[GRW]

I recently had a 70K service act RAC and was advised the vehicle was idling a bit rough and probably needed the fuel filter changing. RAC advised this would need to be done a Nissan dealer. Can anyone advise why this would be the case?

 

[rogoman]

The fuel filter on your 2011 Pathfinder is part of the fuel pump assembly which is located inside the fuel tank. If it's determined that the filter is indeed plugged up, then the general replacement procedure is replacing the entire fuel pump. Most auto parts stores do not offer a separate fuel filter.

Before condemning the fuel filter, perform an ECU code readout with a portable scan tool to see if any fault codes are set. The tool can be purchased at most auto parts stores. Post the actual codes here on the forum so that we may be able to help you further. If there is one or more fault codes set, they can help point to the malfunction. If you have a copy of the FSM for your vehicle, the code readout procedure is described there along with a listing of codes. You can download a copy of the FSM from this web site: https://diyservicemanuals.com/. The section EC.PDF is the one you need to read.

The common causes for rough idle are:

• Dirty spark plugs
• Intake system vacuum leak
• Dirty fuel injectors
• Ignition coil pack

 

[smj999smj]

The way to check if the filter is clogged is to do a fuel pressure test. It's rare that they clog up unless you got a really bad tank of gas or someone dumped something in your tank. FYI, these engines normally idle a little rough by nature. The idle can be bumped up a little, which helps, but you need either a capable scan tool or a tuner (i.e. Bully Dog GT) to do so. Also, to make a note on the above post, you can rule out EGR valve as these engines don't have one.

 

[rogoman]

Thanks, made a correction on my post.