Discovery 4 - Throttle fault. Help!

Discovery 4 - Throttle fault. Help!

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CBH

Original Poster:

1 posts

97 months

Thursday 4th February 2016
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I recently bought a 2011 Discovery 4 from Stratstone Cardiff under the 'Land Rover approved scheme'. It has so far not been a good experience (dead battery after a week, knackered exhaust after two weeks, satnav/AV system black-screening for days at a time among other issues). I will keep my views on Stratstone for another forum, but suffice it to say I would never purchase a car from them again. Customer service is not their strong suit.

However, the major issue I have had is a 'phantom' throttle fault. Harwoods have had a crack at it and could not diagnose it and Stratstone have now had the car for a full week and tell me that "they can't fix what they can't find" and have basically said that its my problem.

I wonder if anyone else has had the following fault, or has any suggestions. The fault manifests itself as follows:

Every few hundred miles or so when traveling at a steady speed the car will suddenly begin to lurch violently with the throttle pulsing on, off, on, off, on, off. As if I was repeatedly and very rapidly stamping my foot onto and then off the accelerator pedal. This usually continues for about 5 to 10 minutes before everything returns to normal. It first occurred when I was doing 70mph on the M25 and it is quite a scary experience. It has also occurred at slower speeds. Over a 2 month period it has happened about 6 times in total.

When the fault is occurring, if I put my foot to the floor and accelerate, the car will accelerate smoothly without any problem, but as soon as I start to maintain a steady speed the 'bunny-hopping' will start-up again. Inversely, if I take my foot off the accelerator and press the brake, the cars motion smooths out straight away.

The fault first occurred when I had cruise control on, but has since been when I have my foot on the throttle, maintaining a uniform speed. The car has always had more than half a tank of fuel when the fault happens.

No warning lights have appeared at any stage and both Harwoods and Stratstone tell me that nothing shows up when they plug the car into their 'machines'.

Given the way the fault manifests itself it doesn't sound to me like a fuel issue. My best guess is a glitch with the electronic throttle...

Has anyone else had this issue? Or does anyone have any suggestions, either with what might be wrong with the car or how to deal with Stratstone who have refused to either investigate further or take the car back.

Thanks in advance

IroningMan

10,154 posts

245 months

Friday 5th February 2016
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You should post this in the D4 Technical forum on www.disco3.com.

camel_landy

4,863 posts

182 months

Friday 5th February 2016
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Be careful... If you ask the 'Armchair Experts', you may well get some useful advice but you'll also be off on wild goose chases!!

Under the 'Land Rover approved scheme', you'll have a warranty: Use it!

  • Take it back & get them to sort it.
  • Try using a different dealer.
  • If you feel strongly enough about the (lack of) service, complain to Land Rover.
As for the fault itself, remember these cars are 'fly-by-wire' these days. Chances are there's a fault with the throttle potentiometer as just needs replacing.

M

PeterY27

136 posts

105 months

Friday 5th February 2016
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My Range Rover did a similar thing when I first got it, I found driving hard for a few tanks of fuel with an injector cleaner added and it cleared after 5k miles.

Mine had sat around for quite a while not being driven before I got it and put it down bad fuel and just having to get it out of the tank. Done 20k miles since and not had an further issues.