinks it's a glitch created by a dead battery and nothing more. I'll find out for sure Thursday when he looks at it. I just bought it 3 weeks ago from the second owner. I've bought 3 older Mustangs and know cars enough not to get taken. This is my first Vette and from what I looked at on the market before I found this one, believe me, it looks like a 33K car inside and out, not a 133K car. So I'm hoping it's the glitch, if it's not, needless to say there will be a problem.

 

ya. but if there is a problem it can be fixed..let us no your out come

 

It is more than likely an error in the logic on the circuit board of the IP. Might have to get a rebuilt one, sorry to say. [8D]

 

Update:

The weather was finally good enough for me to take my car to the local Vette expert. (Expert defined as: only worked on Corvettes for the past 30+ years, he's a mechanical engineer by education, studied the operated systems used in Corvettes an ex-Naval Academy graduate and Vietnam Veteran combat pilot and has discussed the issues mentioned in this text the engineers on the Corvette team that developed the LT series motors.) In otherwords, not a recently graduated GM tech telling me stories.

OK, with that said...He looked the car over and confirmed that my odometer was correct 33,700k and that the 127,500k reading on my trip odometer was false and likely caused by me running the battery down then charging it back up with a charger. He checked out key areas of the car to confirm that the wear and tear wasn't there and the car was legit. Not to mention the condition of my car, just looking at it you know it's not a 133k car. Needless to say I'm sleeping much better now!

However, learned that there are two issues to look at on LT-1 and LT-4 engines that I thought I'd pass on to any other new or perspective Corvette owners like myself.

First is the intake gasket, they tend leak very early in the engine's life, look for the leak on the rear of the intake manifold near the firewall. There will be a greasy film or look dirty around this area.

The second issue is the GM factory water pumps on these engines used poorly designed impeller bearings (double row of ball bearings). The reason it's a bad design is the stress that the impeller shaft puts on the ball bearings and the rate at which the ball bearings have to spin (which is approximately 4X's the rate of the shaft or 16,000 rpm's), wears them out quickly. Once the bearings start to wear out they cause movement in the impeller shaft and failure of the water pump. GM reports a 100% failure on these water pumps and a service life of 24k to 45k miles. He said the best way to tell if it's leaking is to look at the hood, if there is a horizontal streak on the hood, it likely from the coolant hitting the belt and it flipping it all over the hood. Otherwise you'll need a small mirror to check around the water pump to see if it's started leaking. Since the distributor sits under the waterpump, you'll want to make sure you keep an eye on it so it doesn't leak on your distributor which can cause more issues.

My tech replaces the GM unit with an aftermarket pump that utilizes roller bearings that won't wear out. So if your LT-1 or LT-4 water pump fails, don't replace it with another GM unit, get a unit with "roller bearings".

From what I've learned the intake manifold gasket leak and water pump were the two most common "major" issues with the LT-1 and LT-4's motors. Otherwise they are rock solid engines.

Just some info I thought I'd pass on in case others have similar issues.

 

Interesting comment about the water pumps.
Do you have any particular brand in mind that uses a roller bearing?

Thanks,
Doug Leithauser

 

I'll find out from my tech and let you know the brand he uses.

 

Regarding the aftermarket waterpump and the roller bearing vs. ball bearing issue, per my research "GMB" manufactures one of the best units for the LT-1 & LT-4 motors, it is brand new, not remanufactured and has a full roller bearing impeller shaft. You can see a cut away of their unit on their website showing the bearing design and unit construction. GMB is the OE manufacturer for many automoblie companies, GM's not included. They private lable for autoparts stores, you can get a GMB unit at Autozone under their "Duralast" brand, model # DWP-9001 for $132.99. I've also learned that you shouldn't install a "remanufactured" water pump ever, if you're spending the money or puting the effort in yourself to replace the water pump, spend the extra $50.00 and put a new unit in no matter which brand you buy.

 

amen brother... buy brand new.. i agree 100 %