ESxxx

Thank You So Very Much for posting your solution. It solved my fairly severe front end rattle problem. I noticed that when driving my 1999 ES300 over small cracks or imperfections of small bumps on regular roads (say in an apartment complex), I could hear a rattling type noise from the front left and right side of the car. The right side was more pronounced than the left. I basically used the principle of the solution above but In my case I did not jack up the car or remove any cap or remove any bolts. Here is what i did: I bought a silicone based spray lubricant (for metal to non-metal surface contacts) from O'reilly parts store for $3.99. I tried looking for this in Autozone but could not find it there. Open the hood and from the top found the place where the strut mounts are positioned. Each of the strut mounts are on the extreme left and right side close to the passenger compartment just above where the tires are located. You can see these when you open the hood. Just look for 3 large bolts with a cup type depression in the middle with a central bolt. If you touch the inside of the cup, you can feel the rubber. All I did was spray the lubricant near around the boundary between the inside wall of the strut mount and the round-shaped rubber piece at the centre of the strut mount. I sprayed a few times changing the position of the spray each time. Basic idea was to get some of the lubricant around the surface between the rubber and metal. I did this first for the right side since that was where the problem seemed worse. After an hour or so, I drove the car and the noise from the right side was completely gone. I couldn’t believe it. I could still hear the rattling noise from the left side. So I repeated the procedure for the left side as well and the car was completely rattle free. It was an amazingly simple solution and worked wonders. Here is my hypothesis on why it works: The rubber piece between the metal contacts acts as a dampener. When it hardens, It doesn’t absorb the vibrations as well and hence the noise. Some people have complained that it gets worse in winter. I would imagine this is because of contraction of the metal parts and the hardening of the rubber. Now my thinking is that its not really the lubrication that solves the problem but rather it’s the rubber becoming supple or soft due to the lubricant and that's what solves the problem since the rubber piece is not able to act as a better absorber or metal to metal impacts or vibrations and hence dampens the noise. It did work for me. Hope it does for others with a similar issue.