So many of you have probably been following my various issues with my LR3 (none major, but a few things don't seem right).

Today I swung by my indy mechanic (he always grills a TON of kabobs every Saturday for his customers, practically forces it on your then sends you home with more!)

Between grilling rounds he ran over with his scanner (much more advanced than anything I've got at the shop for LR) and on the top of the list was camshaft position sensor 1 and 2.

CEL was NOT on, so these were proprietary LR codes the ECM likes to store.

I'm wondering if this was a continuous fault or something that only happened the other day after my seafoam when I drove her and got the "reduced engine performance" warning combined with LOUD valvetrain noise as I hit 3500rpm. Sounded like cam angle was way off.

Would that event have been bad enough to store a fault?

I suppose if the sensors are reporting incorrect information they also could have caused that type of event to occur.

It would also explain why my power delivery is so uneven at times, usually 3/4 throttle in higher revs it'll hit flat spots then really take off.

Fuel economy, idle, and overall power are off as well, but if cam timing is off that would easily explain everything.

(My engine tick/knock thread re: single cyl. is almost certainly unrelated to this, but the slight missfire and other issues I've posted about lately could be related to this for sure).


Anyways, I didn't write down the exact fault because he was in a rush but I wish I had. I need to know if they were out of limits or what the fault actually was for. Diagnostically it's very rare for both sensors to go at the same time - sounds more like something commanded or resulted in the cams going to a location that wasn't expected, triggering the fault (perhaps my seafoam incident).

I don't think they're TOO difficult to get to, but if I don't need to replace them I'd rather not. I've tried searching for a while on here - not much luck. Is there any history of these 4.4's killing cam position sensors?

 

Really tough to say. I was just out dickin' around in my LR3..checking the charging voltage on my new AGM battery with my IIDTool to make sure the Alternator isn't over-charging it, since my Interstate batt was going tango after 8 months.

Anyway, I decided to read some codes. I found some...some soft faults I guess because I never got any indications. I cleared them and moved on. Maybe I'll look again in a few weeks.

 

Hmm found this in the OE LR workshop manual.

Almost just tempted to swap them out regardless now.

I would be absolutely shocked if something as significant as variable cam timing could be disabled without throwing a check engine light!!! wow..

Can anyone confirm if the CMP sensor failure warnings are NOT OBDII-capable codes?

EDIT: Did some more digging, nothing LR specific but on other models it'll at least disable sequential EFI and it DOES sound like it isn't an OBDII specific required code so many manufacturers keep it proprietary, which is why I didn't see it.

A generic safe / baseline ignition timing map would definitely explain a lot of my recent concerns and power loss (hopefully coincidence to my 32" wheel/tire install after all!) and poor MPG. Also probably my semi-rough idle, though hard to notice - it isn't what a "Jag" should be. Indy fired up an 06 with 200k miles (cold start) and it was smoother than mine!!!

Disabling VVT would certainly explain the peaky high-rpm power and okay low end torque as these are just inherent to the engine design - VVT is what smooths everything out and gives good power in all areas.

I really had no idea sensors like this could disable such critical components, in a "stealth" manner that might be very difficult to diagnose without LR specialized equipment.

I'll order the sensors first thing monday but carquest/napa don't have them local, LR looks to be about 4x the price. If it proves to be the sensor(s) this should for sure be a sticky! The lack of CEL (and OBDII code) and fact that the car keeps running "okay" would make this a tricky and expensive fix if a mechanic/shop just decides to start throwing parts at it.

 

Well with a basic reader I found some stored faults, but the LR readers will display something like 60-100+ faults on various modules stored from ages ago.

I'm just not sure what level these errors were on, I asked the indy a few times and he told me they were basically top-level faults on the LR-side of the ECM.

The symptoms in the LR workshop manual are just too tempting to ignore, I think I'm going to swap both out ASAP.

 

Interested to see the outcome, as I also have a rough patch at 1100rpm and have already cleaned the MAF and throttle body. I haven't really noticed any performance issues, other than what I think are more related to the transmission (sometimes a slight jab on the accelerator will send your neck snapping back, otherwise smooth as butter).

 

On my previous LR3, which had the goofy VVT fault, one of the cam sensors had a big gouge in the pickup area. I swapped it with the one from my current LR3, which I bought with a bad engine, and no difference on either one.

Not a very helpful story, I know. But the sensors are pretty easy to swap.

 

Like it ran the same after you swapped them? hm

No check engine light or anything?

 

Well the old one still got the check engine light for the vvt fault and the one with no compression on a few cylinders still ran like crap.

 

Oh haha, well that'll happen I guess lol.

I talked to my service writer who was even nice enough to bring a tech in on speaker (LR Chantilly is pretty good!) and said they'd probably replace the sensors in that situation - primarily because there isn't any clear alternative clue yet.. but also that it seemed unlikely to be the cause (between no CEL and the fact that both sensors had the code, seems more likely that a dead battery or something caused the codes historically and indy gave me a stored fault).

 

Generally the sensors aren't at fault, seen several replaced, and only one time did it fix the problem, and that had physical damage.

Was the engine noise and REP message right after you did the seafoam? Did the faults return after clearing them?

The difference between generic and LR specific faults is not the MIL being on, or a scanner being able to pull them or not, but what they mean. Many faults(generally P1xxx or P2xxx) can have different verbatims based on manufacturer, so they mean different things, and some generic scanners will not be able to understand them, but most will still show the P code.

At cold start, are you getting a loud rattling sound?

I have not seen any timing chain issues with these engines, aside from ones that were run out of oil, and I wouldn't consider those to be drivable, so I doubt you're looking at a timing issue. These VVT actuators will lock into a 0 advance/retard state(unlike the BMWs that preceded it) and will function without the use of VVT at all, but this actually lowers top end torque more than low end, so I doubt it has much to do with your 'peaky' power delivery. And yes, the MIL would turn on(after the second instance of the fault) if VVT is disabled.

Making an assumption here, but yes, Wally is fantastic on a grill, if you like spicy, be sure to make your way there when he's making burgers!