2010 Mitsubishi Eclipse Knocking Noise? Here's How to Fix It

How to Fix Knocking Noise

This guide addresses the frustrating knocking noise some 2010 Mitsubishi Eclipse owners experience. Often, these noises can be traced to issues within the fuel system. As one owner stated, highlighting the importance of proper parts, "My question is do any of you guys know a good place/link to get them that will fit no issues. I know Autozone and O’Rillys will often give wrong parts." - Raider_831. Let's get to the bottom of this issue.

Symptoms

The primary symptom associated with this knocking noise is, of course, the noise itself. Owners describe it as a distinct knocking, sometimes more pronounced under certain conditions. It's important to note that alongside the knocking, you might observe other symptoms related to fuel delivery.

One reported symptom, though seemingly unrelated, is rust. While rust itself isn't a direct cause of knocking, it can indicate underlying issues within the fuel system or other critical components. Rust can compromise fuel lines, leading to leaks and pressure issues that could contribute to engine knocking. One owner details a related issue: "I need a water pipe for my 1990 GST since mine is in rough shape and probably would not last long once I got it on the road. It has rust on the end where the hose would connect and other spots internal spots, In general its got bad rust issues." - Rice Burner. While a water pipe is mentioned, the underlying problem of rust is what you are looking for to be aware of.

Oil leaks have also been reported by 2010 Mitsubishi Eclipse owners. Oil leaks are potentially connected, as oil contamination can affect engine performance and potentially lead to knocking. The correlation might not be direct, but addressing any existing oil leaks is crucial for overall engine health and accurate troubleshooting.

Given the owner reports, a comprehensive diagnosis should also involve checking for any visible leaks around fuel lines and injectors. Even a small leak can disrupt the fuel-air mixture and lead to knocking. If you suspect a fuel leak, exercise extreme caution and address it immediately, as fuel leaks are a significant fire hazard.

Most Likely Cause

Based on owner reports, a likely cause of the knocking noise is issues with the fuel pressure gauge or components related to fuel delivery. Incorrect fuel pressure can cause the engine to run lean or rich, leading to combustion issues that manifest as a knocking sound. Testing the fuel injectors is a great place to start.

Improper fuel delivery due to faulty injectors will cause poor atomization, affecting efficient and even burning in the cylinders.

The presence of rust in other engine components is also worth considering, as it indicates a lack of maintenance or corrosion, which can affect the fuel system.

How to Diagnose

1. Gather your tools: You'll need a fuel pressure gauge, a basic socket set, wrenches, a screwdriver set, safety glasses, and gloves. A diagnostic scanner that can read live engine data would also be helpful.
2. Inspect for leaks: Visually inspect all fuel lines, fuel rails, and injectors for any signs of leaks. Pay close attention to areas where fuel lines connect to other components.
3. Check fuel pressure: Connect the fuel pressure gauge to the test port on the fuel rail. Start the engine and observe the fuel pressure reading. Compare the reading to the specification listed in the 2010 Mitsubishi Eclipse service manual.
4. Test fuel injectors: If you suspect faulty fuel injectors, consider testing them. Check the injector spray patterns and measure the injector resistance using a multimeter. Look for injectors with unusual resistance values or poor spray patterns. As one owner shared: "My spark plugs look good, spark plugs wires look good and both aren’t old less than 1 year. So my next step is to test my injectors to see if they’re the issue." - Raider_831.
5. Look for rust: Inspect fuel lines and components for rust.

Step-by-Step Fix

If your diagnosis points to a faulty fuel pressure gauge or issues related to fuel delivery, follow these steps:

1. Gather your parts: Ensure you have the correct replacement fuel pressure gauge, fuel injectors (if needed), and any necessary seals or gaskets. It's essential to use parts specifically designed for the 2010 Mitsubishi Eclipse. As one owner noted, getting the right parts is crucial: "It says that it fits my car but idk if it’s my error or the part didn’t actually fit. If they don’t does anybody have any recommendations for rings that actually will fit." - TortugaEclipse.
2. Relieve fuel pressure: Before disconnecting any fuel lines, relieve the fuel pressure. This usually involves disconnecting the fuel pump relay and running the engine until it stalls. Consult your vehicle's service manual for specific instructions.
3. Remove the old fuel pressure gauge: Disconnect the fuel line from the fuel pressure gauge. Use a wrench to carefully remove the old fuel pressure gauge from the fuel rail. Be prepared for some fuel spillage.
4. Install the new fuel pressure gauge: Install the new fuel pressure gauge onto the fuel rail. Ensure it's properly tightened to prevent leaks. Reconnect the fuel line to the new fuel pressure gauge.
5. Replace fuel injectors (if necessary): If you are replacing fuel injectors, disconnect the electrical connectors from the injectors. Carefully remove the fuel rail from the engine. Remove the old injectors from the fuel rail and install the new injectors.
6. Reinstall the fuel rail: Reinstall the fuel rail onto the engine. Ensure the injectors are properly seated and the fuel rail is securely fastened.
7. Reconnect fuel lines and electrical connectors: Reconnect all fuel lines and electrical connectors to the fuel injectors.
8. Restore fuel pressure: Reconnect the fuel pump relay and start the engine. Check for any fuel leaks around the fuel pressure gauge, fuel lines, and fuel injectors.
9. Test drive: Take the 2010 Mitsubishi Eclipse for a test drive to verify that the knocking noise has been resolved.
10. Address rust: Treat rust with rust remover, and replace any parts that are heavily damaged.

Parts and Tools Needed

• Fuel pressure gauge (check part numbers for 2010 Mitsubishi Eclipse specifically)
• Fuel injectors (if needed; check part numbers)
• Fuel injector o-rings and seals
• Socket set
• Wrenches
• Screwdriver set
• Safety glasses
• Gloves
• Fuel line disconnect tool (if required)

Real Owner Costs

• Fuel pressure gauge: $30 - $100 (depending on brand and quality)
• Fuel injectors (set of 4): $100 - $400 (depending on brand and if new or refurbished)
• DIY repair: The cost of parts, plus a few hours of your time.
• Professional repair: Labor costs can range from $100 to $300, in addition to the cost of parts. This will depend on the shop's hourly rate and the complexity of the repair.
• Some owners have reported spending upwards of $500 at a mechanic to diagnose and fix fuel-related knocking noises. Other owners have saved money by doing the work themselves, only spending on the parts.

Prevention

To prevent fuel-related knocking noises in your 2010 Mitsubishi Eclipse:

• Use high-quality fuel and fuel additives to keep the fuel system clean.
• Replace the fuel filter regularly to prevent debris from clogging the fuel injectors.
• Inspect fuel lines and components regularly for signs of leaks or damage.
• Address any rust issues promptly to prevent corrosion from affecting the fuel system.

What Owners Say

Real experiences from MITSUBISHI owners:

Owner Experiences

"My question is do any of you guys know a good place/link to get them that will fit no issues. I know Autozone and O’Rillys will often give wrong parts." — Raider_831 (source)

"My spark plugs look good, spark plugs wires look good and both aren’t old less than 1 year. So my next step is to test my injectors to see if they’re the issue." — Raider_831 (source)

"Here’s where the fuse is shown in the circuit diagram, between fusible link 8 and the ABS Power Relay. You must be logged in to view this image or video." — 19Eclipse90 (source)

FAQ

Q: How long does it take to fix a fuel pressure gauge issue?

A: Replacing a fuel pressure gauge can take anywhere from 1 to 3 hours, depending on your mechanical experience and the accessibility of the fuel rail. Replacing fuel injectors can add another 1-2 hours to the job.

Q: Can I drive with a knocking noise?

A: It's not recommended to drive with a knocking noise, as it indicates a potential engine issue that could worsen over time. Driving with a faulty fuel pressure gauge or malfunctioning fuel injectors can damage your engine.

Q: Is this a common issue on the 2010 Mitsubishi Eclipse?

A: While not every 2010 Mitsubishi Eclipse will experience fuel-related knocking noises, it's a possibility, especially in older vehicles with higher mileage. Regular maintenance and proactive fuel system care can help prevent this issue.

Q: DIY vs mechanic - what's recommended?

A: If you have experience working on fuel systems and are comfortable with basic automotive repairs, replacing a fuel pressure gauge and fuel injectors can be a DIY project. However, if you are unsure or uncomfortable working with fuel systems, it's best to consult a qualified mechanic. As highlighted earlier, there are some challenges with locating proper parts.