Clunking Jackhammer sound

[Fives]

Hey y'all!

I've got a 2007 5 Sport with just under 150k miles. Here is the current problem. On take off (especially when turning) I get a clunking jackhammer sound from under the car. This tends to happen when accelerating. On occasion it also happens when accelerating over rough areas of the road. It does not happen when turning and coasting.

I had a wheel bearing issue recently and the garage that inspected the car said the sway bar bushings were fine and the struts were fine. They did mention that the both lower ball joints had a little play and were ok to pass on now but should be fixed soon. When the wheel bearing was fixed so was the lower ball join on that side of the car (passenger side).

Any ideas?

Today I came across an article that said the passenger side motor mount is a common issue with these and it sounds like that could be it but am not sure (it's under coolant reservoir and hard to see.)

Thanks.

 

[Robotazky]

Assuming you know the sound of a bad CV joint (you did check the boots right?) I would guess end links, ball joints, sway bar bushings, strut mounts; in that order.

It could be mounts. Those are easy to detect issues with. The passenger mount will be cracked and/or visibly leaking fluid. The cracks will be on top where it looks kinda like a plunger. The tranny and rear mounts show themselves by the engine rocking back and forth a lot when moving from park to drive and reverse with someone watching under the hood. You'll also probably feel some engine/tranny shifting or jerking when you press the gas pedal and/or shift into or out of gear at a stop.

You need someone who can diagnose by sound and feel to drive it or you'll just be throwing money at it.

If you had to guess a location, where is it coming from? Middle, front, side, etc? Up high or low?

 

[Fives]

A little back detail...

Had a bad wheel bearing. Took it to Shop A and was given a crazy price to fix, but they also gave me a full inspection. On the Suspension it rates Tie Rod Ends as good, Steering Rack/box and good, Springs as good, Sway Bar/Links as good, Ball Joints as poor, Struts/Shocks as fair. Being that they said the ball joints were the worst and should be addressed but were not an immediate need (the wheel bearing was an immediate need). I didn't think the Struts/Shots would be anything to worry about at 'fair'. Took it to Shop B and had the work done on the wheel bearing and the ball join for that side of the car since they game me a deal (and that much of the car was apart already).

So from what you're saying it looks like I need to focus on the other ball joint then look at the struts/shocks (based on their rating.)

For a little more on the clunk...

I do not notice any kind of vibration or movement when sitting still (even if revving the engine). This leads me away from motor mounts. When accelerating if going over bumpy or uneven roads I get the sound and a steering wheel that vibrates (short turns back and fourth quickly). The sound is from the front for sure. I want to say under the engine, kind of floor level but that could just be the easiest place to hear it from. I also feel like its more on the drive side, but again, that's where I am.

BTW, thanks for the feedback so far.

I love the car, I love that it's not the most common thing out there. I find myself wanting to talk to anyone I see see with one but never do thinking they'll think I'm nuts. It does what I need, decent milage while fitting a family of 4 and able to haul hockey equipment to and from the rink. My wife hates that I've had to fix so many things already that she think I bought a lemon (Replace 1 rim, 4 new tires, wheel bearing, ball joint) Needs drivers mirror (casing has a hole, mirror and motor are fine), AC doesn't work (doesn't show a charge when attempting to recharge, compressor doesn't activate, not sure if it's locked up or not). Typical rust on back wheel wells.

 

[mazdadude]

The most common, cheapest and easiest place to start is the Sway bar bushings... these cars eat them up. Expect 50-75,000 miles from a set..

 

[thaxman]

I speak from personal experience: Its the motor mounts. One is all the way done for and most likely at least one of the other 2 is on its way out. Revving does NOT cause vibrations. I have been through this mystery 3 times and know that for sure. My woes are documented here in at least 2 different threads.
You can purchase all 3 mounts on rockauto.com, and you can easily install them yourself. The passenger mount req. supporting the engine, the rear mount needs to have the car lifted and the engine supported, and the driver's mount is under the battery and ECM, and requires a bit more attention when taking the stuff apart and finesse during assembly, but all 3 mounts for under $150 and a Saturday to do the work makes this the biggest affordable repair I know of in the car.

 

[Robotazky]

So they say you have bad ball joints, you feel the wheel vibrating and the knocking sound on uneven pavement, yet you're not thinking the ball joint. It's the entire a-arm actually.

Sounds like ball joints or a strut mount/bearing to me. Engine mounts don't jerk the wheel on uneven pavement.

 

[Fives]

I'm slow moving on this and any other car repair (unless it to get the car back on the road). My wife likes the 'house projects' completed first. Anyway, took a look at the passenger motor mount to find there was an obvious 'tear' in the top and the inside of the mount is bone dry. This must have blown some time ago. That was the easy one to check but I'll be checking the others for sure. Thanks all.