My 2005 Neon has had a leaking problem for quite some time. I live in Portland, Oregon and it rains…a lot! After a decent rainfall, when I start the car and the first couple times I accelerate, there is an audible hissing sound, and then the water drips in from underneath the dash on the passenger side. The leak is getting progressively worse, and I’m concerned the interior carpets will get moldy. I recently brought the car in for it’s 60K checkup, and all is good. The only thing they could find leaking are the seals on the passenger door. Unfortunately, these seals aren’t made anymore, and the cost to purchase them is quite expensive, and may or may not fix the leaking issue. I’m wondering if anyone else has had similar leaking issues with this make and model, and if so, what the solution might be. Thank you!
I suspect you have a clogged drain in the ventilation system. Rainwater comes down the windshield and enters the fresh air intake (the opening is in the cowl between the wipers). The intake has a drain at the bottom. If it is clogged, the water is trapped until it builds up to where it can spill out into the car’s interior.
You can try to unclog the drain yourself by locating its outlet in the engine compartment; it is a short (1") section of hose coming through the engine firewall. Poke it with a stiff wire. If you can’t handle this job, ask to shop to do it for you.