Hey there, I’m new to the forums but have had my ‘07 lr3 for a couple of years. Please help me sort out these faults! I just replaced the drivers side spark plugs (even numbered cylinders) as a place to start to narrow down the issue (previously, I was getting a cylinder #4 misfire. I moved the spark plug to cylinder 2 to diagnosis, and the fault moved to cylinder 2, then I replaced) Most of them looked ok, maybe a little bit of orange corrosion on some, but hard to say for sure since I’m not sure what coolant would look like on there. I noticed a small amount of oil on one of the coils too. Does this seem to be a vacuum leak situation or should I be thinking about gaskets?

As far as the break switch goes, I’ve replaced the sunroof drain hose (passenger side) and will be likely doing the drivers side in the future. I would be surprised if that is related to the misfire and fuel mixture errors but if you know of quirks please let me know!

thank you for your help! I’m not sure if I actually have the repair and maintenance budget for this car (public school teacher) but I love it more than any car I’ve ever owned, despite the frustrations.

 

Since you have a 0300 code which is a random misfire, I would start be changing all eight spark plugs. Clear the codes and drive the car and see what codes reappear. As for the P0504, that is straight forward, replace the brake switch. It is basic ford part available at just about every auto parts store around, some as cheap as $25.
As for the P0174, well the wisdom of the internet says that could be caused by the worn spark plugs or any of these items:
Ignition misfiring
Intake air leaks,
Faulty oxygen sensor
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Air Flow (MAF) sensor
Incorrect Positive Crankcase Ventilation (PCV) hose connection

I think changing all the spark plugs and the brake switch will go a long way in fixing your issuews.

General Disclaimer: I might be wrong.

Let us know what you find.
Jeff

 

Thanks!! I’ll finish up the spark plugs and keep investigating. I replaced the break switch once before, but want to figure out where the moisture is coming from before I get another one.

 

Spark plugs are straight forward compared to other cars. Just make sure your socket extension is not too long as that will make it hard getting to the ones in the back. Also, you may need a u-joint or flex extension for the one in the drivers side toward the fire wall.
Moister is not the main problem with the brake switch. This "other circuit" that it controls has a higher current load to run the ABS and other terrain response things and is prone to failure faster than the one that "just controls the lights"