Engine won't turn over once engine is warmed up
 

So I have had this issue with my 07 GS350 for about a month now, and the shop it is currently at is actually having an issue recreating the problem (of course.)

As title says, car starts/engine turns over when it has been sitting for >1 hour. Every morning and evening before/after work, starts with no problem. If I stop at the grocery store on the way home, the car won't even attempt to start. I have to let it sit and try again once it has cooled down. Further information below.

- Starter/Alternator/Battery have all been tested, as well as the connections and wires.
- No codes are being thrown, currently, but cannot further test until the shop can recreate the problem.

Going back and forth with a couple people, we have theorized that something within the car (brain, electrical) is telling it to not even attempt to start due to something being too hot. I am not sure where to even start with this theory. Cat? O2 sensors?

Any information or ideas on how to possibly diagnose this is greatly appreciated.

When it is acting up and you try to start it, does the starter spin at the normal speed? Or does is drag slower?

It doesn't sound like the starter spins, at all. I get a quiet hum (not sure if this is the starter or not) for about 10 seconds, followed by nothing.

Could be a neutral safety switch problem. How was the starter tested? If it fails when hot that is not something that can easily be replicated on the bench.

Sounds like your starter gear shaft is binding the gear that engages the starter. You can remove the starter clean that shaft and lube it really well. Also a good idea to slap in new contact brushes while youre at it.


Look at 2:06 see how that gear is sliding into position. I believe yours is not sliding and just spinning giving you that humming sound.

Also when it acts up the engine doesnt turn over, is that correct?