As I’ve read and also posted a lot on the subject of the bad vibration I and many others seem to suffer just though I would share some possibly useful information. The Mrs drives my Freelander more than me now and has recently been commenting on how bad the vibrating seems to be, so on my day off this week I thought I’d have another look and found the serpentine belt and tensioner were flapping about like crazy then when switching on air con got even worse but only a few months ago I had changed the belt and tensioner along with the bearing on the air con pump . After checking all the pulleys I found the alternator pulley was seized as it is the clutch type that only runs free one way . Got a new one from GSF same day and fitted it . Wow what a difference so smooth now and a75 mile trip experienced virtually no bad vibes at all so I think this has been on its way out for a while and finally give up . Worth checking as for £28 it’s made mine a pleasure to drive again ..

I seem to recall a reference to this pulley before in this context. Is there an obvious reason why it would produce vibration at just the narrow rev range around 1800 rpm that many of us experience?

An interesting video. Does this suggest that there might be a natural resonance around 1800 rpm that is amplified by a pulley that has seized? If one was to replace the pulley - at £28 it has to be worth a try - should the belt be replaced as well (the alternator belt and tensioner were replaced about 45,000 miles ago?

As you said this vibration has been discussed before, and suspicions around the alternator pulley clutch mentioned.
I wish that I had seen Mr Gill's excellent video before.

Also as Simon pointed out 4 cylinder engines have a natural harmonic at just above 1800rpm, and I wonder if it causes other engine/transmission to be felt around that speed. There may be more than one place from which this noise emlulates as parts/joints/etc wear with use and age.

Quotes from that thread - (I amongst the replies to TigerTim, who ran his FL2 without the belt to prove the source of his noise)

The alternator pulley has a built in one way clutch that is there to stop the fan belt oscillating in certain conditions. It can give either clicking, rattling, or slipping type of noise.

http://www.freel2.com/forum/topic21181.html

If you goggle search 'alternator pulley noise' you will find that it is common problem with lots of cars.

May be worth considering checking the pulley.

and

Just a thought.
Although the FL2 has balancer shafts built in to counteract vibration, a 4 cylinder engine has a natural frequency of about 935rpm. Various harmonics of this i.e. 1870rpm will cause the engine to vibrate. The worst vibrations are normally around 4000rpm for a 4 cylinder car.
The engine mounts should be tuned to keep the vibrations from rocking the car, unless they fail.

The following link has a link to a word document which shows the amplitude of some of these vibrations/harmonics.
https://www.maintenance.org/topic/harmonics-in-4-cylinder-engine


I think you have ruled this out by running quieter without the belt, but worth keeping in mind when looking at noise.

The original thread is
https://www.freel2.com/forum/topic31479-30.html FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Looking at that document identifying the revs at which the harmonic vibrations occur in a four cylinder engine, it certainly tallies with the FL2 problem, at 1800 rpm at least. I don’t think I’ve ever revved mine to twice that to see if it’s worse!

But it does raise the question, why does this happen to the engine in the Land Rover installation but seemingly not in Ford, Jaguar, Mitsubishi or Peugeot? It also seems to be uncommon with the manual box. Is there, perhaps, a unique LR engine or auto box mounting that is the culprit?

IanMetro wrote:

As you said this vibration has been discussed before, and suspicions around the alternator pulley clutch mentioned.
I wish that I had seen Mr Gill's excellent video before.................

On the question of harmonic vibration at 1800 rpm and then again possibly at around 3600 rpm being the culprit, I pulled to 3600 rpm in second yesterday and it was perfectly smooth. So I’m not convinced that’s the cause.

This does seem to be a problem with autos, and not with manuals, and the vibration is more or less bang on the revs for maximum torque. A torque converter issue?

A recon torque converter and solenoid valve replacement cured my vibration problem.

I seem to recall reading that. It sounds expensive - is it?

From memory around £900. Could be 7hours work by the book but specialists can do it quicker. The replacement needed 3 attempts with success on the 3rd one. They didn't charge me any extra and had the car picked up and dropped off back to me twice. Touch wood been fine for a year. now

Thanks for the info. It’s not an inexpensive exercise without certainty that it will solve the problem. Is there a way of diagnosing a failing torque converter? What exactly was the problem with it?

Shuddering at around 1600 to 1800 revs especially on going up hill. Seemed to me that the correct gear change could not occur.

I took the car in for a free test drive by an auto box specialist. He diagnosed the fault and the solution.

Mine has no issue with changing gear and it’s not noticeably worse under load. Indeed I wouldn’t go as far as to call it shuddering - more an irritating vibration. What exactly was the problem with the torque converter, given that it took three attempts to get it right?

I spoke with a local Jaguar specialist (they use the same box in some models) and he recommended a local auto box specialist who might recommend a full fluid flush. I know there’s an argument against doing that on a box that probably had 130,000 miles on it before seeing fresh fluid on the usual partial drain and refill, but I’ll see what he has to say.

Don't know what was wrong with the original TC or why it needed to be replaced three times. The gear box specialist said they had never had trouble with replacing them before, but it's now fixed and at no extra charge.

I tried doing a 3 litre change which didn't work then a complete change of fluid both done DIY at home but that didn't work either so in the end had to have the recon TC put in.

You could ask the local auto box specialist to do a test drive

Best of luck with yours