hfahmy

LS600 owners,

Yesterday left my 600 running outside my garage, hybrid battery was half changed. After 15-20 mins when the battery went down to the purple two bars, I started hearing loud hum/buzz from outside and it was good 30 secs before gas engine kicked in. Did anyone experience this?

CJITTY

Nope..that's a new one for me

caha14

I have not experienced that specific scenario, but in similar circumstances, have noticed all kinds of interesting humming and other noises when the car sits and the engine cycles on and off.

Do you think you might be able to replicate and record the sound? You say the hum is 'loud', and it would be helpful to hear in order to compare to what I've heard (which some would classify as loud, and others wouldn't).

Otherwise, I take it that you haven't seen anything else that seems abnormal (for instance, the battery dropping to purple when the car is parked under "normal" conditions [i.e., not ridiculously cold outside, etc., before the engine kicks in] is not unusual)?

Vansibel

Summer or winter ? Hybrid battery does deplete pretty fast when car is left idling, so nothing wrong here. The car make a wide range of noise (not loud tough) from the outside when it switch gas/electric. Loudest I think I heard on mine is a kind of pop that sound like as if the air suspension was leveling or something. I do hear some buzzing too. And yeah, a recording of the sound would help.

hfahmy

I just tried the same thing again, this time car stayed on purple for 5 mins without the gas engine kicking in, hummed for 15 secs, hum stopped for 10 sec, the engine then kicked in. Tried to take it on video but I couldn't hear it when I replayed it. So, I can't claim it was loud. I guess I will just forget about it

caha14

To be sure, this second time around, still two purple bars (not just one)?

hfahmy

Yes, while idle, it went down to 2 purple bars, no engine for 5 mins, Hum for 15 secs, nothing for 10-15 secs, engine kick in while still two purple bars. To the contrary, When I am driving engine kicks in immediately when down to two purple bars.

caha14

Sounds in-line with my recollection (it's all I have at the moment - car has been garaged for 3 weeks due to nasty winter weather...).

It also makes sense that the engine will come on sooner when driving, since the anticipated load on the hybrid batteries is much higher than when you're parked. I have noticed that when parked, the system does tend to allow the batteries to drop more before the engine comes on.