Thump from hybrid (like a bass drop)

ShottsCruisers · Friday at 11:36 AM

Tangopapa said:
I am not completely convinced on the Lexus mechanics answer and want to verify.

Can someone explain how this works "IF it does this when the engine is RUNNING then I'd have somebody lube the driveshaft zerks (EASY) to eliminate that being an issue. "

The specific condition under which sound occurs is when the car is normal accelerating from a stop....and happens a fraction of a second after the vehicle starts moving (almost like something is moved by the forward momentum of the car and hitting something). This sound is different from when the engine kicks in due to autostart/stop. It occurs when engine is already running and you normal accelerate then a fraction of a second later there is a dull low volume thump sound....the sound is consistent in nature and I dont think it varies with how hard you accelerate so it is likely not being something loose in the car and bumping back due to forward momentum of the car. Normally, if something was loose, the thud timing and volume would vary ever so slightly based on how you accelerate....

But I want to understand this driveshaft zerks thing....and under the specific lens of knowing that the sound occurs just a fraction of the second after the car starts to move.

As the suspension lifts and lowers under bumps, braking, accelleration, the drive shaft moves...it lengthens and get shorter depending. Lube keeps it smooth. If there's a problem, then when you take off the shaft doesn't smoothy move. Instead it pops from one position (length) to another thus a bump or thud. And it'a a PITA.