Here is some advice from Fullfatrr.com, where more tips and fixes are available.
Power steering issue
I have driven to work this morning, no problems and no warnings then come to go out for lunch and I’ve got hardly any power steering ability.
I have checked the belts (which are only about 18 months old) on the pump and they are all fine, the fluid is at the correct level in the tank and I can hear the pump working as it normally would. If I leave the car to sit for a little bit and restart I get normal power steering for a couple of seconds then it goes really heavy, I have connected my faultmate to the car and there are no errors showing but the only thing I did notice was the servotronic PWM value remained at 0% constantly.
I recently sold my trusty v8 4.4 petrol (2002) and replaced it with a 2011 FFRR TDV8 4.4 back in April this year. A few weeks into owning the car, I began to notice a strange shudder/judder when coasting in motorway traffic, either when coming to a halt and occasionally when starting to move off again. Under load, the car drives perfectly.
This intermittent condition has slowly worsened, to the point where I took it to my local main dealer where they witnessed the issue and started off by flashing engine and gearbox ECU’s with the latest updates. If anything, it has worsened since then, they also said that there was only one fault code logged on the whole vehicle – an intermittent MAP sensor code.
It went back in to the main dealer 3 weeks later, and they had it for a further 3 weeks to investigate. They tried replacing the throttle body, had a case open with JLR directly, but 3 weeks later came back to me stating that they could not find the fault and that they would need to perform further diagnostic work (at my expense) such as removing/testing injectors, assessing whether the crankshaft sensor was playing up etc etc, all amounting to approximately 2k’s worth of diagnostic work!
The issue is now getting worse and worse, and feels as though something is going to let go soon. I have been reading up about transfer boxes potentially causing this sort of juddering, but this seems to be associated with medium to full steering lock being applied, whereas mine does this in a straight line too. Also, although intermittent in forward gears, it ALWAYS does it in reverse – whether cold/hot etc. To me, it very much feels drive line related, and does not do it when coasting in neutral (so not binding brakes etc)
I have pulled and cleaned the MAP and MAF sensors with specialised electrical contact cleaner (the MAP sensor was pretty clogged but clean now), as occasionally my idle goes from silky smooth to what almost seems to be one bank of cylinders being slightly out of sync to the other (feels like a slight but regular misfire, and the engine loses its sweet synchronised sound and wobbles a little, making a bottle of water in the drinks holder produce small waves – I am not at all sure if this is connected with the judder or not). Nothing has made any difference, and the issue continues to gradually worsen.
I thought that my torque converter was on it’s way out again, even though it was only 14,000 miles old, it has turned out to be two half dead injectors, mine only really showed up under gentle driving conditions, and the full on performance was not affected in the slightest.
If it’s your torque converter it will only manifest itself during the partial lockup stages, which on a TD6 are between 30 and 50, I would imagine that the TDV8 is at a similar speed range. I would suspect that you are having injector issues, and the only sure fire way to rule them out is to test them on an injector test rig, which will cost, I paid £17.50 per injector.
Air con issue
After about 45 minutes of driving with AC on, the car seems to decide to stop blowing air through the cabin vents leading to a very hot cabin on longer journeys, even through the blower motor is still audibly running, for some reason air flowing from face vents is severely restricted. I have tried all settings on the climate control but still this problem remains. Other websites suggest it could be the final stage resistor, but I find this strange considering that I still have full control over fan speed etc. and from cold everything is fine.
Your evaporator is Icing up. Apparently the most common cause is low refrigerant levels, and a re-gas should sort it out , only mine is in pieces at the moment so it will have to wait
There was a very strange sound intermittently coming from somewhere in the dash. It sounded a bit like a high-powered motorbike speeding past in the other direction – a fizzy, high-pitched sound. It seemed to be coming from around the area of the centre dash speaker, but it was so intermittent and short that it was hard to be sure. I have read elsewhere about ECU fans making noise, so I wondered if it might be that?
My 2012 WM had intermittent buzzing sounds from the dash. The cause turned out to be some ducting behind the dash not being fully secured. It was repaired under warranty and has not recurred.
I have a very frustrating intermittent indicator problem which also puts the park lights on and causes the battery to drain.
The RHS indicators sometimes flash without the stalk being pushed to the right. This normally happens when started up in the morning but can last up to 15 minutes. Very annoying and very confusing for other drivers! If driven every day it tends to occur less.
Mine did the same when I drowned it in a river, the BECM was underwater, was fine when taken out and cleaned and dried properly (it’s under the passenger seat by the way) My LCM did not get wet…. so I would think your problem lies within the BECM, AFAIK these have to be coded to the vehicle and I did read somewhere that you can’t recode a second hand one…. this maybe rubbish though.