All,

Long time watcher.....first time poster here. We have a 2012 LR4 HSE with 141k on it and recently had the timing chain done by a local, reputable, European specialty shop. After the repair, and immediately after cold start, there is an extremely rough idle when putting the car into reverse or drive. This generally only happens on cold start or after the vehicle has been sitting for a while. If warm, the idle is not as bad. After cold start though, the vehicle will initially idle about 1200 RPM and then drop down to 600. When I put the car in reverse, it feels like it is going to quit and it idles extremely rough. Also, when sitting at a stoplight or coming to a 4-way stop, when accelerating, there is a slight stutter and it is not smooth acceleration. This definitely did not happen before the timing chain was redone.

I am wondering whether this is a symptom of the timing chain not being installed correctly, or just an idle adjustment. Thank you for your help.

 

This is most likely related to the timing chain job if it’s started after they did the work. The engine is electrically controlled so there isn’t much of an adjustment that can be made to the idle aside from cleaning the throttle body. I’ve done quite a few of these timing jobs and the engine has to be timed perfectly or it will run rough. Also at that mileage I would have recommended replacing the tensioner, chain guides, and cam gears. It will only be a matter of time if it’s running poorly that timing related fault codes will flag in the pcm.

 

Hi Dank - Thanks for the reply and this makes sense and what I was afraid of….haha. Sorry I did not add this to first message, but the shop did also do the belts and tensioners in addition to the chain, so the whole system was done. I have read it is possible that maybe they did not connect a sensor or the air intake was put back together wrong? Most likely though, it seems to be related to a the timing chain work.

My other question would be, what do I need to tell the shop when I take it back? And, would they have to open everything back up fully to re-do the timing chain? What is necessary to adjust the timing?

 

If any connectors were not put back together the vehicle should set a DTC in the PCM after just a few drive cycles. Even if the intake being put together wrong the PCM should flag some codes for the engine running lean meaning it’s getting more air into the combustion chamber then expected. If they timed the engine wrong everything has to come back apart to retime it there’s no easy way around it. I would complain to the shop about poor engine performance since the timing job and ask them to look at it again or at least scan it for fault codes. If they timed it off a little bit there will be cam and crankshaft correlation fault codes. There’s no easy way to adjust the timing the jobs got to be completely redone unfortunately but it does happen, I’ve had to redo the process once myself.

 

Thanks again for the replies and guidance on this. This is very helpful. Just to follow up that we took the car into the shop this morning to have them double check everything. He said that when they hooked it up to the computer it was getting a mixture to Rich code error. They checked the oxygen sensors and the MAF sensors and do not think that is the problem. The tech explained that he thinks probably what happened is that when they were repairing the timing chain they have to use a special tool to pull the injectors out of the engine. He thinks one of the injectors was damaged or cracked when pulling it out so it may be stuck open and causing the fuel rich error. This sounds logical to me, but welcome thoughts. He also confirmed that after they did the timing chain replacement they did clear all of the engine adaption values and the new codes seem to indicate something other than a mis-timed timing chain.

 

Yes I agree with the technician. I’ve actually had those fuel injectors break in half while removing them you need a slide hammer to get them out. For a rich condition a damaged fuel injector could definitely cause that