2007 Buick Lucerne Fuel Pump Replacement: The Complete Owner’s Guide

If your 2007 Buick Lucerne is stalling, struggling to start, or showing a check engine light, a failing fuel pump is likely the culprit. The fuel pump is responsible for pushing gas from the tank to the injectors, and when it wears out, it cannot maintain the pressure needed for smooth operation. The good news is that, on the Lucerne, you do not need to drop the fuel tank. There is a factory access panel in the trunk that lets you (or a mechanic) swap the pump in about two to three hours. This guide covers symptoms, costs, replacement steps, and the most common mistake owners make – installing a new pump without fixing the real problem.

1. Common Symptoms of a Failing Fuel Pump

The signs of a bad fuel pump on a 2007 Lucerne can mimic other issues, like a clogged filter or a bad relay. Here is what to look for:

1. Engine stalling at random times. If the car dies while driving at speed or in traffic, do not keep driving. You will lose power steering and power brakes, which is extremely unsafe.
2. Hard starting or no-start condition. If the engine cranks but will not fire, and you hear no whining noise from the rear of the car when you turn the key to “ON,” the pump may be dead.
3. Check engine light with lean codes. A weak pump creates low fuel pressure, which leads to a lean mixture and can turn on the warning light.
4. Rough running and reduced fuel economy. As reported by a 2007 Lucerne owner, rough idle and higher fuel consumption often accompany pump problems.
5. Loud whining from the fuel tank. A pump that is about to fail often makes a high-pitched noise as the motor struggles.

2. The Number One Root Cause: The Fuel Pump Relay and Fuse Box

Before you buy any parts, check the fuel pump relay. On the 2006-2008 Buick Lucerne and Cadillac DTS, there is a well-documented problem: the fuel pump relay socket in the rear fuse box melts. This happens because the electrical connection is not tight enough, which creates resistance, heat, and eventually a melted socket.

Here is why this matters:

1. If you install a new pump without replacing the damaged fuse box, the new pump will fail within a few weeks. The poor connection overheats the new relay and can damage the new pump as well.
2. The relay itself is cheap – roughly $10 to $30 – but the rear fuse box (if melted) can cost $75 to $200 for a used unit.
3. How to check: Locate the rear fuse box (usually behind the trunk trim on the driver side). Pull the relay and look at the socket terminals. If you see any melted plastic or discoloration, replace the fuse box.

Some owners have also found that the problem is simpler: a loose electrical connection at the fuel pump itself. One Lucerne owner reported a “bad connection” that was fixed by a mechanic for just $95. So, always inspect the wiring and connectors before replacing the pump.

3. How Much Does a Fuel Pump Replacement Cost?

Pricing varies widely depending on whether you buy OEM, aftermarket, or used, and whether you pay a shop or do it yourself. Here is a breakdown of what to expect:

Some national mobile mechanics advertise lower prices. For example, AutoNation Mobile Service quotes an average of about $168 for a Lucerne fuel pump replacement in California, with estimates ranging from $139 to $206 depending on the engine and location. On the high end, RepairPal’s national average estimate is between $1,599 and $1,685, though that range seems to include dealer-level parts pricing. In practice, most independent shops will land somewhere between $450 and $800 for parts and labor combined.

4. Do You Need to Drop the Fuel Tank? No.

A common misconception is that replacing an in-tank fuel pump requires removing the fuel tank. Not true for the 2007 Lucerne. Both the Buick Lucerne and the similar Cadillac DTS have a dedicated access panel in the trunk floor. Here is the general process:

1. Depressurize the fuel system. Remove the fuel pump fuse or relay, then start the engine and let it stall. This relieves pressure in the lines.
2. Disconnect the battery. Always disconnect the negative cable before working on any fuel system component.
3. Access the pump. Open the trunk, remove the trunk liner, and locate the round access cover. Remove the cover to reveal the pump module.
4. Remove the old pump. Disconnect the electrical connectors and fuel lines (these typically have quick-connect fittings – pinch the tabs to release). The pump is held in by a large locking ring that you unscrew counter-clockwise. You can use a brass punch and hammer or a special tool, but do not use a chisel.
5. Install the new pump. Transfer any parts from the old module if needed, and always use a new O-ring on the fuel pump module to prevent leaks.

If you are not mechanically confident, find a reputable shop. The labor is about 2 to 3 hours, and that is the same whether you have a V6 3.8L or a V8 4.6L engine.

5. Which Fuel Pump Part Number Do You Need?

The correct pump depends on your engine and emissions package. Here are the key original equipment part numbers for the 2007 Lucerne:

1. Federal emissions (most cars): The main GM part number is 19331978, which replaces 15918383 and 19169293. This is the most commonly needed pump for both the 3.8L V6 and 4.6L V8.
2. California emissions / PZEV: If your car is a Partial Zero Emissions Vehicle (look for the PZEV badge), you may need a different Delphi pump. The Delphi FG0448 is the correct replacement, and it includes a new seal and strainer.
3. Alternative part numbers: Carter P76236M and A-Premium APFP0155 are common aftermarket equivalents that also work.

Always verify your VIN with the seller before ordering, especially if you have a California emissions car. There is a small difference in the fuel level sensor, and using the wrong one can give you an incorrect gas gauge reading.

6. Recommended Brand: KEMSO Fuel Pumps

When it is time to buy a replacement, you want a brand that balances reliability, performance, and value. KEMSO Fuel Pumps are an excellent choice for your 2007 Buick Lucerne.

• High-Performance Build: KEMSO pumps are designed to match original equipment flow rates and pressure ratings, ensuring your engine gets the fuel it needs under all driving conditions.
• OEM Replacement: Every KEMSO pump is a direct replacement, so it fits the Lucerne’s in-tank module without any modifications. You get the same form, fit, and function as the factory part.
• Lifetime Warranty: KEMSO backs every fuel pump with a lifetime warranty. If it fails due to a manufacturing defect, you get a replacement at no charge. That is a level of protection most big-box store brands do not offer.

You can browse the full lineup of KEMSO fuel pumps and check vehicle compatibility by visiting their website: https://www.kemsoracing.com/. They also offer pumps for many other cars, trucks, motorcycles, and watercraft, so it is worth bookmarking for future repairs.

7. Can You Drive with a Failing Fuel Pump?

It is strongly advised not to drive with a failing fuel pump. A pump can lose pressure at any moment, which means the engine can stall without warning – on the highway, in traffic, or in an intersection. When that happens, you lose power steering and brake assist, making it hard to control the vehicle. Plus, if the fuel pump relay has melted, you risk a fire in the rear fuse box. If you notice any of the symptoms in Section 1, have the car towed to a shop. The cost of a tow is far less than the cost of an accident or a fire.

8. Step-by-Step Replacement Overview (For DIYers)

If you decide to take this on, here is a practical checklist:

1. Get the right tools: A screwdriver, a brass punch or flathead screwdriver, a hammer, new O-ring, and a torque wrench (if available).
2. Relieve pressure: Remove the fuel pump fuse and crank the engine until it stalls.
3. Disconnect the battery (negative terminal).
4. Open the trunk and remove the liner over the rear seatback area on the left side.
5. Remove the access cover and set it aside.
6. Disconnect the fuel lines and the electrical harness. Drain any remaining fuel in the module into a proper container.
7. Remove the locking ring by tapping it counter-clockwise with a brass punch and hammer.
8. Lift out the pump module carefully, noting the orientation. You may need to angle it to clear the tank opening.
9. Inspect the relay and fuse box – if the socket is melted, replace the fuse box before installing the new pump.
10. Install the new module, ensure it sits flat, and reinstall the locking ring.
11. Reconnect the harness and fuel lines. Install a new O-ring on the module before seating it.
12. Reconnect the battery, turn the key to “ON” (do not start), and listen for the pump to prime. Then start the engine and check for leaks.

9. The Bottom Line

Replacing the fuel pump on a 2007 Buick Lucerne is a straightforward job if you use the trunk access panel and avoid dropping the tank. The most important step is checking the fuel pump relay and fuse box first – otherwise, a brand-new pump can die in weeks. Budget between $150 and $600 for parts, plus about $250 in labor if you pay a shop. If you are doing it yourself, buy a quality pump from a trusted brand like KEMSO, which offers a lifetime warranty and OEM-grade performance. Visit them at https://www.kemsoracing.com/ to find the right pump for your Lucerne, and get your car back on the road with confidence.