In this video, Bradley cleans and conditions the engine bay of a 2014 Nissan Frontier with 150,000 miles. He walks through preparation, degreasing, careful rinsing, and finishing the painted, plastic, and rubber surfaces with Armour Detail Supply products.
Watch the full engine bay cleaning walkthrough.
Inspect the Vehicle Before Choosing a Wet Cleaning Method
The 2014 Nissan Frontier in Bradley's demonstration has 150,000 miles of accumulated grime. The process improves its appearance dramatically, but the right cleaning method still depends on the condition and design of the vehicle in front of you. Do not assume an older engine bay, an aftermarket intake, and a modern sealed assembly can all be rinsed in the same way.
Begin with the engine switched off and fully cool, and secure the hood. Consult the vehicle's cleaning instructions and inspect for exposed wiring, damaged connectors, missing covers, open intake components, and deteriorated seals. If a component cannot tolerate the proposed cleaning method, protect it or choose a controlled wipe-clean approach instead.
For example, Ford's engine-cleaning guidance identifies electrical and intake precautions. Use your own vehicle's instructions to determine which areas may be rinsed. This conventional engine-bay demonstration should not be transferred to high-voltage components on a hybrid or EV.
Remove Loose Debris and Work from the Top Down
Vacuum or lift out leaves and loose material around the cowl and accessible corners before adding water. This makes the chemical stage more efficient and keeps debris from moving into drains and recesses.
Clean the underside of the hood before the main engine bay so loosened dirt does not drip onto an area you have just finished. Treat hood insulation gently: avoid soaking it, blasting it with pressure, or scrubbing its fibers aggressively. Damaged or sagging insulation needs assessment rather than more water.
Some staining may remain on the underside paint even after cleaning. Bradley points out the limits of restoring an older, long-neglected surface. Do not keep increasing chemical strength or abrasion simply to make aged material look factory-new.
Set Up the Cleaner and Tools
Bradley uses CLEAN APC at 4:1, meaning four parts water to one part concentrate, for the compatible surfaces in this job. Follow the current directions, test a small area, and avoid letting the solution dry.
Gather brushes of suitable size and stiffness, a microfiber mitt or towels for broader areas, and separate finishing towels. A small detailing brush reaches around accessible shapes, while a soft mitt cleans larger plastic covers without requiring a stiff brush over every surface.
Keep your tools clear of belts, fans, pulleys, and other moving assemblies. Leave the engine off throughout the hands-on cleaning. Wear the protection specified on the cleaner label and avoid spraying chemicals toward your face while reaching into the bay.
Clean in Controlled Sections
- Apply cleaner only where appropriate. Use controlled coverage, avoiding openings and components excluded by the vehicle's instructions.
- Agitate accessible grime. Work the brush around compatible plastic, painted, and rubber surfaces. Change tools for tight areas instead of forcing a large brush against wiring.
- Monitor the cleaner. Work smaller areas if heat or airflow is shortening the dwell time. Never leave it to dry.
- Rinse gently where permitted. Remove chemical and loosened dirt without directing pressurized water at electrical connections, ignition parts, or intake openings.
- Inspect before escalating. Repeat a targeted cleaning step only where needed rather than applying stronger cleaner across the entire bay.
Bradley spot-cleans stubborn grease with diluted Tire Cleaner. Check material compatibility and the format in your hand: the current 16-ounce Tire Cleaner is already diluted, while the gallon is concentrate. Do not copy a concentrate dilution onto a ready-to-use bottle without accounting for that difference.
Separate Remaining Dirt from Permanent Aging
Once the cleaner is rinsed away, look for grease in corners, drip trails from the hood, and residue on accessible covers. Those may benefit from another controlled pass. Oxidation, staining, and deteriorated material are different problems and may remain after the dirt is gone.
A cleaner engine bay should not require removing every trace of age. Avoid pursuing a cosmetic result at the expense of a label, fragile insulation, connector, or worn surface. If you find damage or a leak during inspection, address that separately from detailing.
Protect Suitable Surfaces Without Leaving Pooling
In the demonstration, Bradley applies BEADS to suitable painted areas with a spray-and-rinse process. Use it only where the vehicle and product directions permit and where you can rinse completely. Our BEADS guide explains the application sequence.
He also shows diluted Tire+ for dressing compatible plastics and rubber, discussing dilutions between 4:1 and 10:1 for the finish he wants. Keep dressing off belts, pulleys, braking parts, electrical components, and hot exhaust areas. For precise placement, apply with a towel or applicator rather than indiscriminate spraying.
Allow the treatment to settle, then level accessible surfaces with a microfiber and remove pooling. A blower can help clear retained water from suitable areas, but it does not make water-sensitive assemblies safe to saturate in the first place.
Final Check Before Closing the Hood
Make sure all protective coverings are removed, caps and covers are correctly fitted, and the engine bay has dried appropriately before restarting according to the vehicle's instructions. Collect towels and tools, check for remaining chemical residue, and inspect the surrounding fenders.
Bradley does engine-bay work before the exterior wash so the later wash removes overspray and drips. Our maintenance wash guide covers that exterior sequence.
Do I need a pressure washer?
No. The priority is controlled cleaning suited to the vehicle. A high-pressure jet aimed at the wrong component can create a problem that gentle, targeted cleaning avoids.
Can dressing hide an incompletely cleaned engine bay?
It may darken the surface temporarily, but grease and dirt underneath still need cleaning. Clean first, dry as required, and apply only enough suitable dressing for an even finish.