Question: 1996 LT4 Water Pump - Who should I buy a replacement pump from? Should I Replace Good Opti?

[mcich7781]

My 1996 LT4 (40K Miles) water pump has started the fatal weep.

Where have LT1 / LT4 owners purchased their replacement Water Pumps from, and what luck have you had?
There are so many suppliers and everyone claims their's is the best.

My car still runs perfect and my Opti is working perfectly. Should I tear into the Opti while I am replacing the water pump?

Thanks,

MCC

 

[96gs917]

I replaced the water pump in my polo green LT4 twice, once @ 18k miles, replaced under warranty by the dealer with a factory
replacement, and a second time 4 years later @ 29k miles, replaced by another dealer with a factory GM water pump. Car now
has 39k miles. Both times the water pump leaked from the weep hole and spit anti-freeze on the belt, and then all over the front of
the engine, and under the hood. I never had to replace the Opti and the car runs great.

I think GM still sells the correct factory replacement but given my experience you may want to try an aftermarket.

Good luck.

 

[John Robinson]

First the opti if it is working should be left alone. I know that with the water pump off it is tempting to replace it. By 1996 GM had made modifications to the opti to vent it. Since you will have the water pump off it is a perfect time to replace the spark plugs and wires. The plugs are probably not that bad but the wires after all are 16 years old and just the exposure to heat and time will have an effect on on them.

 

[LT4man]

I agree totally with what John says. If you are having no issues with your ignition system, leave the Optispark Distributor alone. The Opti has to be the most maligned part ever commissioned by Chevrolet to be built.

I still have the original Optispark Distributor. Replaced the cap & rotor with an Accel at 95,000 miles. The screws which secure the rotor had loosened & were sitting in the base of the distributor. The rotor was still on the shaft & because of the design, could rotate a litttle but did not fall off. A slight high RPM miss led me to this.

As far as the water pumps. I recently replaced mine for only the second time in 131,000 miles. The first one failed at 70,000 & was replaced under the Dealers Assurance Company extended vehicle warranty. Saw some drips on my garage floor & the pump was replaced.

I believe all the pumps now are built in China. If you could find one which was built in the US, that could be your best option. I bought mine at AutoZone. Happy with the construction & the operation.

 

[gmjunkie]

First the opti if it is working should be left alone. I know that with the water pump off it is tempting to replace it. By 1996 GM had made modifications to the opti to vent it. Since you will have the water pump off it is a perfect time to replace the spark plugs and wires. The plugs are probably not that bad but the wires after all are 16 years old and just the exposure to heat and time will have an effect on on them.

I agree totally with what John says. If you are having no issues with your ignition system, leave the Optispark Distributor alone. The Opti has to be the most maligned part ever commissioned by Chevrolet to be built.

I still have the original Optispark Distributor. Replaced the cap & rotor with an Accel at 95,000 miles. The screws which secure the rotor had loosened & were sitting in the base of the distributor. The rotor was still on the shaft & because of the design, could rotate a litttle but did not fall off. A slight high RPM miss led me to this.

As far as the water pumps. I recently replaced mine for only the second time in 131,000 miles. The first one failed at 70,000 & was replaced under the Dealers Assurance Company extended vehicle warranty. Saw some drips on my garage floor & the pump was replaced.

I believe all the pumps now are built in China. If you could find one which was built in the US, that could be your best option. I bought mine at AutoZone. Happy with the construction & the operation.

 

[mcich7781]

Replacement LT4 Water Pump

I agree totally with what John says. If you are having no issues with your ignition system, leave the Optispark Distributor alone. The Opti has to be the most maligned part ever commissioned by Chevrolet to be built.

I still have the original Optispark Distributor. Replaced the cap & rotor with an Accel at 95,000 miles. The screws which secure the rotor had loosened & were sitting in the base of the distributor. The rotor was still on the shaft & because of the design, could rotate a litttle but did not fall off. A slight high RPM miss led me to this.

As far as the water pumps. I recently replaced mine for only the second time in 131,000 miles. The first one failed at 70,000 & was replaced under the Dealers Assurance Company extended vehicle warranty. Saw some drips on my garage floor & the pump was replaced.

I believe all the pumps now are built in China. If you could find one which was built in the US, that could be your best option. I bought mine at AutoZone. Happy with the construction & the operation.

I am going with the Auto Zone New Pump. (Best warranty and reasonable price)

I plan on adding the drip tubing to the weep hole modification I have seen on other LT1 Forums.

Opti will stay in place and will be bagged before any Water Pump Bolts are loosened. I will do the dark garage spark plug wire check with the plant mister and if ok I will leave them in place. If I see any corona I plan on getting the Red replacement wires from Ecklers. I want to keep my old ones as they are the numbered originals.

Thanks for all the feedback and advice.