No, you should never intentionally pour or spread oil over your engine compartment. Doing so is extremely dangerous and can cause severe damage. Engine oil is a petroleum-based product that is highly flammable. Coating electrical components, wiring harnesses, or hot surfaces like the exhaust manifold with oil creates a significant fire hazard. It can also degrade rubber hoses and plastic parts over time, leading to premature failures. If you have an oil spill, the correct approach is to clean it thoroughly, not spread it around.
The primary risk is a engine bay fire. Modern engine compartments are packed with electrical connections, sensors, and hot surfaces. Oil on these components can ignite from heat alone. Furthermore, oil is an electrical insulator when fresh but can become conductive as it collects dirt and metal particles, potentially leading to short circuits in the fuse box or wiring.
If you have an oil leak that has coated parts of the engine, it needs to be properly cleaned. For small spills, use a dedicated engine degreaser. Spray it on the affected areas, let it sit to break down the oil, then carefully rinse with low-pressure water, avoiding direct sprays on the alternator, air intake, and electrical connectors. For large spills or a major leak, it's safest to have a professional mechanic handle the cleaning after repairing the source of the leak.
The idea of "oiling" the engine bay might stem from a misunderstanding of using dielectric grease on electrical connections to prevent corrosion, or from seeing undercoating sprays for rust protection on a vehicle's frame. These are specific products for specific purposes; general motor oil is not a substitute.
| Component at Risk | Potential Consequence of Oil Coating |
|---|
| Alternator / Starter Motor | Short circuits, internal failure, loss of battery charging. |
| Spark Plug Wires / Ignition Coils | Electrical arcing, engine misfires, rough running. |
| Serpentine Belt | Belt slippage, squealing, loss of power steering/AC. |
| Rubber Hoses (Coolant, Vacuum) | Swelling, softening, and eventual rupture. |
| Exhaust Manifold / Catalytic Converter | Smoke, foul odor, and high risk of fire. |
| Engine Sensors (O2, MAF) | Contamination and inaccurate readings, triggering check engine light. |
