Good day everyone, I did a search and wasn't able to find anything concrete so I figured I would try crowd sourcing an answer or atleast get some ideas out of you guys.

The vehicle in question is a 2003 Land Rover Discovery II (North American) 4.6L V8.

Cylinders 1,3,5,7 (driver side) are all misfiring. When I did a search I found that possibly there is oil in the Crank position sensor shorting it out, or possibly MAF ?

It was fine up until about a week ago, is Land Rover known for bad grounds(corrosion) ?

Thanks for your help I look forward to talking with you, if there anymore information that you need or photos just let me know.


**Edit**
I believe I should add this pertinent information to save some questions in the future. This engine was rebuilt about 8000km ago, part of that included new plugs, wires, coils and crank position sensor along with 4 new o2 sensors.

 

Check to make sure the coil is still plugged in. If it is, then replace the corresponding coil and only use the Bosch OEM ones. None of the issues you mentioned would cause a whole bank to go bad.

 

Will do, I'll have to wait until the weekend when I have access to a garage. A little bit cold around here lately.

Thank you

 

Considering the amount of time since the rebuild hopefully the connector just wasn't fully seated and it wiggled loose rather than just bad timing on the coil failing. It can be done without removing intake but it's tight so getting back there with gloves would be tough. Good luck.

 

I am kind of dreading it lol, I have XXL glove sized hands 🤦‍♂️. I'll poke my phone / camera back there and hopefully I can see a loose connection or perhaps even invest in a cheap endoscopic camera / light (whatever they are called).

 

If the misfire is all on one bank, it seems more likely to be an O2 sensor or fuel supply issue than a coil. Each coil fires cylinders on both banks, so a failure of one coil will affect both sides.
Did you read any system codes?

 

I was thinking about that, half the bank is on one coil, and the other half is on the other coil.

Misfire stuff
P0305
P0301
P0303
P0307
P0300

And this is a new one that wasn't there before...

P0134 which is strange, this is bank 1 sensor 1 theoretically the cause of the problem. Not sure why it wasn't there before, but also... Listen to this, I was about to live stream data from this o2 sensor showing its in the right voltage range 🤷‍♂️ any thoughts on that ?

 

How quickly do the codes come back after clearing them?

 

good catch, totally had a major brain fart at work when I typed my response. My bad North, that was some bad advice.

 

Maybe 20km or less it seems.