Good afternoon all, I am working on my dad’s 04 Range Rover with an M62 BMW engine, the LEDs in the dash are mostly out, but I’d suspect 150-200k miles. Started out running quite rough, low idle, no power, seemed like a text book misfire, so I replaced all plugs and coil packs. Turned on and no change in the condition.
Checked fuel pressure and was good, so I picked up a little code reader and had the entire passenger bank misfires, and P0340 plus a high and low cam sensor code, so I then replaced the cam sensors and the crank sensors, all 4 O2 sensors(the passenger upstream was wet, all the others looked good)and even threw an MAF sensor as well(yes, I know that’s wasteful, but I did it).
No change to the codes, or the running condition.
Upon further listening with a stethoscope, all the injectors are hitting, but heard some rattling coming from the passenger bank, and after reading about the vanos system, put a solenoid in it, just because I didn’t want to start replacing all of the timing components just yet.
So now, still get the P0340, as well as misfires in only the passenger bank, barely idles, doesn’t rev up, smells like un-burnt fuel, has basically no power, and I’m debating whether or not to replace the timing chains and rebuild the vanos cams, or if this is more indicative of an electrical issue.
Any and all help is much appreciated.
To add, I did look at the PCV hoses, and there was no trace of oil or anything, ran with the oil filler cracked, just to see if excessive pressure build up in the crankcase was an issue, but that didn’t change anything either. Inspected the throttle body visually, and looked pretty clean.

 

If I feather the gas pedal just right, when it’s warmed up, I can get it to rev up to 3-4K rpms, and run fairly smooth, for about 20 seconds, and then an immediate change occurs and the engine just bogs down to an idle, and can’t get it back up over 1200 rpm.