bwshell

2002 SC430 - 145k miles.

Symptom: Turn key to ON position, hear normal sounds (fuel pump, etc), turn to START and it just clicks. Turn key to OFF, then back to START, vehicle starts. Turn off/on again 5-6 times in succession (without warming up), starts with no problem. Allow the vehicle to sit for 1 hour, vehicle starts with no problem. Allow the vehicle to sit 4+ hours, issue reoccurs. This behavior is precisely consistent over the past month. Have not been driving it anywhere I have to shut if off. Now I know starters are not tied to the clock, so this thing is behaving awfully weird.

Here is what has been replaced in thus far:
Starter - Denso reman (replaced in Oct 2013 and Nov 2015)
Flywheel (Nov 2015)
Battery / battery terminals (July 2016)
Alternator (July 2016)
Starter Relay (Oct 2016)
Other things unrelated (a/c compressor, timing belt, water pump, fuel injectors, PCV, etc)

Any ideas? I hate to think I'm getting bad starters since this has now occurred 3 times over 3 years, including with the original starter that was replaced in 2013. If a short in a wire / ground, I would think power would flutuate or the starting consistency would vary. Battery is measuring 12v idle when off. Solenoid possible, but not every 1-2 years and not sure that explains the 1hr/4hr behavior unless it sticks when sitting over time.

Thanks.

Coleroad

Have you checked the ground straps

Bon

Man! That's some list of stuff that's been replaced. Is a dealership recommending this or are you doing this yourself? The flywheel?! All this has been about the starting issue? If it's so repeatable then the dealership technician should be able to diagnose without all throwing the kitchen sink at it. Have you put a stout charger on the battery and tried your starting ritual? You might also put the ground lead of the charger to chassis ground when you try this. If it start right up every time then you have a battery or grounding problem. If not then look elsewhere. I know you have a fresh battery but I never trust them until they're proved innocent.

DshngDaryl

First line of thinking:
So it only happens when it is cold?

Here is a different line of thought.
Do you have a second key you can try? Have you replaced the battery in your key lately?

Third line of thought:
Do you have techstream so you can see what kind of errors the computer has?

DshngDaryl

As an FYI.

A remanufactured Denso Starter from Amazon is like $135, but a brand new, OEM, starter from MyLParts.com is only $198 before our discount. https://mylparts.com/parts/2005/Lexus/SC430/Base?siteid=214992&vehicleid=185003&section=STARTER&group=STARTER&subgroup=STARTER&component=STARTER

Coleroad

My thought with the loose ground strap.. When the engine got warm the metal expands and tightens the connection. It was a plausible possibility, and one that was simplest to start with.

FlopTop04

Here is another thought. Any chance the ignition switch is bad? My test for those symptoms with my SC430 would be trying a remote start with the Viper remote starter. It is properly soldered to all the necessary vehicle wires and basically bypasses the ignition switch. Do you by any chance have LuxLink or some other brand of remote starter installed?

Bgw70

i agree with Cole, check those connections first.
if the terminal look like the picture, remove and clean.
try to jump start, does it still only click?