2016-2021 McLaren 570S Fender Insulator: Fitment, Failures, and Replacement Guide

Symptoms of a Failing Fender Insulator

Failure of a fender insulator is typically not subtle. Due to their location near the hot exhaust and spinning tires, symptoms are usually audible or visible.

1. Rattling or Scraping Noises

The most common symptom is noise. A loose, damaged, or sagging insulator can make contact with the tire or vibrate at speed, creating rattling, buzzing, or scraping sounds from the rear of the vehicle. This noise may be more pronounced when driving over bumps or at higher speeds.

2. Visible Damage or Sagging

A visual inspection can often confirm the problem. Look inside the rear wheel wells for any part of the liner that is hanging down, cracked, melted, or appears brittle. The material, often a heat-molded fibrous composite, can degrade from constant heat cycles and exposure to the elements.

3. Increased Cabin Noise

Because the insulators provide acoustic dampening, a damaged or missing section can lead to a noticeable increase in road, tire, and engine noise inside the cockpit.

Known Issues, TSBs, and Recalls

As of late 2023, there are no specific recalls or Technical Service Bulletins (TSBs) from McLaren or the NHTSA directly related to the fender insulators on the 570S. Most documented issues for this vehicle relate to other areas such as airbag inflators, brake banjo bolts, and minor electronic glitches. 🎬 Watch: Common McLaren 570S issues and recalls explained However, forums and owner communities report that corrosion on aluminum body panels, including around wheel arches, can be a concern on some examples, making the proper fitment of liners and insulators important for preventing moisture collection.

Buying a Used Fender Insulator: An In-Depth Guide

Given the high cost of new OEM parts for McLaren vehicles, a used OEM insulator is often the most practical solution. Here’s what to look for to ensure you get a quality part.

1. Crucial Compatibility Check: Coupe ONLY

This is the most important check. The fender insulators with part numbers 13AA285SP and 13AA287SP are for the 2016-2021 McLaren 570S Coupe only. They will NOT fit the 570S Spider (convertible) or the 570GT models. The rear body structure, roofline, and engine cover differ significantly on the Spider and GT, requiring a different shape and mounting points for the insulators. Always verify the part is from a Coupe model before purchasing.

2. Physical Inspection Checklist

• Check for Heat Damage: Inspect the entire surface for signs of melting, warping, or charring. The area closest to the engine and exhaust is most susceptible. The material should be firm, not brittle or crumbly.
• Verify All Mounting Points: Carefully check that all bolt holes and clip-on points are intact. Cracked or broken mounting tabs are a major red flag, as the insulator will not sit securely, leading to rattles or detachment.
• Look for Tears and Cracks: Examine the full surface for any tears, cracks, or holes. Even small damage can allow water and debris into sensitive areas and compromise the part's insulating properties.
• Assess Material Integrity: The fibrous material should not be saturated with oil or other fluids. It should be dry and relatively clean. A fluid-soaked insulator can be a fire hazard and indicates other potential leaks in the donor vehicle.

3. Why Used OEM is the Smart Choice

For a specialized part like this on a supercar, aftermarket options are virtually nonexistent and would likely not meet the specific thermal and acoustic requirements. A used OEM part ensures you get:

• Perfect Fitment: Engineered by McLaren for the 570S, guaranteeing it aligns with all mounting points and body contours.
• Correct Materials: The original part uses materials specifically chosen for their heat resistance and sound-dampening properties, which are critical in this application.
• Cost Savings: A used OEM insulator provides the same form and function as a new one for a fraction of the price.

Cost Comparison

Note: Prices are estimates and can vary based on supplier, condition, and location. New OEM pricing is particularly difficult to pinpoint and can be very high from dealerships.

Replacement Information

Replacing the fender insulator is a straightforward task for a DIY mechanic with the right tools.

• Difficulty: 2 out of 5
• Estimated Time: 0.5 - 1 hour per side
• Tools Required: Jack, jack stands, lug wrench or impact gun, socket set, trim removal tools.

Basic Replacement Steps:

1. Safely Lift the Vehicle: Use a jack on the appropriate lift point and secure the vehicle with a jack stand. Never work on a car supported only by a jack.
2. Remove the Rear Wheel: This provides the necessary access to the wheel well.
3. Remove Fasteners: Locate and remove the screws and plastic clips holding the old insulator in place. They are typically located along the perimeter of the wheel arch.
4. Remove the Old Insulator: Carefully maneuver the old insulator out of the wheel well.
5. Install the New Insulator: Position the replacement insulator, ensuring all mounting holes line up correctly.
6. Reinstall Fasteners: Secure the new insulator with all original screws and clips. Do not overtighten.
7. Reinstall the Wheel: Mount the wheel and torque the lug nuts to the manufacturer's specification.
8. Lower the Vehicle: Remove the jack stand and lower the car.

Frequently Asked Questions (FAQ)