When I purchased it and left it outside, the rainwater quickly found its way inside the rear hatch compartment. It turned out that this water leak is quite common on both the 280Z and 300ZX.

Unfortunately I wasted some money on trying to get this leak fixed before I looked into technical service bulletins. I figured since the hatch compartment was wet that the aging hatch seal must be the cause of the hatch water leak.

I purchased a new hatch gasket from the dealership and this cost me around $150. After replacing the hatch seal I anxiously waited for the next rainfall to come and go. To my disappointment after a hard rain the rear hatch compartment was again like a miniature swimming pool.

How to repair the 300ZX water leak

After my first attempt failed at repairing the hatch water leak I looked into technical service bulletins as well as performing an Internet search. Many Z owners had reported the same type of rain water leak. Find out more about Car Repair Bulletins here.

The technical service bulletin stated that the water was entering from the tail light assembly’s. The taillights on the 300ZX attach through the rear compartment wall. Water was dripping onto the threaded screws and traveling into the rear hatch compartment.

The fix was to completely seal the taillights assemblies and stop the water from reaching the threaded screws that entered the rear hatch compartment. The silicone sealing job did not look very neat but was very effective at stopping the water.

The good news was that when the hatch lid was closed there were no signs of silicone. So the messy silicone seal job was my dirty little secret and could not be seen by others checking out the overall beauty of my 300ZX.

Why you have to fix water leaks

Water collecting in the rear hatch compartment can be very destructive to the health of the overall automobile. Yes the main problem will be rust developing in the bottom of the hatch compartment. And trust me replacing the bottom of the hatch compartment is a lot more difficult than repairing a water leak.

Another destructive part about having water lying inside of the car is the increased humidity level inside the vehicle. This can greatly accelerate corrosion throughout the interior spaces of the automobile. Things like connectors and wiring harnesses will start to turn green and provide intermittent connections quickly. Also components such as control modules and relays can be negatively affected by a hatch full of water.

But one of the most destructive properties of an interior compartment full of water is the effect on the grounding locations. Vehicle system grounds can quickly become corroded in a humid environment.

Poor ground connections are often the first problem that develops from an interior water lake. Many weird electrical problems can start to develop from poor or intermittent ground connections. If you’re interested in what other repairs this car needed you can visit the Z section of this blog. This next link takes you there from this page about 300zx water leaks.