2005 LR3 4.4 Tonga Green.

Jumped in the LR3 and noticed a rough idle. A day later the CEL came on. It threw 4 codes, P0305 and P0316, both twice. Seems like it is likely a bad spark plug or an ignition coil. I have spent the morning checking out pricing and brands. Frankly, I don't know if the plugs have ever been changed. Truck has 138,000 miles.

Coils -

NGK makes a coil part no. U5082 $42. OEM from BP Utah $94. Any recommendations on manufacturer for the ignition coil?

Spark Plugs -

Lots of apparent choices when it comes to plugs, even from the same manufacturer. OEM number is LR005253. NGK makes several different plugs. What it the recommended brand and plug? NGK IFR5N10 $75 for a set of 8, there were also several other part numbers listed. Iridium, Iridium laser, etc. I have no idea what the OEM plugs were, (NGK OEM are $110 for the set from BP Utah). Bosch are $39. Atlantic British showed some Champion plugs as OEM.

Question, for Coil, is there a recommended brand and part number? For spark plugs, is there a recommended brand and part number?

Hopefully this will be a quick and easy fix. I will probably change out the PVC valve since I am in there and I don't recall ever changing it. Any recommendations on PVC, is aftermarket okay? BP Utah has aftermarket for $40, OEM for $75.

Thanks for the help. Phil

2005 LR3 HSE 4.4 Tonga Green 138k
2006 Range Rover Sport HSE 4.4 Giverny Green 40k
2010 Range Rover Sport HSE 5.0 Santino Black 60k

 

I swapped the coil from cylinder 5 to cylinder 3. Cleared the codes and started it up. It quickly showed a misfire at cylinder 3. Diagnosis - bad ignition coil. I checked locally and could not find a Ngk ignition coil anywhere. I ordered one on amazon $42. Only issues is that it won’t be delivered until Friday.

I pulled the the spark plug on cylinder 5. It was a Ngk iridium. Is that the original plug or have the plugs been swapped out? Looked pretty good for 140k miles. If I keep the truck I will order a set of plugs and swap them out.

Phil

2005 LR3. 4.4. Tonga Green.

 

I think NGK are indeed factory as that is also what I pulled out of mine at 120k miles and they appeared original. They looked really good and I am certain they could have handled many more miles. But I swapped to NGK 95839 Ruthenium HX. They are the latest tech and should easily go 150k miles before even thinking of changing them.

As for coils, if one goes bad there is a chance others may not be far behind. While there is no requirement to change them all at once its something you may want to start planning for.

 

Thank you. We may not keep the LR3. We have way too many vehicles. Between California registration fees and car insurance I am headed to the poorhouse! If we do keep it, plugs and coils will be on the short list. This weekend I need to replace the coil the tight front strut and maybe sway bar bushings. Phil