Mystery creaking noise (though major parts replaced)

[NickJrv]

Hi all,

Calling on help from all the Lexus detectives out there... 🙂

I have a mystery creaking noise coming from the front (left?) of my 2007 RX350 which I'm struggling to locate in order to either fix or lubricate, depending on what it turns out to be.

It has been there since I purchased the car back in June. Since purchase I have (for unconnected reasons) replaced the following, not necessarily in order:

• All 4 air struts (I had leaks on 2 and now it is absolutely brilliant and rarely hear the compressor!)
• Front lower control arm - both were complete arm with integrated bush replacements
• Front lower ball joints, to go on the new control arms
• Rear suspension arms - both (one had a seized pin/bush, so replaced both along with cam adjusters!)
• 4 brand new Goodyear tyres with wheel balancing (had tracking done same time)
• New ARBs front and rear
• New drop links front and rear

Now, I assumed that the creaking noise (apparent over speed humps, bumps and any pot-hole/undulation in the road that would cause an up/down motion to the car) would possibly be down to one of those things (ball joints are often the culprit...). However, it is still there and very clearly so. It is hard to say if it is metallic or rubbery as the sound could be either. It's kind of like a very loud door hinge or bed spring that needs oiling, so maybe it's metallic. I did wonder if it was the ARBs being super tight and rubbing if the bar twists in them, but I'm not sure that the sound would be so persistent.

My garage chap has had it up on his ramp, had a good look and been unable to find anything untoward. He has assured me everythign is safe and stable, so this just adds to my confusion!!!

I guess now the various other suspension knocks, bumps and imperfections have gradually been sorted out, this noise is very apparent to me and anyone else in the car (or outside for that matter!) so it is top of my list of things to sort out next.

Does anyone have any thoughts or have any experience of a similar situation? I'm hoping someone may be able to help 🙂

Many thanks!

[katabrontes]

I used to get this on a tight lock on my old Toyota Surf (Japanese import of FourRunner).  It was traced to the point where the coil springs were fitted into the supporting cup.  I assume from the OP that your 300 has air suspension so this isn't likely to be your problem.  You do seem to have renewed all the potentially suspect parts.

[NickJrv]

23 minutes ago, katabrontes said:

I used to get this on a tight lock on my old Toyota Surf (Japanese import of FourRunner).  It was traced to the point where the coil springs were fitted into the supporting cup.  I assume from the OP that your 300 has air suspension so this isn't likely to be your problem.  You do seem to have renewed all the potentially suspect parts.

Thanks... it's a real head-scratcher! 🙂

[hockeyedwards]

Might drive you mad (pun intended), but maybe spray lube something you may think is causing the sound. Go for drive round the block, try recreate the noise. Rinse and repeat until you have eureka moment!

My LS had a squeak that turned out to be the drop link, took a lot of patience to find, as everything looked fine and technically was. Even when I took it off, didn't look particularly dry or damaged...

Happy lubing 😆

[Vadim]

One remaining thing to check is stabiliser bar bushes, as this is one of the parts not replaced.  Silicone spray may also help indicate issues with control arm bushes, but most other joints are sealed or difficult to access to apply spray.

 

Note that replaced parts, even if new, may cause noises as well. Especially aftermarket.

 

Some garages have suspension diagnostic stands which cause slight movement of the wheels in different directions while mechanic observes and listens from under the car. It may be worth spending sone £60 for such test.

[NickJrv]

On 10/13/2023 at 4:25 PM, hockeyedwards said:

Might drive you mad (pun intended), but maybe spray lube something you may think is causing the sound. Go for drive round the block, try recreate the noise. Rinse and repeat until you have eureka moment!

My LS had a squeak that turned out to be the drop link, took a lot of patience to find, as everything looked fine and technically was. Even when I took it off, didn't look particularly dry or damaged...

Happy lubing 😆

I've been going wild with the silcone spray, but to no avail, so guessing I've either not hit the guilty party or the problem is swatting teh spray away like flies!

[NickJrv]

On 10/13/2023 at 10:14 PM, Vadim said:

One remaining thing to check is stabiliser bar bushes, as this is one of the parts not replaced.  Silicone spray may also help indicate issues with control arm bushes, but most other joints are sealed or difficult to access to apply spray.

 

Note that replaced parts, even if new, may cause noises as well. Especially aftermarket.

 

Some garages have suspension diagnostic stands which cause slight movement of the wheels in different directions while mechanic observes and listens from under the car. It may be worth spending sone £60 for such test.

By 'stabiliser bar' do you mean the ARB? (anti-roll bar) I've done those bushes, but if you mean somewhere else I've missed then I'll definitely give it a go! 🙂

I'm now Googling garages with suspension diagnistic stands/kit 👍

[GMB]

Here's a left field approach. I had a clunky noise for two years and no-one could find the cause, checking all the bushes, suspension etc. I finally found that it was the boot lid catching the body over some bumps. Fixed.

Have a look at the bonnet to make sure that it is not moving slightly as the body may flex a little ( I know that it should not but... ). In my case, with the boot lid, the bump stoppers were doing nothing.

[NickJrv]

Thanks @GMB I'll do some "unexpected place" checking. Interestingly that was the same rattle location on my RX300! I fixed it last year. But seems fine on my RX350... the search continues... 🙂

[NickJrv]

Okay, for anyone who has had similar noises on an RX 2nd Gen, there were 2 aspects that were fixed:

1. ARB bushes - these had been replaced a couple of months ago, but (as I suspected) were tight. The bar was rubbing loudly against the inside of the bush and making teh creaking (bed spring) noise when 'bouncing' over speed humps and imperfections in the road as it flexed. It also made a slight clunk when steering left or right at slower speeds (under 5mph) so in that scenario they were grabbing the bar, then the flex would suddenly release sideways and make the slight knock/clunk (which you'd expect maybe with dodgy drop/end-links).
2. Wheel bearing (NSF) - this was actually wobbling! (vid attached) This is what I could hear make a clunk noise when I rocked the car side to side when stationary. Assumed it was related to the other (ARB) creaking. So that has been replaced.

Job done. I drove home in total silence! 👍

Happy investigating to you all 🙂

[Boomer54]

Title of the thread threw me. I wondered why are they talking about me.

[NickJrv]

Meant to say:

1. ARB bushes - greased!
2. Dodgy wheel bearing - replaced!

🙂