Which to Install First: Underbody Coating or Engine Guard Plate?
2 Answers
Underbody coating and engine guard plate, install the underbody coating first. Function of engine guard plate: The engine guard plate is used to protect the engine and is generally installed under the front chassis of the vehicle to prevent the engine from being damaged by impacts. Depending on the vehicle brand and model, whether a new car comes with an engine guard plate pre-installed from the factory varies. Whether to install an engine guard plate mainly depends on the driving road conditions. If the driving environment is good, there is no need to install a guard plate. Occasionally encountering rough roads, slowing down in advance and passing slowly can help. Improper installation of the guard plate may cause abnormal noises and wind noise. If the driving road conditions are relatively poor, installing a guard plate can be considered. Function of underbody coating: The underbody coating mainly prevents corrosion and, to a lesser extent, protects against stone impacts and vibrations. It can prevent moisture, acid rain, and salt from eroding the vehicle's underbody, thereby extending the vehicle's lifespan. Manufacturers apply an anti-corrosion coating to the underbody when the vehicle leaves the factory. If the driving area is prone to rain, snow, or is near the coast, it is recommended to apply an additional layer.
I believe it's more reasonable to install the chassis armor first. The chassis armor is a protective coating sprayed onto the undercarriage, primarily for rust and corrosion prevention, and it requires the entire chassis surface to be clean and smooth for proper adhesion. If the engine guard is installed first, it will block certain areas of the chassis, resulting in uneven application of the armor and reduced effectiveness. Personally, when working on cars, I prefer to lift the vehicle, clean it thoroughly, apply the armor, let it dry, and then install the guard. This avoids coverage issues and makes it easier to align the guard's screws. Reversing the order may lead to missed spots in the armor application or uneven installation of the guard, compromising long-term protection—especially in humid conditions where the chassis is more vulnerable. Therefore, from an installation process perspective, prioritizing the armor is more efficient and thorough.
