It was cylinder 3 initially, NOT cylinder 4. Huge oops, sorry. I was really distracted when I wrote that initial thread, my wife and kids were all over me and we were getting ready for my son's first birthday party that was about to commence, and I was meanwhile trying to be a loving father and husband while having an internal meltdown.

So two more updates on my drive home to clarify things some more:
1. Forget the O2 sensor idea. Sorry for the wild goose chase. Before my drive home, I crawled under my Disco and tried to clean some gunk off that O2 sensor with gloves and cleaning wipes from the hospital I work at. And I realized what an idiot I am for not having at least touched it earlier—the "Frayed" part is just the sleeve, which moves up and down. The wires are fully intake. All I had to do was wiggle it to see that... don't know what I thought was copper there.
2. I swapped the fuel pump relay, just for fun, but it didn't change anything. On startup tonight, the engine stumbled a little to get going before taking off. So it's still not "back to normal." Hawkeye ready, I saw a dozen misfires on cylinder 7 during startup, but nothing like this morning. Then I scrolled up and saw some misfires on cylinder 3.

So Cylinders 3 and 7 are both misfiring. I'll bet yesterday I just wasn't being observant enough to look closely at cylinder 7 readings to see that it was misfiring too, but today anyways, cylinders 3 and 7 were both misfiring. Here's the crazy thing though, after startup and a few misfires, it only had a couple misfires all the way home, 10 minutes through town with multiple stop lights where I sat in hot idle. I drove normally to see what it would do, without doing the neutral/brake thing, and it just had a couple low-rpm misfires here and there, but no, "This thing's gonna blow up!" shaking at low rpms. To note, there was one moment halfway through the drive where it felt slightly rougher than normal as I started slowing down for a light, but it just threw a few misfires, nothing awful.

I arrived at my home and sat in my driveway for five full minutes at hot idle. I just sat there and watched the Hawkeye misfire readings. The Rover averaged three misfires in a minute on cylinder 7, and I felt them very mildly. There were zero misfires on cylinder 3. I don't understand how at home at hot idle I had no massive shuddering, while yesterday it was catastrophic feeling.

One more note... now that I know what a misfire "feels" like from actually seeing it happen on the Hawkeye and then feeling it in my seat and correlating the two, I realize that over this last year, the Rover HAS been having some intermittent misfires, I just didn't know what it was. ALSO, last summer, I put in some fuel injector cleaner because it was running a little rough on startup. I can't believe I forgot that... I just dismissed it of course, because the fuel injector "cured" it and I thought, "Great, I put that fire off for another day..." Well, I wonder if this is now that day, when the fire is burning a lot hotter.

Maybe the accident didn't actually cause this? Maybe the heat of the summer has something to do with it? Which leads me back to head gaskets...

I feel like I'm going crazy. I drove the car for three days after getting it back from the body shop who did all the repairs, and it drove well... no massive shuddering, but maybe a little dismissible shudder here and there. Then all of a sudden it no starts and this all happens... No matter what, I know 1 thing: It's got something serious going on, because it's struggling to start every time and that's not good.

There is minimal coolant loss, as far as I can tell (expansion tank seems good anyways), some oil leakage that looks to be from valve cover gaskets but that's been ongoing and I've been intermittently dealing with it. I wonder though if there is a head gasket leak on the driver's side... No overheating. It gets up to 208F sometimes under heavy driving, but usually stays in the upper 190 or low 200s. I don't like it but haven't been able to figure out what to do to bring it down. Thermostat replaced about three years ago. New reservoir cap and even new coolant tank because of a leak.

So cylinders 3 and 7 are on the same side of the block, and on the coil pack they are not connected, as far as I understand how coil packs work, though I don't really understand them much.

humroot — I was hit on the driver's side but it was more middle-back, and didn't affect the front side of the door. Only between the front and back door, and more to the back, because it even busted my rear tire. Though the fusebox is a plausible idea. Hey, did an ARB Front Winch Bumper really save you when your truck when you hit a deer??

 

Oh my god, yes it did. I was on the highway going to work and doing 70. Damn deer jumped right in my lane and I know better than to swerve, so I hit it dead center at 70. The crush cans that came with the bumper absorbed most of the impact. The bumper pushed back into the hood and the light tabs went all the way through the hood. The only damage to the bumper was the crush cans and a dent below the winch. It did bend the front fender a little and the headlight and they still don’t look right. If I didn’t have that bumper with the brush guard, I’m sure the deer would have come over the hood (after destroying the front end) and through the windshield. It was a big deer. The hit was so hard the cup holder and both coin drawers opened. I drove it right to work after that and continued to drive it for months until the new crush cans were delivered by ARB from down under.

You mentioned a little coolant loss. I had misfires on 6 and 8 and headgaskets fixed it. You can check your coolant for exhaust gases with a kit from autozone...it’s a free rental. If you do the headgaskets, I HIGHLY recommend using the ARP studs.

 

No worries, still, those cylinders aren't next door neighbors though it's moved into the slightly more likely category.

1. I suspected that might be what you were seeing, there's often a white woven cloth sheath on my vehicles that frays, covered with oil, it can be hard to determine what you're looking at.
2. It's not uncommon to see things clean up on a hot engine vs a cold one. Compression pressure is better for one thing when it's hot.

I'm not sure what has caused the changes nor the cause of what's occurring so it's hard to speculate with any accuracy. I'd say check the plugs and do a compression test, those two things will rule a lot out at least. Unless you wish to mess around with ignition items which is the likely culprit but can be a lot of circling endlessly to chase down the problem.

The misfire feels like a hiccup under load, most noticeable on a slight hill usually. Now that you know the feeling, you'll spot it for life in any car right away. A FEW are normal, plenty of vehicles do it a few times a day and it's no big deal. If it's been occurring it could be a matter of the issue just being progressed by what happened OR there's a chance that the crash had nothing to do with it and we're on to a separate issue. <Edit> < I see you are onto that same point now that I'm reading further on your response>

You might be right about the fire burning hotter about now but if that was the fix, it might be fixable again. You could certainly try a little SeaFoam. https://landroverforums.com/forum/di...ons-dii-20730/ Do make sure you limit how quickly it drinks it and do it with the engine a little warmed up but not quite full temp, just let it idle two minutes before you do the seafoam to minimize thermal shock, limiting how quickly it gets sucked into the intake also limits thermal shock. You can also add it to your fuel tank, I'd suggest doing it when you're quite low on fuel because it doesn't take so much seafoam and after you're done, you can top off fuel and not be driving around seafoaming all week. This will get it through the injectors where as sucking it up the intake will clean out your intake path. I don't put a lot of weight in this fix but I've seen it clean up gunked motors and improve things quite a bit for a year or so.

You could have cracked/broken plugs.... that'll cause issues like you're describing, in fact, when I pulled my plugs I had one that was fractured! Go figure but it was on the cylinder that was fine and well but still would become an issue if it hadn't already started to.

The struggling to start thing is indeed a bad sign sure but it would likely be related either way so it doesn't say much for us ruling things out.

Check the oil, confirm it isn't milky, if it's been siting, you can drain a little from the plug, the water will sit on the bottom below the oil. It's an excellent sign if you're not going through coolant or overheating!

I don't know these coils well either, so I won't speak to that.

So, since we went in circles a little:
1. Check plugs, photos would be great showing the plug tip that is in the motor, we're looking for oil,wetness,overly clean, dust,color,broken ceramic insulators.
2. Plugs are out and a compression tester is Free to borrow from Autozone or $13 bucks on Amazon..... it's good idea to do in general on vehicles.
3. Get a "block tester" from Autozone, it's free as is the fluid. You'll put it on the coolant container, give it a couple minutes of running and then give it a bunch of squeezes and see if it turns yellow, if it does.... you're $#@%ed. <EDIT> Humroot beat me to it. >
4. Seafoam fuel system and intake through breather if you wish to give it a shot for a few bucks
5. Continue to search for electrical issues.

Bear in mind, FUEL/IGNITION/COMPRESSION is what makes an engine go, one or more of these is lacking, we just need to pin it down.

-Greg

 

Holy hell!!!

How'd he taste?

 

I'm more curious about the white woman cloth sheath... Pictures or it didn't happen.

 

LOL! Let me correct that "White + WOVEN + cloth + sheath" Good find

 

Any photos of vehicle after crash pre-body work? Photo of body work done, photo of interior fuse panel? O2 sensor will cause a misfire if stuck in full rich condition, however your plugs will be black and sooty, possibly wet.

 

Sorry for dropping off for a few days, it's been a crazy week. Here's the semi-resolution:
I just ran out of time to work on the Disco, and we need it back sooner rather than later, so I took it to my trusted small service shop that has always done a good job for me before. They did a thorough diagnosis and came up with failed coil packs! That was like music to my ears—no pistons, piston skirts, head gasket, bent rod etc.

I changed out the plugs and wires 30,000 miles ago with magnecor's and champions, but they said they were fouled up, which makes sense if it's been misfiring for a long time, so I gave them the go ahead to swap those out again. So ignition coils to plugs all will be new.

And on top of all that, they found that both my engine mounts are destroyed. I guess the wreck could have helped that along, but at 145,000 miles, not too surprising.

Being great service providers, they let me source my own parts, which saved me a couple hundred. The engine mounts and coil packs I got from Lucky8—$52 for a set of 2 coil packs there, versus $90 EACH from other suppliers, like Atlantic British. Similar story for the engine mounts, much cheaper at Lucky8. I even saved a few dollars on the upper intake manifold gasket getting it from Lucky8, where it was only $8 instead of like $13 at AB.

Once I get the truck back and actually drive it, I'll know for sure, but I have hope. I'll repost when it's all over.

 

Final resolution: Coil packs were to blame!

It runs better than it has in ages. I think I gradually came to accept little misfires here and there over the last year or so, and only when it really crapped out a few weeks ago did it catch my attention. Amazing what you come to accept as "normal" with a Land Rover. But boy, I feel like this thing could run forever with how smooth it starts, idles, accelerates and drives.

I'm sure new engine mounts helps with overall smoothness too...

Note on my experience with Lucky8: One of the 2 coil packs from them was defective. My shop installed both coil packs, then found new misfires and tested the coil pack to find one of them was defective. They had to disassemble again, get a new coil pack (I had them get one locally for expediency) and reinstall. So those "cheap" coil packs from Lucky8 cost me over $100 in extra labor, a much more expensive local coil pack, and caused several more days of inconvenience for my family, being without a second car. Not too happy with Lucky8 over this and will reconsider purchasing from them in the future.

Thank you all SO much for advising me through this stressful ordeal. To have this NOT be a bent rod, blown head gaskets, or other big engine problem makes me almost giddy. My 4-year-old daughter has been asking for weeks to ride in the Land Rover again, and my wife and I are thrilled to finally be able to get back to driving it.

Also, thanks Best4x4 for correcting the title thread.