sf3r8z

Yesterday my 2008 ES350 would not start. Called AAA out. I believe they tested the starter and the alternator and found both good and suggested charging the battery. We assumed we left some device on and that ran the battery down although we could not think of what it was. So I charged the battery on maintenance free setting long enough that the needle quit moving towards zero and just quivered (about 4 hours). Removed charger and started engine with no problem. Took it to neighborhood parts store and had battery tested. Tested good. Wife ran her errands in it, came home, garaged and figured she must have left some electric device on the previous night.

This morning engine woud not crank, same as before. Are we going to have to take it to Lexus to get this figured out or what? I'm hoping for "or what"

jcat_350

I would take the battery out of the car as it sits, bring it to the store and have them test it. Having them test it after charging may have masked a dead cell.

If the battery tests OK when dead, next bet would be the alternator. You fully charged the battery, ran around on it, it didn't receive enough charge to crank for the next morning. I highly doubt that the AAA guy tested the starter and alternator on site, they don't have that capability.

If battery and alternator test fine, then starter is likely on it's way out. Intermittent starting is one sign of a failing starter.

If none of that ends up being an issue, it could be the crankshaft position sensor. Typically affects warm starts more than cold starts, but is likely the cause. I don't think there's a correlation to the battery in that case though, which makes it kind of odd.

garsarno

Is that your original 2008 battery?

jagtoes

Did they do a "load test" on the battery. That will tell you if you have a bad cell or if the battery is weak. If the battery is fully charged and the car starts all you need is a volt meter to see if the alternator is putting out 14V . If it stays at 12V then you have an alternator problem. If those both check out then charge up the battery and leave it disconnected over night and hook it up the next day and see if it starts. If it does then you will need to start looking for something that is drawing current with the key off.

sf3r8z

Battery results from AAA says:
Voltage: 11.47; Measured: 45CCA; Rated: 575CCA

Starter test : VOLTAGE: 10.03V ; AMPS: 0.0A; TIME: 460mS

Charging System Test: NO LOAD LOADED RIPPLE (said no problem w/charging syst)
14.03 13.93 110mV

Based on this information and the fact that after charging, the engine cranked normally, I decided, right or wrong, to buy an Interstate battery. Interstate said that one of the cells on the Lexus battery was weak. It was a free replacement from Lexus for the one that crapped out after a little over 2 years. So between the 2 Lexus batteries, I got almost 4 years.

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