2010 rx450h noise... I'm stressed
 

My 2010 rx450h has me stressed. Having a noise that sounds like a click/clunk when braking / accelerating through 20mph/30kph. I've been to 2 independent shops now and they don't see anything what may cause it. Both now suggesting to take it to dealer. Sound started to happen a couple weeks after the one shop replaced the water pump. Any chance they could've done damage to transmission somehow? If coasting to a stop the noise doesn't come on. Only happens when decelerating. They looked to see if suspension is loose, brakes/calipers and nothing in the obvious showing. Anyone have any tips? Scared to what the dealer may charge and if their diagnostic fee will be outrageous also. Thanks for your help/time.

How many miles? Has your brake fluid ever been changed? Have they checked for stored codes?
Have they ever serviced the brakes and lubricated the caliper slide pins to be sure they are not frozen in place? This maintenance is often ignored on hybrids.
It could be related to the brake booster or pump assembly systems. There have been some customer service programs for other Lexus hybrid models that problems with those systems. However it did not include the 2010 RX450h.

It's not likely the transmission as they are very simple on the hybrid and almost indestructible. Just change the fluid before 100,000 miles. It is an easy drain and fill, nothing like the 6 speed auto in the gas model.

Is there any chance that you can narrow down the area of noise?

Noise after work done can be due to something left loose, or even a socket that has been dropped and never retrieved. So visit the shop that did the work. If you can crawl under the vehicle you can tap the engine under shield.

Call the dealership service and tell them that there is a noise that you want them to diagnose. They will give you an estimate and it is up to you to follow through or back out.

Salim

So guys I have tried to see if noise can be replicated when slowing down in neutral and it is not.

So it only happens when in gear and decelerating around the 20mph/30kmh mark and also when accelerating from a stop.

Does this sound more like a motor mount or potentially transmission if happening when in gear?

Mounts:
Conclusive evidence is by observing engines /transmission broken/cracked mounts. They can be verified by using long levers to move the engine block.

Transmission:
Similarly noise is not conclusive evidence that transmission is bad unless there is some way to isolate the source of the noise.

Salim