Suspension Noise (Yes, another thread)

[Ars Gladius]

This has been driving me nuts for the last few months. I have knocking when going over bumps, worst between 20 km/h and 80 km/h on rough roads. Not to prevalent over 80 km/h, but it's faintly there. Under 20 km/h, no real noise unless the road is really rough.

Sounds like it is coming from the front end, can hear / sorta of feel it through the floor in the front foot-wells. Which would lead me to think sway bar bushings end-links?

I (and my mechanic) have checked the front suspension; ball-joints, bushings (control arms and sway bars), control arms, tie rods and end-links all look good and tight. Entire front suspension was replaced last year; all Volvo (everything else), OEM (springs) or IPD (sway-bars, spring seats) parts.

Here is an MP3 of the sound (it's in a gravel parking lot with pot holes, so lots of knocking for you): https://drive.google.com/file/d/0B6IxboRFynfmZE1GWFVxLVczd28/edit?usp=sharing


Thanks for any suggestions.

[Volvoholic]

Did you replace the rubber suspension mounts at the top of the springs too?

Sometimes, if those wear out super badly, that will lead to space in the top of the springs under expansion which could lead to thumping.

[Ars Gladius]

Did you replace the rubber suspension mounts at the top of the springs too?

Sometimes, if those wear out super badly, that will lead to space in the top of the springs under expansion which could lead to thumping.

It's more of a knocking than a thumping. The audio quality is not that good, my phone seems to be making it more muffled than it actually is.

Yep, everything was replaced for the front suspension with new parts (strut bearing, spring seats, bump stops, dust bellows, springs, struts, ball joints, end-links, sway-bars, washers, nuts, control arms, etc).

As the noise seems to be coming from the floor area and sorta seems to be on both sides of the car, I am leaning towards the sway-bar bushings and/or end-links despite the fact that they look fine. I think someone mentioned a while back that their end-link looked fine until they took it off the car and then found out it had a lot of play in it.


I'll have to start doing part replacement I guess (which is not too bad as I'll start with wear parts that will eventually have to be replaced anyway so I'm not wasting money, just my time).

[TheDarkKnightt]

End links can still be "tight" to the hand when you go to check them, depending how the car is sitting even though they may be worn out.

Did you replace both inner and outer tie rod ends?
Just because parts were replaced last year, doesn't mean that one of the parts might have been defective.

One other thing- check the top torque bar mounts where they go to the frame. I had one separate the core and it caused a lot of bumping and never could figure it out until one day I pulled up on the bar. Just a suggestion.

Take off your roll bar and see what happens. If that's it, get the IPD- pricey, but bushing are replaceable.

[madbill683]

Thanks for starting this thread. My '07 with 71,000 miles has been making the same noise. I replaced the strut bearings and spring mounts (HD) in Jan 11 when I bought the car. I just ordered Lemforder end links and will try to replace them this weekend. They fely fine by hand, I figure it's time, we have horrible roads here.

[men2be]

Ars, just for grins, check the top "cross" nut on the struts. Take a large drift and tighten it with a hammer. Had that on mine. Seemed tight but was not.
Hope it works!



QUOTE=Ars Gladius;168369]It's more of a knocking than a thumping. The audio quality is not that good, my phone seems to be making it more muffled than it actually is.

Yep, everything was replaced for the front suspension with new parts (strut bearing, spring seats, bump stops, dust bellows, springs, struts, ball joints, end-links, sway-bars, washers, nuts, control arms, etc).

As the noise seems to be coming from the floor area and sorta seems to be on both sides of the car, I am leaning towards the sway-bar bushings and/or end-links despite the fact that they look fine. I think someone mentioned a while back that their end-link looked fine until they took it off the car and then found out it had a lot of play in it.


I'll have to start doing part replacement I guess (which is not too bad as I'll start with wear parts that will eventually have to be replaced anyway so I'm not wasting money, just my time).[/QUOTE]

[vtl]

(random guess) Check subframe bushings?

[Ars Gladius]

Thanks for all the suggestions, I have or I will / I am starting work through them. Will keep post updated.

[Volvoholic]

Sounds like this is one of those mystery noises like how my front left wheel groans coming back to center from full left lock. But only left lock.

[madbill683]

Thanks for all the suggestions, I have or I will / I am starting work through them. Will keep post updated.

Well, I replaced both of my end links, and the rhythmic thumping noise is still there. The driver side link had to be destroyed for removal, as the lower nut was spinning and the hex was stripped out. I think I'll try the top engine mount next. Might go with the poly bushing.

[JRL]

Don't, unless you want more vibration(s)

[madbill683]

Don't, unless you want more vibration(s)

JRL,

I read some old posts, and did NOT order the poly mount. I ordered the Hutchinson parts from fcp. I don't know if those parts will fix the thumping or not. Possibly LCAs are next, or struts, even though my indy says struts last a long time, and are only bad when they are leaking. I wish I could let you test drive the car. No uneven tire wear or pull or wander though.

Bill