The 2 Most Common Infiniti QX56 Fuel System Problems and How to Fix Them

Fuel system problems can be some of the most frustrating car issues you’ll experience. If you own an Infiniti QX56 with one of the following common fuel system problems, we’re going to help you diagnose the problem and tell you how to fix it.

Infiniti fuel system

The Infiniti QX56 can be affected by two common fuel system problems, via IFCAR

1. Faulty Fuel Tank Sending Unit

It’s fairly common for a QX56 to run out of gas even with its fuel gauge needle well above empty. Many QX56 owners say it usually happens when the gauge hits a quarter tank. The culprit behind this problem is a faulty fuel tank sending unit, a floating rod in the tank that keeps track of the fuel level and sends the information to the gauge. Infiniti issued a voluntary recall in 2010 and had its dealers replace the fuel tank sending unit free of charge.

If you suspect that you’re dealing with a fuel tank sending unit that’s not quite doing its job, you can diagnose the problem by measuring the sending unit connector’s electrical resistance with an ohmmeter. You can get a more accurate reading by draining the tank, doing a reading, filling it up, and then doing a reading again. Check your owner’s manual for the minimum and maximum specs.

If your readings don’t fall within the specs, then your fuel tank sending unit isn’t working properly. You can call your nearest Infiniti dealer and see if they’ll still honor the recall at no charge, or you can just replace the sending unit with an OEM-quality part.

2. Loose Fuel Pressure Sensor

Many QX56 owners have experienced a fuel leak, a serious problem that can become catastrophic if the leak comes in contact with an ignition source. It was soon discovered that the reason behind this common problem is the fact that the fuel pressure sensor in some QX56 units wasn’t tightened enough during production. This allows the sensor to loosen over time from heat and vibration, which in turn causes a fuel leak.

Infiniti addressed this issue by conducting a recall in late 2014 and having its dealers re-torque the sensor in affected QX56s.

While the main symptom is a fuel leak, you want to be sure that the culprit is a loose fuel pressure sensor before calling your Infiniti dealer and asking them to honor the recall. To do this, slide underneath your QX56 and gently rock the sensor to see if it’s loose.

The Importance of Using OEM-Quality Replacement Parts

When shopping for replacement parts for your fuel system, always go with an OEM-quality part. This is because they’re designed specifically to work with your year, make, and model. For example, we designed our fuel pump module assembly to exceed OEM specifications for 2007-2010 QX56s. Many aftermarket fuel pumps aren’t designed with OEM specifications in mind, so they’re prone to early failure, and they may cause problems with other parts in your car. When a fuel pump or fuel system component is OEM-quality, you know it’s good.