Member Since: 18 Mar 2022
Location: Cardiff
Posts: 11
Rough Idle and Flickering Lights
Hi
2007 D3 took a little while longer to start the other evening. Once it did fire up it idled for a little while then the RPM suddenly started ramping from low idle up to near 900 RPM repeatedly, whilst this was happening the headlights, cabin lights were pulsing in time with the RPM ramping, the radio was also intermittently working.
I thought this maybe the alternator. I checked voltages on the battery and battery reads 12.2 volts, when running with lights and radio on it peaked at 14.8, there wasn't a huge amount of change when alternating the the revs up to 2000rpm it floated between 14.3 - 14.8. So I wondered if this is the alternator after all. The belt and tensioner all seems ok, I've not taken the fan out to have a proper inspection though.
When inspecting today, I did see the the rear injector on the passenger side is leaking, there is a pool of fuel around it. Could this cause the RPM ramping I saw, which I guess would cause the lights to flicker.
New to LR's and keen to learn more about tackling these tasks myself. Alternator and Drive belt seems like an easy ish task.
18th Mar 2022 4:37 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4809
12.2 volts is too low as a starting voltage you want to see 12.6 or above. However first things first, if you have a fuel leak you need to deal with it immediately as it poses a fire risk. It may just be the leak off pipe but if it's the injector it will affect the engine.
Once that's sorted and the battery is fully charged/renewed see how the behaviour is then. Having the fault codes read will reveal any issues, but do not ignore that fuel leak!! yµ (idµ - eAµ) ψ=mψ
18th Mar 2022 5:38 pm
cfcjim
Member Since: 22 Jun 2010
Location: Munich
Posts: 65
Your alternator may be on the way out.
Mine had the same pulsing symptoms at idle, seemed to be charging perfectly, lasted for about a month or so, then just gave up about 3km from my office.
19th Mar 2022 10:20 am
M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8146
More like the battery or poor earth, 12.2 volts indicates a flat battery, although a faulty alternator could cause a major battery drain.
I would try a jump lead from the battery earth terminal to the engine block and see if it makes any improvement, after you have cured the fuel leak.It can when others can't,
It will when others won't,
It goes where others don't.
19th Mar 2022 2:08 pm
hdc101
Member Since: 18 Mar 2022
Location: Cardiff
Posts: 11
Thanks for the info. I’ve got it booked in to get the injectors looked at. I’d rather get those done by a professional as the access is a bit tricky, I also don’t have the correct tools to pull them out if troublesome. I ordered a Denso alternator and new drive belt, going to try and attempt this myself as my first foray into home mechanics. The voltage on the battery had dropped again overnight, all keep an eye on it and see what happens, worst case I have a spare alternator.
I got the vehicle a few months ago and have been catching up on its serviceable items since. Hoping to plan a big trip in the vehicle but worried I’ve made a bad choice with the LR and it’s reliability, I do love it though even after spending 1700 on a new HPFP and fitment. A always feel a sense of sadness as something goes wrong but at 83k I keep going with it, hoping that the problems will become less frequent! They will won’t they!?
19th Mar 2022 3:02 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4809
That's very low mileage for a HPFP, injectors, and an alternator to fail! If it's been there for a few years or more replace the battery and keep a genuine brake light switch in the glove box.
Don't use non LR mechanics or garages for maintenance. It will be a learning curve for them to familiarise with these vehicles and it's you who will be paying for the tuition! Independent LR specialists only and stay away from the dealers too.
Breakdown cover is a very wise move if you are intending on long journeys. yµ (idµ - eAµ) ψ=mψ
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