How to Replace the Fuel Cap on a 2018 Chevrolet Malibu (Fix EVAP Leak & Check Engine Light)
Step-by-step fuel cap replacement with safety tips, required tools/parts, and post-repair checks
How to Replace the Fuel Cap on a 2018 Chevrolet Malibu (Fix EVAP Leak & Check Engine Light)
Step-by-step fuel cap replacement with safety tips, required tools/parts, and post-repair checks
đź”§ Malibu - Fuel Cap Replacement
Replacing the fuel cap on your Malibu is a quick job: you remove the old cap and install the new one until it clicks. A good cap seals the fuel system, helps prevent fuel vapors from escaping, and can stop an EVAP-related check engine light caused by a leaking cap.
Difficulty Level: Beginner | Estimated Time: 0.1-0.2 hours
⚠️ Safety & Precautions
- â›˝ Turn the engine OFF and keep away from flames/sparks while the fuel door is open.
- 🧤 Avoid breathing fuel vapors; work in a well-ventilated area.
- đź§Ż Do not smoke; gasoline vapors ignite easily.
- 🔋 Battery disconnect is not required for this repair.
đź”§ Required Tools
You'll need the following tools for this repair:
- Nitrile gloves
- Safety glasses
- Clean shop towel
- Flashlight
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Fuel cap - Qty: 1
đź“‹ Before You Begin
- 🅿️ Park on level ground, shift to Park, and shut the engine off.
- đź•’ If you just drove, wait a minute so vapors can settle.
- đź§˝ Wipe dirt off around the fuel filler opening using a clean shop towel.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Open the fuel door
- Use your hand to open the fuel door on the left rear side of your Malibu.
- Use a flashlight if it’s dark so you can see the cap and sealing area.
Step 2: Remove the old fuel cap
- Put on nitrile gloves and safety glasses.
- Turn the fuel cap counterclockwise (left) until it releases, then pull it off.
- If your cap has a tether (the small strap that keeps it from getting lost), let it hang—don’t yank it. Tether = the little retaining strap.
Step 3: Inspect and clean the sealing surfaces
- Use a clean shop towel to wipe the metal/plastic lip where the cap seals.
- Make sure there’s no dirt, sand, or cracked rubber left behind from the old cap’s seal.
Step 4: Install the new fuel cap
- Place the new cap onto the filler neck and turn it clockwise (right).
- Tighten by hand until you hear/feel it click (usually several clicks).
- Clicks matter—this is the proper seal.
Step 5: Close the fuel door
- Close the fuel door firmly with your hand.
- Use the clean shop towel to wipe any fingerprints or fuel residue if needed.
âś… After Repair
- 🟢 Start the engine and confirm there is no fuel smell around the fuel door area.
- 🔎 If you were replacing the cap due to a check engine light, it may take a few drive cycles to clear on its own (or a scan tool can clear it immediately).
- âś… Recheck that the cap still clicks and feels snug after your next fill-up.
đź’° DIY vs Shop Cost
Shop Cost: $30-$90 (parts + labor)
DIY Cost: $15-$45 (parts only)
You Save: $15-$45 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.1-0.2 hours.
🎯 Ready to get started?
HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.

















