SOLVED: LOUD Thumping Noise When Turning (possibly NOT CV joint)

Hey Everyone - I’m new here and I have a problem…

I bought a used 2009 Subaru Impreza wagon, 2.5i NA, manual trans a month or two ago. I’m in Texas and only recently it’s started getting fairly hot (above 90 during the day). I mention the temperature because the thumping noise I’ve noted when turning only seems to appear after the car heats up, or when I have been driving it for a good 30 or so minutes. I’m not sure if it’s the car heating up or the heat of the day. Either way it doesn’t make the noise right as I start driving (in the morning when it’s cooler). For this same reason when I took it to the Subaru dealer (during the cooler morning), they didn’t note the noise and said all they could hear was the steering rack hitting the stops. I mentioned that I was worried about the CV joints and they said they would drive it around in figure 8’s - again nothing noted. They said they checked the boots and they looked fine. The mechanic that talked to me said something about the pressure in the power steering pump building up when you turn the wheel all the way right or left, possibly making that noise.

a loud thumping (it resonates through the whole car) it isn’t a clicking noise, it is repeated and the rate at which it repeats increases the more the wheel is turned.


  • After the car has been driven about 30 - 40 minutes in 90+ degree heat (the heat may or may not be related)
  • When turning the steering wheel about 180 degrees or more left or right - it only occurs in those ranges of degrees, so I’ve only noted it in parking lot type situations or when doing u-turns. i.e. I haven’t noticed it at higher speeds.
  • It seems to get louder the more the car is driven or the hotter it gets (again not sure which one, possibly they are related)

I’m mainly concerned because I’m doing a trip to Detroit, MI from Texas in a few weeks and I don’t want to get stranded in the middle of no where. If it is indeed the power steering pump and not the CV joints, I’m just concerned about how loud it gets and how it gets more intense the more I drive. Is there something I can replace to make it go away!? Such as the power steering pump?

Nevermind! Just took it back to the mechanic while it was making the noise. They said for sure it is the front passenger side axle.

A 4 year old car, boots intact, only does it when it’s warm…Good luck with that one…

Turned out it was actually a bad center differential.

Also turned out it was expensive to fix.

Do you have 4 matching tires? Mismatched tires (wear, size, even brand) could cause this.

how is newer subaru parts laid out? does car have front transaxle and output shaft sending power to rear center diff? or is there some type of transfer case close to the front transaxle? just wondering about your comment that noise was coming from center diff.