Chasing vibration gremlin - subframe questions

Hello,
I've been chasing a slight vibration my car has (2012 Golf R two-door; 87k miles) . Based on my research and feedback from others, it seems like the most likely culprit is stretched subframe bolts. My car came with VWR lowering springs (the only suspension mod on the car) from the previous owner so I'm assuming he didn't change out that subframe mounting hardware when doing that to cause this.

If anyone cares to offer suggestions on the vibration cause in case I may be chasing my tail - the vibration is car speed-dependent and gets more prominent the higher the engine speed. I feel the vibration most in my brake pedals (not lots of action/movement but lots of feel), as well as the arm rest and others have said the rear seats, too. I do also get the typical noises pulling in or out of the driveway.

So again, after researching most of this I decided to purchase the CTS Turbo subframe collar kit which comes with two ARP bolts. My question comes in regard to the rest of the bolts on the subframe. From what I understand all of the subframe bolts are one-time use hardware. Considering that, should I be also buying the rest of the OEM bolts to replace when I install these two ARP bolts along with the collars? And secondly, if anyone has any advice on chasing this gremlin, please fill me in! Thanks in advance!

Doesn't really sound like stretched subframe bolts but nevertheless the kit is great for our cars either way since it secures and stiffens everything up down there. (the common symptom is a "popping" noise/feeling at full turn)

You are correct that they are supposed to be one time use stretch bolts.

What other suspension components have you checked such as end links, or maybe even wheel bearings?

I'd have the tires balanced first to see if that smooths things out. Next up check out the brake discs to make sure they are not warped.

Most likely causes of vibration are wheel balance and worn control arm bushings.

I have to ask - how did you arrive at stretched subframe bolts as the leading candidate?

TimS said:

Most likely causes of vibration are wheel balance and worn control arm bushings.

I have to ask - how did you arrive at stretched subframe bolts as the leading candidate?

Click to expand...

Solely just from reading about the problems in other forums and threads. I found a few threads pertaining to a very similarly located vibration that isn't drivetrain related (vibration continues when in neutral).

I can certainly try balancing them again, although I did have it done a while ago. I kind of dismissed that as generally speaking I keep my wheels excessively clean (I remove them monthly to detail the entire wheel, and wash them while on the car weekly). Although now that I think of it, it's perhaps possible that upon scrubbing the wheels I removed one of the balance weights? I don't know, I feel like I would notice that.

I did consider the bearings also but thought why not install the subframe kit anyway since I eventually will add more aftermarket suspension to the car. Plus, I have already tried a few times lifting the car and attempting to shake the wheel to replicate the noise but I don't have any luck doing so. It seems like the noise can only happen when the car is under it's own load and turning.

Thanks again a ton for all the replies from everyone.

TimS said:

Most likely causes of vibration are wheel balance and worn control arm bushings.

I have to ask - how did you arrive at stretched subframe bolts as the leading candidate?

Click to expand...

Forget to also say that I get the noise that many seem to subscribe when pulling into a driveway or turning in slowly.

These noises never really made me think hub but I did want to ask - how would I be able to diagnose a hub aside from a vibration. Isn’t that typically a noise that sounds like grinding?


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