i started experienced this lately. first thought was the battery, had it checked by Autozone, battery's fine. i will take my car in next week. what usually causes the unusual long cranking during start? starter? alternator? this is a '09 IS350 with 74k miles. also, if i try again after one of those long cranking start, it went back to normal.

 

Are you on the original factory battery? If so, you might as well get a new one to fully cancel that item off of the list. Then I would look at wiring, then the starter itself.

 

i just had it replaced 6 months ago at the dealership.

 

^Well, I'd check out the battery wiring...especially the negative ground wire where it attaches to the chassis. I've read that a few members had their start to become loose or corroded, thus causing starting issues.

Next would be the actual starter not engaging the "teeth" or perhaps the solenoid going bad.

 

^^^ thank you for the advise. come think of it, i had the battery changed out 1.5 years ago and it was completely dead a year after that and that was when i took to dealer and they swapped out the battery 6 month ago. at the time i specifically asked them were the hardware battery is attaching had issues since i just replaced it not too long ago, they said no, just a bad battery. let's see what they say this time because the battery level is fine.

 

The battery needs to be tested under load. Make sure you are checking voltage when the starter is running.

 

sounds like battery to me I don't trust Lexus batteries, tested under load as stated earlier.

 

today is the 2nd day after i dropped the car off, still waiting on technician getting back to my SA on the slow starting issue. it was difficult to duplicate the issue which i agree, only happens about once every 10 starts. but they did rule out the battery, it was tested and deemed fine. currently there's a recall on the 2IS for fuel pressure sensor leaking, anyone heard of that? they're waiting for parts for that, so looks like i get to drive the ES300h loaner for couple more days.