Disco 4 problems: battery, fault warnings, locking, cambelt

Disco 4 problems: battery, fault warnings, locking, cambelt

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devonian2

Original Poster:

20 posts

178 months

Wednesday 30th August 2023
quotequote all
Hello all,

We've bought a 2009 Discovery 4 with 130,000 miles on the clock and a good service history.


Questions------
- Battery strength: is 740 amps out of 900amp battery ok?
- Engine warning messages (park brake; stability control; emergency brake assist; gearbox): how to tell if these are actual faults or gremlins in the warning system?
- Central locking: won’t lock
- Cambelt replacement: what jobs to get done at the same time

So...

The above warning lights came up on the test drive, but the drive felt good, and I assumed that, because the car hadn't been driven much this year, the battery may need replacing. Perhaps foolishly, I assumed a new battery would sort the warning messages.



Battery-----

Once home, I put the battery on a trickle charger for a few days. Strangely, when setting up the charger with one cable to positive and the other cable onto bare metal in the engine area, the OptiMate 4 stayed at its initial turning on stage and didn't progress through any of the usual tests/charging cycles. I moved the second clip from the metal to the battery negative terminal (yes, I know some people recommend not doing so with Disco 4s) and then the charger happily ran through all its tests and, after leaving it for 2 days, the battery looked in great condition.

I started her up and no fault warnings: woohoo! Went for a drive yesterday to Halfords and the warnings came back a few minutes later. Arghh.

Halfords ran a battery test and said that the voltage was good, but the capacity had dropped from 900amps down to c.740 amps

I explained the above history and they did an additional battery check with the engine running, to check the charging, which came back ok (alternator = ok).

When driving home last night, I noticed that the speedo and rev counter needle lights were much weaker than I'd have expected. Don't know if they were always like that or a change on that drive.



Engine warning messages-----

These aren't always showing at startup but are always available via the steering wheel menu options. I'd say that, on the 3-4 journeys I've done, they come up every time either at startup or during the drive.

I ran my OBD2 ELM327 EOBD car code reader (https://www.ebay.co.uk/itm/266200524768), which showed no engine faults.

How can I tell which of the 4 faults are a "real" fault?

What can I do to address the faults or to remove the gremlins from the system? Some folks talk of disconnecting the battery for a short while, or is that just applicable to older Discos (I’m not sure I have the radio code, so am hesitant to go down this route right now!)



Central locking-----

I hadn't tried to lock the car since bringing it home whilst running the battery charger. In town yesterday, I tried to lock the car and, when pressing the lock button, there was only a small click from within the engine area and the doors didn't lock. When I pressed the unlock button, there was a more noticeable click (just like our Freelander 2 makes when unlocking) and it sounded as though the door unlock systems were operating.

Same problem with both keys whilst right next to the car and when 20 metres away.

Halfords tested the key fobs and said that the unlock signal on both was transmitting but weak. Same for the lock buttons’ signals.

I bought new Energizer 2032 batteries and swapped them over. No change with either key. I noticed at that point that, when 20 metres from the car, and pressing the lock button, I could just hear the weak click noise so, whilst battery may appear weak the key’s range was still pretty good.

One key is in poor condition with the sticky outer layer peeling off and the metal key part broken internally. The other key is in great condition.

Could the key problem be linked to the battery?



Cambelt-----
Last replaced September 2016 and done 33,000 miles since. Need to book it in. What should we ask a garage to do? Thinking: front cambelt (+ tensioners, + oil pump) and rear cambelt. And probably a full service at the same time for peace of mind. Anything I’ve missed out?

Our nearest independent Land Rover dealer, Mike Harding (Devon), quoted, for just the front cambelt, £1000.




Thanks to anyone who has made it all the way to the end of this lengthy post!!

And thanks for any thoughts, guidance, or experiences you’re happy to share. smile

camel_landy

5,018 posts

188 months

Wednesday 30th August 2023
quotequote all
Disco 4... Brilliant cars. smile

Batteries can cause all sorts of gremlins with these cars, so don't discount the notion of fitting a new one.

Key fobs - The strength of the signal is not going to affect the performance of the locking. If it receives a signal, it should lock. What's the performance like when pressing the (un)lock buttons on the dash?

Big Service - Gearbox oil & filter... Check the condition of the brake lines too. If they're going to take the body off for the work and you don't mind throwing some more cash at it, you could probably get the chassis cleaned & treated.

'Christmas Tree' dash lights - Does it happen at the same time you press the brake peddle? If so, try swapping the brake peddle switch out, as it's not uncommon for the arcing in the switch to cause the ECU to have a brain fart! Failing that, you're back to trying to trace it with the fault reader, etc.

HTH

M

miniman

25,852 posts

267 months

Wednesday 30th August 2023
quotequote all
Definitely change the battery, you'll be chasing all sorts of gremlins if it's weak.

Tom8

2,601 posts

159 months

Wednesday 30th August 2023
quotequote all
Interesting. On ours the coolant light warning is always on but the coolant level is always absolutely bang on. We now ignore it, been like it over a year and no one can find a fault.

Central locking a mystery to me. Our front passenger door sometimes unlocks sometimes not but will unlock once opened once!

We also get low battery warning but never had issues. Fun at the disco!

miniman

25,852 posts

267 months

Wednesday 30th August 2023
quotequote all
Tom8 said:
Interesting. On ours the coolant light warning is always on but the coolant level is always absolutely bang on. We now ignore it, been like it over a year and no one can find a fault.
Mine needed a new coolant expansion bottle to resolve that.

paintman

7,746 posts

195 months

Wednesday 30th August 2023
quotequote all
Battery not in tip top condition is the cause of many random electrical issues on later Land Rovers - not just the Disco 4.

That it works fine after fully charging but then drops off & faults re-appear points to the battery - assuming your alternator is good which you say has been tested & is.
Replace with a new battery to eliminate this as the cause.

andymadmak

14,793 posts

275 months

Wednesday 30th August 2023
quotequote all
I'd say most of your woes are battery related. Get it swapped out asap. These cars need a big healthy battery!
Cam belt should be inspected, but if it's not cracked or such like then I'd doubt it needs changing given how few miles its done since the last change. I think you could easily wait till next year for that.
Door locks/keys.... its not the keys. It will be a door lock module or solenoid somewhere. A good electrical bod should be able to sort that.
Do make sure the gearbox oil and filter are changed, or have been changed in the last couple of years

Tom8

2,601 posts

159 months

Wednesday 30th August 2023
quotequote all
miniman said:
Tom8 said:
Interesting. On ours the coolant light warning is always on but the coolant level is always absolutely bang on. We now ignore it, been like it over a year and no one can find a fault.
Mine needed a new coolant expansion bottle to resolve that.
We did that and sensor, still there.

CornishRob

256 posts

139 months

Wednesday 30th August 2023
quotequote all
You’re in prime inlet manifold split country with that mileage, assuming they haven’t been done.

Mine (2010 on 150k) has needed loads of work over the last 1-2 years, mainly just niggly bits.

But as above, get a new AGM battery for it, do a BMS reset and clear all the faults and see what sticks.


devonian2

Original Poster:

20 posts

178 months

Wednesday 30th August 2023
quotequote all
Thanks all for the brilliant replies. Much appreciated. I’ll reply to a couple about specific points.

Confusingly, I had the battery rechecked today, after two 10 mile trips, and it came back as 821amps out of 900 (ie 91%). Is it still worth replacing even though it looks so seemingly healthy?

Someone suggested fitting an AGM battery. Will that make a significant improvement in a car that doesn’t have a start-stop feature?

Whilst waiting for the battery test today, I tried locking the car. And it worked! But… it had only locked the two right hand doors. Rear left wasn’t locked and alarm was set off when opened. Front left didn’t lock either.

Then, when I unlocked the car, all the doors unlocked apart from front left, which has remained locked! Arghhh 😂

Separately, I think, I’ve spotted that all the windows open, other than rear left.

I just need to add, that other than all the above(!), the car feels great to drive (but with a fair bit of turbo lag at times - something I’ve never encountered with our Freelander 2). My kids love it. Super comfy seats. Great visibility (even with a slightly ridiculous level of tinting in the rear windows).

devonian2

Original Poster:

20 posts

178 months

Wednesday 30th August 2023
quotequote all
camel_landy said:
Disco 4... Brilliant cars. smile
I’ll check out your suggestions tomorrow 👍

devonian2

Original Poster:

20 posts

178 months

Wednesday 30th August 2023
quotequote all
Tom8 said:
…Central locking a mystery to me. Our front passenger door sometimes unlocks sometimes not but will unlock once opened once!…
Just had exactly that happen with front passenger door not locking/not unlocking!

Edited by devonian2 on Wednesday 30th August 22:41

devonian2

Original Poster:

20 posts

178 months

Wednesday 30th August 2023
quotequote all
andymadmak said:
…Door locks/keys.... it’s not the keys. It will be a door lock module or solenoid somewhere. A good electrical bod should be able to sort that…
Can anyone recommend a “good electrical bod” near Exeter?!

Edited by devonian2 on Wednesday 30th August 22:43

devonian2

Original Poster:

20 posts

178 months

Wednesday 30th August 2023
quotequote all
CornishRob said:
You’re in prime inlet manifold split country with that mileage, assuming they haven’t been done.
That sounds like an expensive job to sort out! Will trawl through the paperwork to see if it has been done…

A.J.M

7,993 posts

191 months

Thursday 31st August 2023
quotequote all
Check the battery negative terminal, there can be a date stamp on it. If it’s older than 5 years. Change it.

Locking can be down to bad door actuators. A Land Rover weakness at times, you may have ones that are on the way out.
It could also be the green wire splice under the front passenger door trim. I’ve had to cut and resoldier mine.

Cambelt change, check paperwork for auto box oil changes.
If there isn’t any, get it megaflushed.

stevewak

503 posts

135 months

Thursday 31st August 2023
quotequote all
devonian2 said:
Can anyone recommend a “good electrical bod” near Exeter?!
Blackdown 4x4 Centre are good. Servicing and sales. Kentisbeare, so not so far away. https://www.blackdown4x4.co.uk/