Hi,
I just purchased a new to me 2011 LR4 Lux with 294,000 km at a local auction, it was listed with a rough idle and was spruced appropriately. Upon arrival the battery was fully drained and the vehicle had to boosted. I pulled a car fax and it was serviced very regularly but doesn't explicitly call out and timing chain related maintance, I did check the timing chain trough the oil filler port and it's tight.
​​​​​​ It start and runs everytime but runs extremely roughy. My obd code scanner show the follow, see attached pictures. If I give it throttle it runs pretty smooth but only over 3-4k rpm.

Any thoughts on there to start this troubleshooting, I does complain about a low battery very quickly if I have accessories on and sit in it. I have charged the battery over night. I was going to start with the easy stuff and replace the battery with a known to be good used unit out of my LR3 and reset the computer. I also constiplated it being the coils and spark plugs but I wouldn't assume they all go bad at once. However maybe it's only one or 2 that trough of the sequence.

Any thoughts are appreciated in advance.



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I just went out and checked the battery voltage which is at 12.7v non runing and 14.6v runing. That doesn't appear an issue reset the computer and cleared all engine engine cleaned both MAF sensor and throttle body. MAF sensor were very clean even before spraying them down but the throttle body was dirty. Started the engine and it's still running roughy, scanned this time with the RSW 4dscan software and got the following errors. Would could circuit F correspond to misfire on cylinder 8?

 

Bad coil trouble shoot by swapping coils and see if the problem follows the coil, battery may or may not be good but not likely the cause. These are also known to have injector failures. Would also have a look at the spark plugs, only good to about 160K km.

 

I had a similar issue on one of our 2010 RRS HSE. Mine was cylinder 6, cylinder is a little tougher to reach. I would swap the coil and maybe the spark plug first. I picked mine up from FCP Euro. Phil

 

It does appear that it's just the coil pack that was giving me grief. I moved it to a different cylinder, and the error codes followed. I ordered a new coil and will see if that resolves the issue.

On a different note, I've been keeping an eye on timing chain, inspecting it via the oil filler port throughout this troubleshooting, it's almost always nice and tight but I have found it once where it was rather loose. Does it make sense that the tightness could very depending on how it's sitting. Or does the fighting mechanism losen up if it's stationary for a while. I have no chain noise at all that I'm hearing while it's running.

 

Replaced two coils and all eight spark plugs. Runs vastly better no more engine codes, still doesn't run 100 percent smooth, hoping that will work itself in.
check out how bad these sparkplugs look, I would venture to say those were the originals.

 

hard to imagine it would run at all. those plugs are nasty. phil

 

Agreed, I have never seen sparkplugs in this shape.

Also found out that my PCV valves are damaged, which I'm hoping attributes to my slightly rough idle and lean running condition. Order news ones and will update if that addresses the issue once those are installed.