HAHA that made my day! Yeah, you are correct sir. And you're not kidding about the burgers, the ones with the green spices?

I keep telling him to open a damn restaurant or cafe or something, but no..

Thanks for the information by the way - it's nice to get some insight into how the ECM behaves with certain faults.

Are you certain about the camshaft position sensors throwing a MIL though?

I threw in the new sensors last night (and also cleaned the MAP sensor, since I was curious what they looked like at 100k+ miles.. had a small amount of dusty dirt/oil but was basically in great shape). Engine seemed to fire up easier right off the bat and idle silently/smoothly, and my MPG from last night through an hour of traffic this AM is already 2.5MPG better! The engine is DEFINITELY smooth again, so I'm about 85% certain that (per the workshop manual) all of the fail-safe modes that occur during CMP sensor failure were occurring (batch-fire EFI, disabled VVT, base/conservative ignition, etc). I really can't even tell the engine is running in neutral/park which is how I THOUGHT I remembered it, but lately it's been slightly rough even at idle.

Again this entire malfunction was so stealthy that it's easy to tell yourself nothing is even wrong at all, and it's in your head. If I hadn't seen the codes I wouldn't have thought much of it. The engine does an impressive job of fail-safe / default tuning when it loses a sensor. Apparently it can do this for almost anything including MAF, IAT and others as well?

I don't think this was due to seafoam as I did the seafoam and plugs BECAUSE my engine was rough and MPG / power were crap lately, but again everything is so subtle it's tough to put a finger on a specific time this happened, but I wouldn't do plugs unless I thought something was missing (no pun intended lol) so yeah, I think it's unrelated. The codes and MIL immediately afterwords were definitely related as you said though.

One sensor had a small ring of super fine metal dust on it where the magnet is (about the diameter of a pencil eraser) that wiped off. Otherwise not much to see.

Oh and I'm proud to say that I bought CARQUEST camshaft position sensors instead of genuine LR sensors.

Why am I proud about this, do you ask? Well, because.. the laser-etched part serial numbers on both sensors WERE IDENTICAL TO THE OE LAND ROVER SENSORS! I was kinda shocked. LR wanted about $165 for both sensors, and I got them from carquest for $50. Obviously there's only one factory out there making this specialized sensor, and that's gotta be one of the most ridiculous cases of OE markup I've ever seen. Funny story for all the "ewww you didn't use an OE part? Your car is going to blow up now" kids out there. In CERTAIN cases I'll go aftermarket, obviously sometimes they are literally identical anyways.

I'll update again later on as I drive it more. Previously the engine just seemed to be struggling to develop any decent power, with a constant slight misfire, which would be the case with a batch-fire fuel injection and base tune ignition / no VVT. I really respect VVT more as well, because during moderate accel. the engine now pulls perfectly even and smooth throughout the entire power band. I could notice the power curve was not flat before, at least now near ideal or how it should be. I can't explain it in simple terms but it wasn't very refined. It's just impressive what modern adaptive EFI and VVT can contribute to an engine design, and this was my first time experiencing this in an on/off type of manner. It's so nice now!

SO do I think everyone should go replace their CMP sensors? I don't think so - I'm really OCD about my engine and its' performance, along with every little tick rattle and squeak, but I honestly think most people would have detected that something wasn't quite right eventually, as I did.

Now if you're experiencing anything I mentioned earlier, then it's definitely worth a shot. There would also need to be some sort of stored code or indicator (though apparently not MIL) in the computer when you scan it, relating to CMP sensors.

The clearest indicator was the mileage. Yeah - it always sucks in our cars, but now I've learned that it's difficult to get it down to 12MPG. Even in stop and go traffic with my 32" tires, 19mph average speed, etc it was already at 14+MPG this morning (higher last night when I drove home without traffic obviously). I don't care about the mileage due to gas $$, it's just a good indicator about engine performance and if something has changed.

As for your question about VVT, the engine is silent on startup, save for normal "cold engine" noises, but nothing really in the heads. When the engine is really cold and I drive through 1st gear for the first time, the valvetrain gets loud as it sits around 2000rpm before it shifts. I don't remember that being such an issue before, but I'm curious if VVT being disabled may have been contributing to the noise the past couple months. Other than that I can't think of anything, except for the LOUD valve clatter I got after seafoam when it threw MIL and "reduced engine performance" on me. That was kinda scary..

Also, my driver-side VVT solenoid seems to be seeping a small amount of oil, where the plug is coming out of the valve cover... the other side is dry. It this just normal high mileage engine leak or could it be indicative of an internal leak with it? I feel like any variation of actual vs. commanded cam position would instantly throw a MIL so I'd guess the solenoid is probably fine.

Any tips for the exhaust manifold bolt access? I know almost for sure that it's leaking as it's pretty obvious when I drive next to a construction wall, especially under load.

Anything else you can think of that might cause a performance loss on a 106k mile AJ-V8? Just trying to cover all my bases while I'm at it, although I need to start tracking down the driveline scratchy/harmonic vibration in steering wheel - that sounds like it might be $$$.

 

"ewww you didn't use an OE part? Your car is going to blow up now"

 

Seriously this time, you make two statements that have curious, EstorilM:

1. SO do I think everyone should go replace their CMP sensors? I don't think so - I'm really OCD about my engine and its' performance, along with every little tick rattle and squeak, but I honestly think most people would have detected that something wasn't quite right eventually, as I did.

2. Previously the engine just seemed to be struggling to develop any decent power, with a constant slight misfire...

Per Item 1 you make this situation seem very subtle and by even asking the question of whether everyone should go out and do this you make it seem like "no big deal." Per item 2 I get a different take...if my engine was constantly misfiring (however slightly) and couldn't develop power, I'd have it diagnosed immediately!

...so I'm confused. ...and didn't you have a CEL come on as well?

 

It was subtle, and by misfire I mean at idle you can see the engine cover vibrate slightly, hard to notice in the car usually - similar to when throttle body is dirty on ours kinda. While driving the car still moves fine, it the engine's power band just didn't seem to be ideal for the gears and throttle location - it was off slightly.

I'm not talking a misfire that shakes stuff loose and causes immediate check engine light - and by power loss I'm not talking about the vehicle struggling to merge or do anything normal.

Typically I never rev the engine over 3krpm - I can literally go weeks without needing to with the traffic around here; I just baby it and the disco (2krpm for that one lol) all the time. Yes I know it's good to "blow the carbon out" of it sometimes! With that driving style it can be difficult to notice things like power curve inconsistencies, lack of power, etc.

As for the part quote, you saw me mention that they ended up being identical right? just checking lol.

 

Yeah I saw that they were identical, but that was dumb-luck on your part; you didn't buy the cheap part knowing that a priori....but anyway I was just being funny by posting that.

So, a few things:

1. I bet your LR3 HATES YOU for driving it that way.
2. A misfire sounds like a gunshot, per my understanding, but that clarification helps, thanks.

 

So MPG is still up and engine power is smoother, but the knock/tick is actually more pronounced now - see my other thread for info on that, but I'm tempted to let this one die for now. I'll update depending on what I find (if I ever do..)

Well through the shop we have warranties on everything so I wasn't concerned - plus I knew the engine would function fine without the sensors anyways.

And there can be a slight miss also, I'm talking more like if one cylinder is 140psi and the other 7 are 160 or something like that. You'll notice it, but it'll be almost impossible to track down without a compression test.

 

Well into my second week of my second LR3 and the fun has started. I have exactly the same issue as EsorilM detailed in another post and this one.

Rough idle and when I blip the throttle the RPM almost die - down to about 250. Low power as well when its like this. The fault is intermittent and I have it booked into the dealer (not LR) where I brought it for them to look into as I have a warranty for 3 months, but these threads have been very helpful.

I have a few other faults, but don't think they are related and searching the threads seems to point to different issues.

Faults are:

1. Parking sensors do not bleep. I get the fault tone when I start up the vehicle though.
2. Intermittent 'suspension fault, normal height only' - will check the wheel position between the white lines next time it happens as I read on another thread.

As I've only had the LR a week or so and have been away for most of that, I've not had an opportunity to check the things I'm seeing against some of the usual suspects - low battery, brake switch etc.

Have to do the usual things too - diff oil change, breather cap etc.

All of that said, I forgot how smooth these things ride and it makes my old Grand Cherokee seem like its had wooden wheels by comparison!

Bottom line - this site is a fantastic help and hopefully over time my own experiences can help someone else - cheers all.

 

Hey. This is the most helpful info I have in regards to my vet rattle on start up. Ive got 60k miles on my LR3 that is near mint. The shop told me I need a $7k timing chain job. What have you leaned about solving the rattle at start up?

 

How is this helpful, it's a different issue/root cause....?