I will - I always return to the threads to share updates when I have new information. It’s just about all I can do to give back so it’s the least I can do. I’m still behind on a few things like replacing the power steering pump - it’s an on/off leak and I’ve just had a ton to do lately. I’m going to try to clean the MAF sensor today. The only thing that really worries me if the oil pump light that came on yesterday right at the last few seconds of my drive, but I think I’ll need to start a different thread for that. I had the light turn on a while ago and got some advice here I’ll refer back to as well.

 

Cleaned the MAF sensor late this evening but didn’t start it up yet. Hopefully she still runs. After that I guess I’ll see if the misfire returns but I think I have a set of spark plugs that I meant to install a while ago and a gap tool - it’s been hectic and haven’t had much time to work on the car.

I found some things while I was in there today:

MAF pipe has dried muddy water in it - probably got in through the air filter box at some point. There was some crud on the screen of the MAF that I couldn’t clean off - didn’t try brushing it since I didn’t want to mess anything up, just sprayed some MAF cleaner in it making sure to spray only in the direction away from the wires on the sensor itself.

Air filter looks quite clean still - probably haven’t even put 5,000 miles on since last installed Sept 2019. Whatever that part is just below the opening of the air intake, it’s probably a little dirty too. I tried to clean up a bit.

Dried muddy water in air intake - there was some in mass air flow pipe as well. It’s all over this engine.

Air filter looks ok - darkness is probably just an optical illusion created by the gills

Air filter looks clean Dried muddy water in air pipes - mass air flow pipe and part of air intake. I cleaned the air intake from the other side when I replaced the throttle body heater plate and took off the throttle body to clean it. I used throttle body cleaner or mineral spirits on the air intake - can’t remember now.

Air filter box has one clip missing - broken off

Crack in air filter box clip - this is the one and only clip as the other is broken off


I also cleaned the electrical connections for the MAF sensor with electronic contact cleaner. The connector didn’t seem to click back on when I was putting it back.

I haven’t started the vehicle yet, but maybe I’ll just do that now and see what happens. I plan to look into the spark plugs ASAP.

 

Well, I drove about 20 minutes up here in the mountains where I live. Full moon looking good. Saw a deer too. I was glad the car started and didn’t catch fire. So far no check engine light but the misfire only triggered the check engine light every now and then so I’ll have to drive more and see if this helps. Oil light didn’t come on this time and didn’t lose coolant and turn it into steam like last night - not sure what that was... Oil level is right at the notch in the dipstick and it’s very clean - just changed a month ago. I’ll get to the spark plugs ASAP. Thanks everyone

By the way I cleared the misfire code with the scan tool to see if it’ll come back - hopefully I can complete a drive cycle and get smogged, just tough with bad ball joints and other weird steering alignment issues that I’ll have to clear up someday - mostly difficult to do the drive cycle since it requires going above 60 MPH I believe and that’s when things get squirrelly.

 

As expected, the misfire code returned after I cleared it, so I'll try a few other things next - I'll use the Seafoam fuel injector cleaner with the next few tanks of gas and see if that helps. I'm hesitant to run the regular Seafoam (high mileage version) in the crankcase since I've just done an oil change... I guess I should have done this 100-300 miles before changing oil. I'll see if I can pull the cylinder 5 spark plug and take a look at it and the wire - might just replace the plugs at this point anyway.

Hopefully cleaning the MAF sensor did something good at least - still wondering about the dried muddy water that I guess got into the air pipes through the air box before I had replaced the air filter (late 2019) when I did some romping. I know the muck didn't get much further than the beginning of the air intake right after the MAF since I couldn't see any on the other side when dealt with the throttle body recently. I guess a snorkel would be useful there since the air filter box housing and filter seals didn't keep water or crud out - the old one at least. I didn't get too deep, but splashed up enough to get a lot of water all over the vehicle. Any input is welcome. Thanks everyone

 

How about replacing the plugs and wires? That's the most typical cause of a misfire on a single cylinder.

If you don't want to make the commitment of replacing the plugs and ignition wires before you know that's the cause of the misfire, why not swap the cylinder 5 and cylinder 6 wires and see if the misfire moves to cylinder 6? (The two wires are approximately the same length.) If it does, you have found your problem ... the ignition wire that was originally on cylinder 5.

 

if doing all that might as well do new plugs, wires and coil packs and see where you stand. It's not expensive and if swapping wires and that mess might as well just do new everything.

 

Thank you - I didn't know that was an option in troubleshooting, but it makes sense. If the misfire doesn't move to cylinder 6, but it returns after I clear the CEL again on cylinder 5, then it's more likely to be the spark plug for cylinder 5?

If I get into replacing the plugs and wires, do you have some you recommend? I'm mostly after stability and reliability, rather than high performance here since I want to get things in order primarily. I can see that I bought these spark plugs in May of 2020, but I'm not sure if I got them for the Range Rover Classic or this Discovery 2. I didn't install them in the RRC... I guess I'd know if they don't fit in the D2? I'm pretty sure I got these for the RRC, though.

 

Thanks - I'll see about all that. Do you have recommendations for plugs, wires and coil packs? I understand some of this is a little tricky?

 

I've had good luck running kingsbourne 8mm wires, coil packs are all the same I think from any of the online parts suppliers. It's not a fun replacement job but it's not terribly hard just in a uncomfortable spot to reach to. To help try airing down front tires almost all the way to lower the front end some.

 

I've had great results with STI ignition cables. I replaced mine proactively after 10+ years and 72,000 miles only because Rock Auto had a set for sale for only $11 or so. I have no experience with other brands, but it's reported on the forums that Magnecor wires, once the mac-daddy, are no longer what they used to be.

As for spark plugs, the DII has something called a wasted spark ignition system. Do an online search for more info about wasted spark systems. For long life, be sure to use double-platinum (or iridium, I'm told) plugs. The factory spec plug is the Champion 7070. It's a double-platinum, and its also referred to as an RC11 PYP B4.

Copper plugs work fine initially, but the wasted spark system causes them to physically deteriorate much faster than double-platinums, and faster than copper plugs in a conventional ignition system. Before I started caring for Redrover myself 11 years ago, a local "specialist" shop installed copper plugs. They lasted only two years and 13,000 miles before misfires cropped up.