Hey gang, Need some help from folks much smarter than I about these LR's. Sorry for the long read but want to provide all the info. I recently picked up an LR4 V8 5.0 with 70K miles on it as a fun 2nd vehicle for me. Was a good deal. Car is clean and for the first two weeks ran great. Checked all service bulletins for major issues along with car fax before buying and the VIN is outside of the scope of the timing and other known issues LR has submitted documentation for the LR4's. I took it to my mechanic (specializes in high-end vehicles as my primary car is an MB 4dr sedan) for and oil change and tire rotation. The following day, drove it on the highway for two hours one way and around town at my destination. Upon leaving late afternoon, the car started to run rough out of the blue. Nno check engine light or any warnings. Was fine all day. I turned it off let it sit a little and restarted. Drove home the 2+ hours and noticed some loss of power but again, no check engine light or any warning lights.
Took to the mechanic on this past Tuesday. The car ran ok with a little loss of power and would be rough on a rare occasion when I brought it in. As it's my 2nd vehicle, it wasn't a priority for him to get to it so he had time to troubleshoot. I have an OBD reader and checked it before he got it - no codes being reported. Seemed like bad gas or possible plugs. I filled up with fresh high octane and added fuel additive this past Monday to displace any water or poor octane rating if that was an issue.
Got the LR4 back today (Friday) after he replaced both the high pressure and low pressure fuel pumps. I got 1.5 miles to my neighborhood and went to low performance mode. I turned off and back on. Symptoms went away and no lights/warnings. I then fueled up (another $40+) as the mechanic ran through an entire tank of gas in the 4 days he had it (was full when it got there) and drove it around a while. Drove OK. Noticeable difference (increase) in power but as soon as the vehicle got warm, check engine light came on. Parked it and went to a store for about 25 minutes. Got back in and the check engine light was back on. Within minutes, the car was running rough and the reduced performance message was displayed. I slowly get it home and plug in the OBD reader.
The car seams to work fine until it's running for a bit - cold it's great. Starts right up and although rough and bucking when warmed up, never shut off. What would cause this - where should I start? I'm honestly miffed I spent a lot of money for fuel pump replacements and it's worse than when I brought it in. I'll deal with that Monday but have all weekend to mess w it now. The codes show all 8 cylinders misfire. The primary codes shown on the OBD reader are:
P0430
P0301
P0300
P0316

Plugs should be good for 100k at least but it's 9 years old and may have sat for a while before I got it. I also don't know if the former owner used high octane, midgrade, or low end fuel in it. I have only added 93 in the two weeks I have had it. Mechanic said fuel pump had been replaced at one point with an Autozone brand when he pulled it out.

What is the best way to go about this - is it to swap out plugs and test, then work way through the list of the items as listed on the LR website for the code errors? I'm already $1500 in on repairs thanks to the fuel pumps which I'm seriously questioning barely getting home in limp mode today. Just don't want to keep spending good money after bad to find the culprit.

Thoughts / Suggestions?

 

Update. After a lot of research it makes sense that the Crankshaft Position Sensor would be the culprit ie. the vehicle runs great cold and when gets to its normal temp it's a slow downhill from there. The sensor itself overheats. Based on what I have read in multiple locations, this sensor gets too hot and doesn't relay the correct information to the cat converter correctly thus the chain of events where all 8 cyl are showing misfires. Just a crappy chain of events. Does this make sense and can be the culprit? I'm an IT professional not a mechanic so looking at things in a different lens.... Working in that "If - Else" thinking mode. Thoughts?

 

Still having issues after replacing the fuel pumps (all three) fuel filter, and the crankshaft position sensor. My mechanic called a Rover shop not to far from his shop since he knows the owner and we Got a lot out of it. The Rover shop says we’re on the right path, that there is a cascade effect when something isn’t working right on these vehicles.
The recommendation was and I have seen this on the forum, is to replace the injectors. He said you can start with 4 on one side and test but should do all 8. I opted to do them all..... 🤢
The Rover shop told us that there has been an update to the injectors that were OEM in 2011 and this will clear up the issue going forward.

Fingers are crossed!

 

Same thing on my 2014 l4r would you start with the injectors did that fix it?

 

Good afternoon,

After replacing the fuel injectors and the fuel pumps. the issue reappeared after 30 miles or so. While there was a substantial amount of carbon on them, they probably would have been good just like the other components that were replaced. Here’s why I say that;

I went down a different route and eventually had to track down someone who’s very familiar with the Rovers. Found a LR mechanic that had a hunch it was something electrical rather than mechanical. He also found the previous mechanic had the air intake vent hose installed incorrectly. After a day of testing from the fuse panel back, he found a broken ground on the frame of body with a 2.6 volt drain from engine to frame. The computer in the Rover requires charging @ 14.4 volts across all connections. He fabricated a new ground and tested the connection. Boom, misfire codes, starting issue, and rough idle cleared. Like a new truck!

So, chances are I didn’t need to do the fuel pumps and again, probably not the fuel injectors. However. The rover specialist said the OEM injectors seem to always get junked up so the upgrade while not cheap was probably worth it in the long run. This vehicle only has 72K on it.

Now, because of the issues this ground wire caused, the misfires were the nail in the coffin for the catalytic converters to go bad. Both failed emission and related tests and the system is throwing P0420 and 430 codes. These are getting replaced this week. Got to love the chain reaction!

Definitely need someone who’s trained and knowledgeable with this vehicle. I really like my regular mechanic but this was unfortunately outside of their expertise and costly for both of us.

 

Hello all, new to this site, sorry for long read but I need help. I have a 2010 range rover sport hse with about 156000kms. This morning, I was on a really bumpy ramp onto the highway. When it came time to switch lanes, I got the "restricted performance" code along with a serious drop in power. I could barely maintain highway speed. Car seems to run fine while at high speed, just not a lot of power. When I exited the highway, the engine was running rough at lower speed and while waiting at a red light the whole car was shaking and idling rough. Tried turning it off and back on, no change. Upon pulling into a parking spot at low speed, the car shut off on me. Put into park and restarted, was able to park but engine still running rough and feels like it wants to choke out. I hooked my scanner up and it is saying misfire in all cylinders, misfire detected on start-up and pressure line solenoid line 5 fault short circuit. Yesterday I filled up with mid fuel instead of premium, but that's the only change I've made. Tried unplugging battery and reconnecting and also added some octane booster to try and counter the mid fuel grade. Unplugged air flow sensors and plugged back in. Still no improvement. I'm wondering if anyone has had the same problem and knows the fix? Thanks.

 

Not sure what kind of scanner you have, but wondering if you can tell whether its a misfire on all cylinders on both banks or only one? Maybe post up the actual codes. If it’s both banks, might check your fuel pressure - not sure if you’re scanner has that capability.

 

Found the issue, the dreaded timing chain. Recieved the parts today for $1000 usd and installing them this weekend.

 

Sorry to hear it. Good luck on the repair, and let us know how it goes.