Strut noise (thump)

[mvbighead]

So, I had a flat tire that I needed fixed and of course they jacked the vehicle up to remove the leaking tire. Ever since that trip, it had been making a thumping sound over certain bumps. It didn't take much for this to happen.

Eventually, with the wife with me one day we both felt the sound was coming from the rear driver's side area. I jacked the car up to inspect everything, and found that the dust jacket on the strut was torn. I also had noticed what appeared to be a spot where the top of the strut may have been bumping into something at the top of the wheel well. I did my brief bit of googling and figured the strut likely needs to be replaced. It is a 2005 RX330, so it is a good 11 years old. I ordered a pair for the rear along with brakes (those are getting rather thin also), but since then...

I of course have changed nothing since, but since inspecting the car and jacking/dropping the car, the noise has stopped. It's as if something is now 'lined up' where it wasn't after first getting jacked up.

Not sure if this makes any sense to some of you, but at this point I have parts in from amazon to replace the rear struts... just not sure how urgent the matter is given that the suspension feels fine and the noise has stopped. Is this something that is somewhat common? I've jacked up numerous cars for tires/brake work, but this is the first where I have had a problem that has come and gone away since two separate instances of jacking a car up and putting it back down. The noise/no noise scenarios have been confirmed for at least 4-7 days each, so I am reasonably certain that the thumping has stopped. With and without the noise, the car ride was normal.

 

[mindless1]

It's probably not the strut itself. Well, maybe yes but probably no. If you want to call the strut the whole strut tower, it could be the spring is weak and it's (was) bottoming out. It could be that the spring seat cushion was ineffective, displaced or disintegrated. If the strut travels too far, there may also be a foam/rubber bumper in its shaft that is worn out, which comes with new struts if they had them originally.

Neither of those require replacing the strut itself. Strut only dampens repetitive bouncing of the springed weight. It may reduce travel a little but mostly it's about rebound.

Does the car exhibit excessive rebound? If so it's time to replace the struts, or if it needs springs or seat dampener, and struts haven't been replaced in a long time, might as well replace them while you have it all taken apart.

While you are fixating on struts, some other things can cause thump on bumps like broken sway bar mounts, or bushings within those mounts worn out, or the sway bar links broken or bushings worn away.

Regardless if the noise has gone away and the ride is fine, there is no urgency, but since you already have the struts, I'd go ahead and put them on if they haven't been replaced in the last ~ 40K mi, or a bit less if you often have rear seat passengers (of significant weight, not just a couple smaller children), cargo, or tow. That's if it's only ~ $100 worth of struts and you're DIY - though you may need a rear wheel alignment after installation. If it's closer to $400 worth of complete strut towers w/springs and you'd be paying someone else to install, I'd just return them for refund and order again if the problem comes back.