Freelander 2 (LR2) Engine hestitating when driving up an incline - Fixed

Hi everyone, this is my first time posting here and hoping for some pointers. My 2016 FL 2 2.2 diesel 100K, has an ongoing issue which started two years ago. I first notice the problem when on a motorway driving at a constant 60-70mph and the road then making a slight incline, the engine started juddering or pulsing, as if it was misfiring. Once back on a level stretch the problem stopped, also applying a small amount of acceleration during the incline, the issue again stopped. This was shortly after a yearly service, then 6 months later the fault cleared, and the engine had no issues until the next service. Following the next service ( oil and filter change + air filter) the problem started again, this time at lower engine / road speeds and driving up any size gradient. Later the fault cleared again for few months, but it's now back again and happening most days.

The issue does not show when starting from cold and while the engine is reaching working temperature. Then once the engine is hot and travelling 5-10 miles, still with no issues and the car is parked for 30 mins, the fault then appears, when started again. Often the car will not idle smoothly when stationary and in drive but is OK when neutral is selected. I have taken the LR to my local garage several times, but they have yet to see the issue and say there are no fault codes. So, I am wondering is this could be a fuel issue, poss. caused by an intermittent sensor or fuel system? As the fault clears 6 months after each service, could this be a clue that a new air filter causes the mixture to run leaner?

I am happy to buy a OBD2 reader and make recordings while the issue is present, any suggestion for best type/model would be appreciated.

Cheers Michael

Most random misfire type symptoms can be traced to a misbehaving crank sensor. However the injectors can also cause similar symptoms.
Mine went through a stage of dropping to 3 cylinders at 60-70 for a few minutes at a time, sometimes several occurrences over a 300 mile journey. I never found the definitive fault, but think it was an injector failing to inject. It seems to have stopped doing it now, although now I've mentioned it, it will probably reappear. The injectors on these engines aren't very long lived, with about 100k being normal for them.
I'd definitely be changing the crank sensor first, but only use a genuine LR replacement.

Nodge68 said:

Most random misfire type symptoms can be traced to a misbehaving crank sensor. However the injectors can also cause similar symptoms.
Mine went through a stage of dropping to 3 cylinders at 60-70 for a few minutes at a time, sometimes several occurrences over a 300 mile journey. I never found the definitive fault, but think it was an injector failing to inject. It seems to have stopped doing it now, although now I've mentioned it, it will probably reappear. The injectors on these engines aren't very long lived, with about 100k being normal for them.
I'd definitely be changing the crank sensor first, but only use a genuine LR replacement.

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Thanks for your help, would a faulty or intermittant crank sensor or injectors generate fault codes?

For my misfiring, it only happens a cirtain times, when driving up a hill at a constant speed, or when decelerating and stopping at a junction and then pulling away, it then misfires. There is oftern a noise accompanying the misfire, like a small backfire or air release under pressure.

32bits said:

Thanks for your help, would a faulty or intermittant crank sensor or injectors generate fault codes?

For my misfiring, it only happens a cirtain times, when driving up a hill at a constant speed, or when decelerating and stopping at a junction and then pulling away, it then misfires. There is oftern a noise accompanying the misfire, like a small backfire or air release under pressure.

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Crank sensors only seem to give codes when the stop working completely, but failing sensors seldom give codes.
The injectors seem to fail mechanically inside which isn't detected by the ECM, so identifying a failing injector is difficult, particularly when it's random. The only way to identify a failing injector is by substitution, which is an expensive exercise.

If you're getting noises, then it's best to check the whole air path for damaged hoses or leaking joints, as any air leaks can also generate strange running issues.

I took my FL2 to a specailist LR garage where they had a top end ECU diagnostics unit. There where no error codes but the intake air temp was 5C higher after the air filter than read by the air intake temp sensor. The fault was diagnosed as a faulty MAF sensor, after replacing the problem has been fixed. They have seen many faulty MAF sensors but they usually generate error codes.

32bits said:

I took my FL2 to a specailist LR garage where they had a top end ECU diagnostics unit. There where no error codes but the intake air temp was 5C higher after the air filter than read by the air intake temp sensor. The fault was diagnosed as a faulty MAF sensor, after replacing the problem has been fixed. They have seen many faulty MAF sensors but they usually generate error codes.

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It doesn't matter how top end the diagnostic equipment is, as it's the ECM that doesn't log the codes in the first place. Not even JLR SDD will identify codes that the ECM doesn't bother recording.

A 5°C deviation in air temperature reading is nothing, and the ECM will compensate for it in time. However there have been issues caused by the MAF, which again the ECM doesn't see.