Gas Smell When Starting Car in Cold: Quick Fixes and Prevention Tips

Here’s what to do if you find gas smell when starting car in cold

When starting a car in cold weather, it’s not uncommon to notice a strong gasoline smell. This can be concerning for drivers, but understanding the cause of this odor can help ease any worries.

In this article, we will discuss various factors that may contribute to this issue, as well as steps to diagnose and remedy it.

Gasoline smells can be attributed to several factors, some of which may be related to the temperature drop. Understanding the most common causes is essential for accurately diagnosing the problem and applying appropriate solutions.

Gas Smell When Starting Car in Cold

It’s important to address any gasoline odors promptly, as they may indicate potential leaks or mechanical issues that could pose a hazard to the vehicle and its occupants.

By following a systematic approach and considering preventive measures, most issues that cause gasoline smells when starting a car in cold weather can be resolved effectively and efficiently.

Keep reading to learn more about diagnosing, fixing, and preventing gas smells in your vehicle during cold startups.

Also read: Car Shakes on Cold Start – What Can You Do?

Key Takeaways

  • Gasoline smells during cold startups may indicate underlying issues
  • Accurately diagnosing the cause is essential for proper fixes
  • Regular maintenance and preventive measures can help avoid gas odors

Understanding Gas Smells in Cars

Causes in Cold Weather

  • Refueling: The gas smell may be noticed after refueling, as fumes can enter the car’s cabin. The odor should dissipate after a few minutes.
  • Loose gas cap: A loose gas cap can cause gas fumes to waft into the car’s interior. Tightening the cap should fix the problem.
  • Fuel leak: Gas leaks in cold weather can be due to damaged fuel lines or punctured fuel tanks. Check for puddles under your car to identify a leak.

Example: If you recently filled up your tank and notice a gas smell, consider checking your gas cap first, then look for any puddles under your car to rule out a leak.

Dangers of Ignoring the Smell

  • Health risks: Prolonged exposure to gas fumes can lead to headaches, dizziness, and nausea.
  • Fire hazards: Ignoring a gas leak can result in a fire, as gasoline is highly flammable.

Comparison Table:

CauseSolutionConsequence of Ignoring
RefuelingAllow fumes to dissipateMild health issues
Loose gas capTighten gas capGas fumes in cabin
Fuel leakRepair damaged fuel lines or fuel tankSerious fire hazard, damage

Common Causes of Gas Smells

Gas Cap Issues

  • Loose or damaged gas cap
  • Problems with the rubber gasket

A common cause of gas smell when starting your car in cold conditions is a gas cap issue. A loose or damaged gas cap can release gasoline fumes, which contributes to the smell.

The rubber gasket on the gas cap may also be responsible for the smell, if it’s worn or damaged.

Fuel System Leaks

  • Punctured fuel tank
  • Faulty fuel lines

Fuel system leaks are another possible source of gas smell. A faulty fuel line or a punctured fuel tank can allow gasoline to leak out and produce a gas smell.

Leaking fuel injectors, hoses, or fuel rail can also contribute to the smell. A damaged fuel filter or pressure regulator might be responsible for the leak as well.

ComponentIssueGas Smell Contribution
Fuel tankPunctureYes
Fuel lineFaulty or damaged connectionsYes
Fuel injectorsLeakageYes
Fuel hosesPuncture or wearYes
Fuel railLeakageYes
Fuel filterDamage, wearYes
Pressure regulatorFaultyYes

EVAP System Problems

  • Broken charcoal canister
  • Issues with the EVAP system components

The EVAP (Evaporative Emissions Control) system is designed to reduce gasoline smell and emissions by trapping gas vapors in a charcoal canister.

Despite its effectiveness, problems with the EVAP system can cause gas fumes to escape, leading to the smell when starting your car.

A broken charcoal canister or issues with other components of the EVAP system can result in the smell.

Oil Leaks

  • Damage or wear in the engine’s gaskets or seals
  • Leaking oil coming into contact with hot engine components

Gas smell can also be the result of oil leaks. Damaged or worn engine gaskets and seals can allow oil to leak out.

Leaking oil can come into contact with hot engine components like spark plugs, producing a noticeable gas odor.

Diagnosing Gas Smells

Visual Inspection

A gas smell when starting your car in cold could indicate a potential issue with the fuel system. Begin with a visual inspection:

  • Check for puddles of gas under your vehicle
  • Inspect the fuel line for leaks or damage
  • Look for cracks or punctures in your fuel tank

For example, a punctured fuel line or damaged fuel tank can cause a strong gas smell. It’s recommended to have a mechanic check these components thoroughly, as it could be dangerous if ignored.

Using a Scan Tool

Sometimes, a gas smell can be related to issues with your car’s engine-management system. You can use a scan tool to help diagnose these problems:

  1. Connect the scan tool to your vehicle’s OBD-II (on-board diagnostic) port
  2. Turn on your car to initiate the connection between the tool and the vehicle’s computer
  3. Read the displayed trouble codes to pinpoint the issue

For example, a faulty fuel injector or a failing EVAP system might trigger the check engine light and generate a specific code. A professional mechanic can help clarify the meaning of these codes and recommend necessary repairs.

Fixing Gas Smell When Starting Car in Cold

Gas Cap Replacement

One reason for a gas smell when starting your car can be a loose or damaged gas cap. Replacing a car gas cap is a simple task that requires minimal tools and time. Here’s a step-by-step guide on how to replace a car gas cap:

Tools and Materials Needed:

  • New gas cap (make sure it’s compatible with your vehicle)
  • Gloves (optional)
  • Rag or paper towel (for cleaning)
  • Safety glasses (optional)


  1. Park Safely: Ensure your vehicle is parked in a safe and well-ventilated area, preferably on level ground. Turn off the engine and allow it to cool down if you’ve been driving.
  2. Open the Fuel Door: Locate the fuel door release lever inside your car, usually located near the driver’s seat or dashboard. Pull the lever to open the fuel door.
  3. Remove the Old Gas Cap: Unscrew the old gas cap from the fuel filler neck by turning it counterclockwise. If the cap is tight, you can wear gloves or use a rag for better grip. Set the old gas cap aside.
  4. Inspect the Filler Neck: While the gas cap is off, take a moment to inspect the filler neck for any visible signs of damage, debris, or corrosion. Clean the area around the neck with a rag or paper towel if needed.
  5. Prepare the New Gas Cap: Remove the new gas cap from its packaging. Check to ensure that it’s the correct size and compatible with your vehicle’s make and model.
  6. Install the New Gas Cap: Align the new gas cap with the fuel filler neck threads. Insert the cap onto the neck and begin turning it clockwise (right) by hand. Twist the cap until you feel resistance.
  7. Tighten the Gas Cap: Use your hand to tighten the gas cap firmly. It doesn’t need to be overly tight; just ensure it’s snug enough to create a proper seal.
  8. Close the Fuel Door: Gently close the fuel door to secure the new gas cap in place.
  9. Check for Proper Sealing: After installing the new gas cap, start the engine and let it run for a few minutes. Check around the filler neck and the gas cap for any signs of leaks or hissing sounds. If you notice any issues, turn off the engine and inspect the cap for proper installation.
  10. Reset the Check Engine Light (if applicable): In some vehicles, a loose or missing gas cap can trigger the check engine light. If the light comes on, it should go off within a few driving cycles once the new gas cap is properly installed. However, if it doesn’t go off, you may need to use an OBD-II scanner to reset the check engine light.

If there’s a worn-out o-ring, replacing it can help seal the cap properly and prevent fumes from escaping.

Fuel Line Repair

A cracked or punctured fuel line can also cause a gas smell. To address this, you should:

Repairing a fuel line can be a critical task as it involves working with flammable materials. If you’re not experienced with automotive repairs, it’s strongly advised to consult a professional mechanic or technician.

However, if you’re comfortable working on your vehicle and have the necessary tools, here’s a general guide on how to make a fuel line repair:

Tools and Materials Needed:

  • Safety glasses
  • Gloves
  • Rag or paper towel
  • Safety jack stands or ramps
  • Flare nut wrench or line wrench
  • Fuel line repair kit (compression fittings, hose clamps, replacement hose, etc.)
  • Tubing cutter
  • Line wrench
  • Pliers


  1. Safety First: Ensure your vehicle is parked in a safe and well-ventilated area. Turn off the engine and allow it to cool down. Wear safety glasses and gloves to protect yourself.
  2. Relieve Fuel Pressure: Locate the fuel pump fuse or relay in your vehicle’s fuse box. Start the engine and remove the fuel pump fuse or relay to release the pressure in the fuel system. The engine will stall or stop shortly after.
  3. Raise the Vehicle: Use safety jack stands or ramps to elevate the front of the vehicle, providing access to the fuel lines underneath. Make sure the vehicle is securely supported before getting underneath it.
  4. Identify the Damaged Section: Inspect the fuel lines carefully to identify the damaged section. Look for signs of leaks, corrosion, or cracks in the lines.
  5. Remove the Damaged Section: Using a tubing cutter, carefully cut out the damaged section of the fuel line. Make clean, straight cuts on either side of the damage. Be cautious not to damage any other components.
  6. Prepare the Replacement: Measure the length of the removed section and cut a replacement piece from the new fuel line or hose. Ensure the replacement piece matches the diameter of the existing fuel line.
  7. Install Compression Fittings (If Applicable): If you’re using compression fittings, follow the instructions in your fuel line repair kit to install them onto both ends of the replacement piece. Compression fittings require specific tightening procedures, so ensure you follow the manufacturer’s guidelines.
  8. Install Hose Clamps (If Applicable): If you’re using hose clamps and replacement hose, slide the clamps onto the ends of the existing fuel line. Insert the replacement hose onto the existing lines and secure them with the hose clamps using pliers.
  9. Tighten Flare Nut Fittings: If the repair involves flare nut fittings, use a flare nut wrench to carefully tighten the fittings onto the replacement section. Do not overtighten, as this can damage the threads.
  10. Inspect and Test: Double-check all connections to ensure they are secure and leak-free. Lower the vehicle, replace the fuel pump fuse or relay, and start the engine. Check for any fuel leaks around the repaired area.
  11. Monitor and Recheck: Keep an eye on the repaired section over the next few days to ensure there are no fuel leaks. It’s essential to confirm that the repair was successful.
  12. Dispose of Old Components: Properly dispose of the old damaged fuel line components according to local regulations and guidelines.

Note: Fuel lines are sensitive components, and fuel leaks can pose serious risks. If you’re not confident in your abilities, it’s best to seek professional help to avoid safety hazards.

EVAP System Fixes

A leak in the evaporative emission control system (EVAP) can cause a gas smell. Common problems include:

  • Damaged charcoal canister
  • Faulty purge valve
  • EVAP leak

To fix these issues, you may need to:

  1. Replace the damaged canister
  2. Repair or replace the faulty valve
  3. Locate and fix the EVAP leak

Here’s how you can fix an EVAP leak.

1. Identify the Source: Use an OBD-II scanner to retrieve diagnostic trouble codes (DTCs) related to the EVAP system. This will help pinpoint the source of the leak. Common codes include P0442 (small leak detected) or P0455 (large leak detected).

2. Inspect the EVAP System: Perform a visual inspection of the EVAP system components, including the gas cap, EVAP canister, purge valve, vent valve, hoses, and lines. Look for signs of damage, cracks, disconnected hoses, or corroded parts.

3. Check the Gas Cap: Ensure the gas cap is properly sealed and tightened. A loose or damaged gas cap can trigger an EVAP leak code. Tighten the gas cap securely, and if it’s damaged, consider replacing it.

4. Check Hoses and Lines: Inspect all hoses and lines connected to the EVAP system for cracks, leaks, or disconnections. Pay close attention to rubber hoses that may have become brittle over time.

5. Check the EVAP Canister: Inspect the EVAP canister for signs of damage or cracks. If the canister is damaged, it may need to be replaced.

6. Check the Purge Valve and Vent Valve: Test the operation of the purge valve and vent valve. These valves control the flow of fuel vapors in and out of the EVAP system. Use a handheld vacuum pump to apply vacuum to the valves and check for proper sealing. Replace any faulty valves.

7. Repair or Replace Components: If you identify any damaged or faulty components, repair or replace them as needed. This may involve replacing hoses, valves, or even the EVAP canister.

8. Clear DTCs: After making any necessary repairs, use the OBD-II scanner to clear the DTCs from the vehicle’s memory. This will reset the Check Engine Light.

9. Perform a Drive Cycle: Drive the vehicle for several miles under various conditions (highway, stop-and-go traffic) to allow the EVAP system to run its diagnostic tests. This will help the vehicle’s computer verify that the EVAP leak has been resolved.

10. Retest with OBD-II Scanner: Use the OBD-II scanner to recheck for any stored trouble codes. If no new EVAP leak codes appear and the Check Engine Light remains off, it indicates that the issue has been successfully resolved.


  • EVAP leaks can sometimes be challenging to locate and diagnose. If you’re not comfortable with automotive repairs or if the issue is complex, it’s recommended to seek assistance from a professional mechanic or technician.
  • If you attempt to fix the EVAP leak yourself and the issue persists, it may be necessary to have the vehicle’s EVAP system professionally inspected using specialized equipment.
  • EVAP leaks are often related to small cracks or loose connections. Careful inspection and attention to detail are essential for a successful repair.

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Addressing Oil Leaks

An oil leak can cause exhaust fumes to smell like gasoline. Common causes are:

  • Leaking valve cover gasket
  • Damaged oil pan gasket
  • Worn-out oil seals

To resolve these issues, you should:

  • Replace any faulty gaskets and seals
  • Consult a professional mechanic if necessary

Here’s a comparison table for the common issues and their solutions:

Gas cap issueReplace the gas cap and/or o-ring
Fuel line leakRepair or replace the fuel line
EVAP system leakRepair or replace the damaged parts
Oil leakReplace the leaking gaskets and seals

Remember to follow these steps to prevent gas smells in your car:

  • Keep the gas cap tight and inspect it regularly for damage
  • Inspect the fuel lines, EVAP system, and oil seals regularly
  • Address any issues promptly to avoid worsening the problem

Preventive Measures

Regular maintenance is crucial to prevent gas smells when starting your car in cold weather. Keep an eye on your vehicle’s fuel system components, such as the fuel tank, fuel lines, fuel injectors, and fuel hoses.

It’s essential to tighten and torque your spark plugs according to the manufacturer’s specifications. Loose spark plugs may cause gas leaks, leading to smells in your cabin.

Here are some preventive measures to consider:

  • Regularly inspect fuel lines and hoses for damage or leaks
  • Replace worn or damaged components as needed
  • Keep your engine tuned to prevent running rich
  • Check the fuel cap for signs of wear or damage
  • Monitor your EVAP system for leaks or malfunctions

Performing these tasks will help maintain your vehicle’s efficiency and reduce the risk of smelling gas when starting your car in cold weather. Regular maintenance not only prevents issues but also ensures a long-lasting and reliable car.

For example:

  • Torque your spark plugs to the manufacturer’s recommendations
  • Replace your fuel cap if it’s cracked or damaged

By following these preventive measures, you can minimize or eliminate the risk of gas smells when starting your car in cold climates.

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In summary, smelling gas when starting your car in cold weather could be due to:

  • Gas leaks: Check for puddles under your vehicle.
  • Loose spark plugs: Inspect for improperly installed sealing rings.

Addressing these issues may prevent further complications and keep your vehicle safer to use. Remember to consult a professional mechanic for a thorough inspection if the problem persists.

Frequently Asked Questions

Why does my car have a gas odor in the morning?

A gas odor in the morning may be caused by a gas leak, often due to a damaged fuel tank, faulty fuel line, or defective fuel injector. Cold temperatures can also make some rubber seals and gaskets in the fuel system less efficient, allowing gas fumes to escape.

Is it normal for a car to smell like gas when it’s cold outside?

It’s not normal for a car to smell like gas in cold weather. A gas odor may indicate a leak in the fuel system or an issue with the fuel evaporative control system. Get your car checked by a professional if you notice a persistent gas smell in cold conditions.

What could be causing a gas smell inside my car?

Possible causes for a gas smell inside your car include:

  • Gas spilled on the floor or seats
  • A gas leak in the fuel system
  • Faulty seals or gaskets in the fuel system
  • Malfunctioning fuel pressure regulator
  • Issues with the evaporative emissions control system

How can I fix a gas smell in my car?

To fix a gas smell in your car:

  1. Check for gas spills and clean them up
  2. Inspect fuel lines and components for leaks or damage
  3. Replace seals or gaskets that are worn or damaged
  4. Check the fuel pressure regulator and replace if necessary
  5. Inspect the evaporative emissions control system and repair any issues

Is a gas smell in my car dangerous?

Yes, a gas smell in your car can be dangerous. Gas fumes are flammable, and a leak in the fuel system could potentially cause a fire. It also exposes you and your passengers to harmful chemicals. If you notice a gas smell in your car, get it checked and rectified as soon as possible.

Why do I smell gas in my garage when my car is parked?

A gas smell in your garage when your car is parked might indicate a gas leak, evaporative emissions system issue, or leftover gas odor from a recent spill. Inspect your car for any visible signs of gas leaks, and consider getting a professional checkup if the smell persists.

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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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