Degreasing The Engine Compartment

Introduction

Degreasing the engine compartment is a critical step when restoring or rebuilding a Ford Bronco II. Years of oil spills, power steering leaks, and road grime can coat the frame rails, suspension, and engine bay—especially on the driver’s side. Before installing a clean or rebuilt engine, the engine compartment must be thoroughly cleaned to prevent contamination, identify hidden damage, and prepare surfaces for repainting.

This page documents how I degreased the engine bay on my Project Bronco II using oven cleaner and a pressure washer after removing the original engine. The process reveals common problem areas on early Ford trucks and SUVs, including grease buildup, factory primer exposure, and overlooked mechanical issues.

WARNING: Make sure when you do this you use a face mask to protect yourself from the oven cleaner fumes. You should also avoid getting the cleaner on electrical connections.

WARNING: Oven cleaner can strip off old paint. I would not use oven cleaner on anything that has paint that you don’t want to damage or on anything that you don’t plan to repaint.

Tools and Materials Used

• Heavy-duty oven cleaner
• Pressure washer
• Face mask or respirator
• Safety glasses and gloves
• Access to a self-service car wash

Old vehicles like the Project Bronco II can be a greasy mess. It seems that the biggest portion of it is always on the driver’s side of the engine compartment. You can thank greasy engines and engine compartments to people spilling engine oil while adding it, and leaky power steering pumps.

I planned on putting a clean and detailed engine in the Bronco II, but I wasn’t about to put it in a greasy and dirty engine compartment. That meant a good degreasing was in order.

After the old motor was out, I loaded the Bronco II up on the trailer and took it to a local do-it-yourself car wash.

Those cans of degreaser you get from the parts stores never work well for me, so I went to the local dollar store and got some cheap heavy duty oven cleaner. Degreasing the Bronco II would consist of spraying it down really good with oven cleaner and hitting it with the pressure washer.

You can see from the (2) photos below how messy the driver’s side frame rail was.

Here it is the morning after I cleaned it at the car wash with oven cleaner:

See all that gray area? That’s the factory primer. The oven cleaner and pressure washer actually washed away the factory paint. Not a big deal for me because I will be repainting this.

During cleaning, I discovered a severely kinked lower radiator hose. Restricted coolant flow can cause overheating, oil breakdown, and internal engine damage. This likely contributed to the engine knock reported by the previous owner and reinforces why cleaning and inspection are critical before diagnosing engine failure.