New intermittent starting issue - cranks then dies

[SuperNads]

Hi guys, my name is Nads and I'm based in Havant, Hampshire. I picked up a 2007 RX350 with 90k miles on the clock at the start of lockdown and despite being a massive Honda fan with an S2000, I've found myself increasingly obsessed with Lexus products!

I've searched around the forums but I'd appreciate any advice people have regarding a problem that has appeared today.

The car took a while to fire up this morning but it started and made a low frequency beep for 3-4 seconds on startup. No clear warning lights. After that it started normally each time I tried. When I tried the car again later on it cranked but would not start. It just sort of tailed off and died. On second attempt it started normally and after that it fires up really quickly with no noises.

I've just tried again this evening and it did the same thing where it cranked slowly then died. Again the car then behaved normally. I've tried it with 2 different keys so it's not an immobiliser issue. The car shows no signs of any engine weakness when driving and has never broken down.

I find myself doubting it's the Battery as the car has shown no gradual signs of starting poorly and is used almost every day. I'm wondering if this sounds like a crankshaft position sensor or something else. Does anyone here have experience of this happening?

Thanks,

 

Nads

 

 

[Herbie]

Could be a loose connection so as a starting point I'd disconnect both positive and negative cables from the Battery and clean up both the Battery posts themselves and the clamps that go on them too. Then go to the other ends of those cables and disconnect and clean them, along with the engine to body earth strap and make sure all connections are good and tight when you replace them.

[Lager shandy]

If your saying it cranked slowly then died .as herbie suggested with connections route etc .Also  have your Battery load tested and check starter motor connections and voltage at solenoid side .should be Battery voltage brushes could be worn heavily at 90k if a lot of stop starting in the past. I found if your getting crank / cam sensor issues when starting your more likely have warm/ hot start issues .

[SuperNads]

Thanks for the responses. I'll check the Battery - I forgot to mention the alarm has gone off randomly once or twice a week for the past couple of weeks too. Last night it decided to go off at 4am! 

There is no stop start on my model though. And it has been over 30°C for the past few days.

[steve2006]

My money is on the Battery, especially with the alarm going off randomly.