Battery maybe?

[messi]

Hi guys 

Hope your all well. 

So I only drive my ls400 twice a week, and it's been fine. Yesterday I started the car, it started first turn, then I had to go into the house to get something, so I switched it off, came back, tried starting it, and it was just a clicking noise, all the dashlights were nice and bright inside, so got the booster, attached it and waited 6mins, then turned the key, and the car started, drove and dropped my daughter off, left the car running as I thought it wouldn't start again, then drove home, parked up, switched it off, and it wouldn't start again. The Battery light didn't come on whilst I was driving though so hopefully the alternator is fine. Oh, the vsc check came on, but then disappeared, do you guys think it could just be the Battery? 

[ColinBarber]

It doesn't sound like the Battery, do you have a voltmeter to check the voltage of the Battery? Try turning your headlights on for 30 seconds, are they very dim?

Seems to be an issue with the starter motor, but certainly rule out the Battery first. 

[Malc]

2 hours ago, messi said:

so I switched it off, came back, tried starting it,

maybe just flooded the petrol run ...... probably be ok forever again ..  just don't fresh start from cold and turn off then restart shortly after again  ......  have you never noticed that with all petrol cars over the years !

I sometimes forget too but then that's my dotage 

Malc

[ColinBarber]

3 hours ago, Malc said:

maybe just flooded the petrol run

In that case the engine would turn over, just not start. Messi stated there was just a clicking noise, and I assume no engine cranking?

[messi]

Hi, 

I've just fitted a new Battery, did the reset thing, and it started and everything seems to be working correctly, I'll keep an eye on it

[Bluesman]

My son kindly changed the Battery on my LS400 today. Old one out new one in start car. Started up first time all systems seem to be working OK. Engine light on dashboard came on for about 5 secs then went off. New Battery is a Varta.

[messi]

That's the same Battery I put in mine, although it does look slightly smaller than the previous Battery, just very slightly

[messi]

But the odd thing was, the old Battery was still showing a green light, but I was told not to take too much notice of that as they are never accurate anyway 

[Cotswold Pete]

1 hour ago, messi said:

But the odd thing was, the old battery was still showing a green light, but I was told not to take too much notice of that as they are never accurate anyway 

Green light is usually saying that the Battery when not under load appears to be fine, but when you start to pull a current if some of cells start to 'collapse' then the Battery is not delivering full voltage.

I have had this happen many a time and taking Battery to local place they can see static the Battery okay, but under any load it goes AWOL, and with LS it is needing a load of oomph to get that starter motor going.

I am wondering if all the clicking that one hears are relays in the ECU(s) complaining at the same time???

 

[messi]

6 minutes ago, Cotswold Pete said:

Green light is usually saying that the battery when not under load appears to be fine, but when you start to pull a current if some of cells start to 'collapse' then the battery is not delivering full voltage.

I have had this happen many a time and taking battery to local place they can see static the battery okay, but under any load it goes AWOL, and with LS it is needing a load of oomph to get that starter motor going.

I am wondering if all the clicking that one hears are relays in the ECU(s) complaining at the same time???

 

I thought I had something major to worry about then 

[Malc]

14 minutes ago, messi said:

I thought I had something major to worry about then 

pretty unlikely with a Ls400  ,,,,,,,,,,,,,,,,   ( hopefully )

Malc

[Herbie]

6 hours ago, Cotswold Pete said:

I am wondering if all the clicking that one hears are relays in the ECU(s) complaining at the same time???

If the Battery is low enough it's more likely to be the starter solenoid doing what's commonly known as 'solenoid chatter'.

There's enough power in the Battery to energise the solenoid coil and pull in the contacts, but not enough to turn the starter motor. Battery voltage drops like a stone and the solenoid coil releases, whereupon voltage rises high enough to operate the coil again and so the cycle goes on.

[BigBoomer]

If you car stands for long periods or if you only do short trips, consider getting and fitting either a plug in Battery maintainer/charger, or else one of the solar ones. It's cheaper and way more convenient than being stranded due to a duff Battery. 

[LenT]

On 5/11/2021 at 3:33 PM, BigBoomer said:

If you car stands for long periods or if you only do short trips, consider getting and fitting either a plug in battery maintainer/charger, or else one of the solar ones. It's cheaper and way more convenient than being stranded due to a duff battery. 

It certainly sounds like a simple flat Battery.  Unless there’s some technical reason why your Lexus can’t be trickle charged, then they are a good investment anyway - even with a new Battery.  Of course that also presumes that the car’s charging system is performing correctly.

I fitted a CTEK charger to mine.  By which I mean that it comes with leads that are permanently connected to the Battery posts and are then connected to the charger by a single plug-in connector.  In fact I’ve just changed the lead to another version that includes a section with a traffic style system of leds.  So I just open the bonnet and can tell the state of the Battery charge by which colour LED is blinking.

As I say, I don’t know if your Lexus is somehow unsuitable, but it might be worth investigating.

[Cotswold Pete]

I would add from lockdown experience of having let the Battery run down four times that the Engine Managment ECU does take a while to stabilise.  What I mean is that for the first few hours of driving the car behaves like the ECU is having capacitor failure (having had a Mk3 which did have ECU on its way out), and I was getting near stalling.  But after a few decent runs the whole thing seems to settle down.  

It is now 3 months since I did a battery-out and full recharge, and all systems running like a dream in terms of RPM.  

Of course it could be other factors that cause the old lady to stabilise after flat Battery which had been flat for a month or so each time.

[ColinBarber]

28 minutes ago, Cotswold Pete said:

Of course it could be other factors that cause the old lady to stabilise after flat battery which had been flat for a month or so each time.

Older Toyota/Lexus vehicles take a while to learn idle points, fuel trims etc. after an ECU reset (from a Battery disconnection or ECU fuse pulled). They seem to need the vehicle to move/stop/go into neutral/park multiple times as part of the correction process which is why you notice it takes a few runs to sort out.

[BigBoomer]

Mine has spent the last year plugged into a Battery maintainer and it's done it no harm.
Just remember to design in a weak link that won't short circuit either the charger or the car, just in case you drive off without disconnecting it, oh and fit an inline fuse between the Battery and the connector,.... just in case. Mine is fused at 10A.
A friend fitted a 20W solar cell to his rear parcel shelf and wired it in via a relay so it's only charging the car when the ignition is off.
His XJ4.0 has been parked most of this year and still starts like he last drove her yesterday.