Diagnose rattle/kncoking from front of Lexus RX. Ideas?
Discussion
I have a Lexus RX 400h (hybrid) - now 2 years old with 22,000 miles. Before it got to the 20,000 mile service, I noticed a pronounced rattle from the front driver's side of the car when driving on rough tarmac. This knocking/rattling was particularly noticeable when the brakes were applied, but not actually necessary to have the brakes on to make it happen. Going over deeps ruts/pot holes does not make the noise happen.
I took it to the Lexus dealer who kept the car for 2-3 days, driving it from cold first thing in the morning, and at different times over the course of the days. They eventually replaced the driver side drop link after identifying that it had 'play in it' that should not be there. When I took the car back, most of the rattling seemed to have gone.
A month on, and driving on the lovely rough roads of West Yorkshire, I am starting to notice a front end rattle again. I am thinking of dropping it back at the dealers to take another look at it. Finding the source of the rattle is obviously not an easy thing, but the car is still under warranty for another 12 months or so.
The rattle/knocking may be a resonant vibration when driving on coarse roads, with more weight being thrown on the front under braking (Although I say resonance - it is not a buzzing noise). The source may or may not be something inside the dashboard, but I was also wondering whether it could be something to do with the top mounts of the suspension struts.
Can anyone say whether the symptoms I am describing sound like a top mount problem? (The general direction of where the sound seems to be coming from would align with the idea).
I wish I had access to the kind of test rigs that Rolls Royce have (also seen in the current batch of Honda TV ads) where a car is placed on a special rig that bounces the car to simulate a variety of different road conditions. That would make such an investigation much easier, because as much as I could try, I can't stick my head up under the dashboard whilst driving at 30 mph (or any other speed for that matter). If fact, there is so much gubbins in the dash, it would take a well lubed gynaecologist to get even a hand up there!
I welcome the wisdom of the PH collective.
Thanks
I took it to the Lexus dealer who kept the car for 2-3 days, driving it from cold first thing in the morning, and at different times over the course of the days. They eventually replaced the driver side drop link after identifying that it had 'play in it' that should not be there. When I took the car back, most of the rattling seemed to have gone.
A month on, and driving on the lovely rough roads of West Yorkshire, I am starting to notice a front end rattle again. I am thinking of dropping it back at the dealers to take another look at it. Finding the source of the rattle is obviously not an easy thing, but the car is still under warranty for another 12 months or so.
The rattle/knocking may be a resonant vibration when driving on coarse roads, with more weight being thrown on the front under braking (Although I say resonance - it is not a buzzing noise). The source may or may not be something inside the dashboard, but I was also wondering whether it could be something to do with the top mounts of the suspension struts.
Can anyone say whether the symptoms I am describing sound like a top mount problem? (The general direction of where the sound seems to be coming from would align with the idea).
I wish I had access to the kind of test rigs that Rolls Royce have (also seen in the current batch of Honda TV ads) where a car is placed on a special rig that bounces the car to simulate a variety of different road conditions. That would make such an investigation much easier, because as much as I could try, I can't stick my head up under the dashboard whilst driving at 30 mph (or any other speed for that matter). If fact, there is so much gubbins in the dash, it would take a well lubed gynaecologist to get even a hand up there!
I welcome the wisdom of the PH collective.
Thanks
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