An engine bay looks complicated because several systems live in the same small neighborhood. You do not need to memorize every hose to get started. I would learn the everyday service points first, then let each job introduce the next layer. Curiosity is useful; pouring something into an unidentified opening is less useful.
My recommendation: learn these landmarks with a cool, switched-off engine before buying fluids or reaching for a tool.
Before I reach for a tool
I read the whole job first. Then I get the car, the parts and myself ready.
- Park safely and secure the vehicle
- Switch the engine off and let hot parts cool
- Identify the engine: 2.3L, 3.7L or 5.0L
- Open the hood and make sure its lift supports hold it securely
Look first; leave unfamiliar caps alone
Coolant and washer fluid are not interchangeable. Coolant in the washer system can impair visibility. Never open a hot or running engine’s coolant reservoir.
Match the engine before matching the picture
Your engine-bay field map
2.3L EcoBoost
3.7L V6
5.0L V8
- 1Battery
- 2Oil dipstick
- 3Oil filler cap
- 4Brake-fluid reservoir
- 5Engine air cleaner
- 6Coolant reservoir
- 7Washer-fluid filler
- 8Power distribution box
The drawings below are independently drawn location maps, viewed from the front bumper looking toward the windshield. Your right side of the drawing is the vehicle’s left side. Parts are simplified for recognition; hose routing, dimensions, and fastener positions are not represented.
Factory layout matters. An aftermarket intake, relocated battery, or engine conversion can change what you see. The labels on the actual car and its build information take priority over a familiar silhouette.
Eight places worth knowing
The oil cap and dipstick move between engines. In the 2.3L layout the oil cap is near the rear of the engine and the dipstick is farther forward. The V6 places both toward the vehicle’s left side. The V8 puts the oil cap on the vehicle’s right side and the dipstick on the left. Use the engine-specific map rather than transferring a location from a different Mustang.
| Landmark | What it belongs to |
|---|---|
| Battery | Electrical energy storage; behind its cover in the 2.3L and 5.0L reference views |
| Oil dipstick | The removable gauge used to measure engine oil level |
| Oil filler cap | The opening for adding the correct engine oil |
| Brake-fluid reservoir | The reservoir for the documented brake/clutch fluid check |
| Engine air cleaner | The housing containing the engine’s replaceable air filter |
| Coolant reservoir | The marked reservoir in the engine cooling system |
| Washer-fluid reservoir | The filling point for windshield-washer fluid |
| Power distribution box | The under-hood electrical fuse and distribution enclosure |
The reservoir that is not missing
This Mustang uses electric power steering. There is no power-steering-fluid reservoir to find, check, or fill. A steering fault is a diagnosis question, not an invitation to add fluid somewhere nearby.
The 2015 owner publication also describes a fuel filter integrated with the tank and gives it no routine replacement requirement. That does not rule out a fuel-system fault or authorize opening the tank; it distinguishes the service schedule from a repair.
What I check before wrapping up
- The selected map matches the engine
- I can tell the washer reservoir from the coolant reservoir
- I can identify both the oil cap and dipstick
- The hood closes and latches securely afterward
Sources & editorial notes
Original Atlas writing and independently drawn illustrations, based on the technical facts below. First-person comments express editorial judgment, not a claim of hands-on testing. Applicability follows the cited edition.
- Engine-compartment layouts, electric steering and fuel-filter service scope2015-Mustang-Owners-Manual-version-1_om_EN-US_07_2014.pdfPDF file pages 214, 215, 216, 222, 223 · counted from the first PDF page, which may differ from printed page numbers
This guide covers the topic and vehicle configuration stated above. The source register tracks the developing library; the full four-PDF collection has not yet been re-authored.