BYD Shark Water Leak & Rust: Find The Cause, Fix The Damage

BYD Shark water leak – Rust found under the dash during install. Learn causes, fixes & how to prevent costly leaks early.

During a routine dash camera and tow controller installation, a technician discovered a serious concern in a BYD Shark – water pooling under the driver’s side carpet and rust forming on hidden metal parts beneath the dash. What seemed like a one-off quickly turned into a broader issue, as other owners shared similar experiences online.

In this post, I’ll walk you through what to look for, how to deal with early rust, and the preventative steps every BYD Shark owner should take before a small leak turns into a big repair bill.

No Official BYD Service Bulletin Yet

So far, a search of publicly available documents hasn’t turned up any official BYD service bulletin addressing water leaks or rust under the dash in the Shark 6. That means owners don’t currently have a published, step-by-step recall or service campaign to reference.

What Owners Are Hearing from BYD Service Centres

Even though there’s no public bulletin, several owners have reported on Reddit and other forums that BYD service centres are acknowledging the issue when raised. In some cases, the repairs have been covered under warranty, and at least one owner mentioned being provided with a loaner vehicle while their Shark was in for work. That suggests BYD may be handling the issue case by case rather than through an official recall.

Examples from New Zealand: BYD Covering Rust Repairs

Coverage also extends beyond Australia. A CleanTechnica article highlighted cases in New Zealand where BYD took rust complaints seriously, even involving a country manager to oversee repairs. In those instances, BYD reportedly paid for extensive rust repairs under warranty, setting a precedent that the company is willing to step in when corrosion is detected early. Here is the link to the CleanTechnica article:

BYD Atto 3 Rust Issues Down Under — BYD Responds Promptly

1. Diagnosing the Water Entry Point: Where is the Water Coming From?

Finding the rust is only half the battle; stopping the water leak is the key to preventing it from coming back. Based on common issues in modern cars and owner reports, the water ingress is highly likely caused by a blocked or faulty drain path around the firewall, not the main door seals.

The Most Likely Suspect: Misaligned/Clogged Drain Holes

The current consensus among owners and technicians dealing with this issue points to a potential manufacturing fault or blockage involving the drains in the cowl area (the panel below the windscreen wipers) or behind the front fender.

• The Suspected Fault: Owners have reported service centres acknowledging an issue where two sets of drain holes in the cabin or cowl area don’t line up correctly, causing water to pool and overflow into the cabin space under the dash.
• The Reported Fix: In some cases, dealers have been redrilling the lower set of drain holes to create a clear path for water to exit the vehicle before it backs up into the cabin.

If you are a BYD Shark owner, this is the specific detail you should mention to your dealer when raising the warranty claim.

Quick Water Leak Diagnosis Checklist

If you are diagnosing the leak yourself, check these common entry points first:

1. Cowl Panel Drains: Open the bonnet and inspect the plastic panel at the base of your windshield (the cowl or scuttle panel). Debris, leaves, and mud can easily clog these drains, forcing rainwater to back up and enter the cabin through the fresh air intake or firewall grommets.
2. AC Condensate Drain: The air conditioning system creates condensation (water) that should exit the vehicle through a small rubber hose that passes through the firewall, usually on the passenger side. If this hose is clogged, water backs up inside the dash and spills onto the floor.
3. Firewall Grommets: Since the leak was discovered during a dashcam installation, check any aftermarket wiring that passes through the firewall (for the dashcam, tow controller, etc.). If the grommet wasn’t seated correctly, or if the cable doesn’t fill the hole, it creates a direct path for water to leak down onto the driver’s footwell.

If you’re worried about corrosion on a used vehicle, check out our Visual Guide to Car Rust Inspection to see common failure points on 4WDs and passenger cars.

2. Step-by-Step Access and Drying Guide

Dealing with wet carpet is critical, as the thick foam insulation underneath can hold water for weeks, continuing to promote rust and mould. You must dry the area completely before attempting any rust repair.

A. Exposing the Wet Floor Pan

1. Disconnect Battery: Always disconnect the 12V battery before pulling up interior trim to avoid airbag faults or electrical shorts.
2. Remove Trim: Carefully remove the plastic sill trim (kick plate) along the door opening. These typically use clips – a plastic trim removal tool is highly recommended.
3. Lift the Carpet: Starting from the door opening, gently pull the carpet up. It is attached to thick foam sound-deadening material. You do not need to remove the entire seat, but you will need to lift the carpet enough to expose the bare metal floor underneath the wet area.
4. Prop It Up: Use a piece of wood or a small bottle to prop the carpet and foam up, keeping the metal floor completely exposed.

B. Drying the Substrate

Water trapped in the thick sound-deadening foam is the main culprit for ongoing rust.

• Use a Wet Vacuum: If there is standing water, use a wet/dry vacuum to extract as much liquid as possible from the carpet and the foam padding.
• Apply Targeted Heat & Air: Place an oscillating fan directly into the exposed footwell. For a faster, professional approach, consider renting a dehumidifier for a few days – this is far more effective than just heat for drying the foam.
• Check Electricals: Once dry, check for any visible corrosion or damage to wiring harnesses that may have been submerged, particularly near the kick panel fuse box (if applicable).

3. The Warranty and Liability Checklist

Before you start any DIY repair, consider your warranty position.

Related Video: Comprehensive Water Leak Diagnosis

Since a specific BYD Shark repair video for this exact issue is not yet available, this comprehensive tutorial will guide you through the process of locating a difficult water leak, which is the necessary first step. It covers the common culprits in the dash/firewall area that you need to investigate.

Video Title: How to Find Water Leaks in a Car

BYD Shark 6 Rust Repair:

1. Dry it out – get that area bone-dry, check door seals and clear any clogged drains.
2. Neutralise the rust with a trusted converter like CRC Rust Converter Aerosol (425 g) – it bonds to rust, turning it into a stable primer and blocks moisture on treated surfaces.
3. Reform stubborn spots using Rust‑Oleum Stops Rust Reformer (290 g aerosol) – spray right onto lightly sanded areas; it chemically transforms rust into a flat-black, non-rusting coating.
4. Protect and seal – once cured, coat the surrounding metal with a rust-inhibiting wax or sealant.
5. Stay vigilant – check these hidden zones regularly and act fast if you spot moisture or bubbling paint again.

BYD Shark Water Leak Cargo Area Fix

A common source of water leaks in the BYD Shark can be the cargo area, where poor sealing allows moisture, dust, or even mud to creep in. One of the most effective solutions is to install a BYD Shark Seal Kit that’s designed specifically for this model.

These kits are made from high-elastic rubber and stainless steel, creating a durable, waterproof barrier. They not only stop water seepage but also reduce noise and impact in the cargo box. Best of all, installation is simple, no drilling required. The seals mount using existing points and are secured with screws, making it a quick DIY fix.

👉 Protect your cargo area with the BYD Shark Seal Kit – Waterproof & Noise Reduction.

Trust me, catching rust early is miles cheaper than replacing parts later. Prevention wins every time.

General Rust Information from AutoGuru

While not BYD-specific, AutoGuru provides general advice on how and why rust forms in vehicles and what repair methods are usually recommended. This includes cleaning, sanding, rust conversion, priming, and sealing to prevent further spread. It’s a useful context, but again, it doesn’t confirm any official BYD position.

BYD Shark 6 “Rescue Sheet” Isn’t About Leaks

Interestingly, the search results did uncover a BYD Shark 6 Rescue Sheet – a guide for first responders if the vehicle is submerged in water. It advises shutting off the high-voltage system and draining water after a flood event. However, this document is written for emergencies, not slow leaks or trapped moisture under the dash, so it doesn’t provide any answers for the current rust concerns.

Many BYD Shark 6 owners have reported similar issues online. In one discussion on Reddit’s BYD Shark owners group, drivers shared cases of water pooling under carpets and early signs of rust beneath the dash.

To fully protect yourself when purchasing a vehicle, access the used car buyer’s defensive shield by conducting a comprehensive vehicle inspection.

While the BYD Shark is the new kid on the block, facing teething issues like water leaks, it isn’t the only value-driven heavy hitter with specific quirks. If you are cross-shopping or already own a large budget SUV, be aware of the common mechanical issues found in other popular models.

Don’t let budget-friendly brands catch you off guard. Check out my comprehensive guide on LDV D90 problems and DIY survival fixes to see how they compare.