Yes, read the 4 in the title as an A.

When I stop the car, just prior to the point of a full stop, my brakes sort of vibrate, or make a f4rting noise. I don't think this is too unusual, most cars I have owned do this, just a teeny little bit, but my XK8 does it longer and more pronounced/louder than any other car I have had.

You know when you are stopped and barely have your foot on the brake pedal, and the car sort of creeps a few inches, and the brakes are just barely letting the car roll and at this point they kind of vibrate a bit, it is that noise and feel, but much more aggressive, louder, and more feel throughout the car.

I have had this issue since I bought the car, so for about 50k miles, and it never changed even after new rotors and pads. I just thought it was normal for the XK8. Last week, totally unrelated, I replaced my shocks, as the lower shock bushings were worn. I also replaced the inner and outer tie rods and steering rack boots, due to a bent inner tie rod and a torn boot. So after I replaced the shocks, this issue is 98% eliminated, except for a very very slight and innocuous noise barely perceptible - sometimes. It is now what I would consider occasional, and barely perceptable, and normal. I didn't do anything with the brakes, didn't even pull the pads, or calipers, or anything.

All I can think is that somehow the lower shock bushings being worn were allowing the hub to vibrate more than new bushings allow? I know this seems like a reach, but I just can't explain it. And it isn't just me thinking the noise is less, my wife, who is oblivious to anything related to the cars, immediately noticed it and mentioned how smooth and quiet the braking is, in fact she asked if I replaced the brakes.

I would be interested to hear if others have had this excessive vibration, and if anyone can understand why it is gone now. I did see a post in the xk/xkr forum where someone experienced what seems might be the same thing.

 

Interesting.

I've noticed something similar, although I had associated it with the brakes being cold as it seemed not to happen as much after a few stops (or 1 good hard one).

Since I just replaced the front shocks I'll keep an ear out. The lower bushings were in terrible shape on mine for sure.

 

Steve and Charlie, Very interesting, I would have gone with the ABS giving some kind of reaction by the sound of it, but it doesn't relate to new bushings.
Just a side note, they sale bushing for the front lower shock in England for about $40 for the pair on the front. If I was going that way, I would bring back a bag full and sale them for $25 apiece. Wonder why they are $130 here, each?


Wayne

 

Thanks for the thought Wayne, it is without question not the ABS. It is vibration of the rotors and pads, I am sure. But what is apparent, although not obvious why, there is less, to no vibration now.

BTW, while I beleived my shocks were fine, but only the lower bushings were bad, I was wrong, the shocks were weak, and one would not rebound. Only once removed from the car was this noticed. Apparently, shocks do go bad without apparent fluid leaking.

 

The shock theory sounds perfectly plausible.

After all, their job is to dampen movement.

 

Wayne and I replaced both rear shocks in my wife's 2006 XK8 back in October due to the infamous rattling noise that was driving my wife nuts (caused by the internal valve that snaps off and rattles around inside the shock barrel). I thought our efforts would simply make the cabin quiet again with no noticeable perception in ride quality. I was wrong. The rear end rides significantly better now. I don't think there's any question that fresh shocks will dramatically improve all of our cars' ride quality....

 

Jon, Good follow up information. Now, if I could get rid of the 5 pounds I gained eating your wife's sandwiches and cookies we could get to work on my rams. LOL.
15 Degrees this morning and sunshine, where are you?
We were lucky, no stuck bolts. Worked with one member through PM's and both of his shock bolts were frozen in the bushing sleeve he ended up cutting the shock end in half.


Wayne

 

Wayne,

I've been outside this morning blowing the leaf litter off the driveway and stacking firewood. T-shirt and sweatpants as usual. Nice and balmy out there at about 22 degrees. We may get to 45 or so by mid-afternoon. I'll have to change into my shorts....

 

Jon, it's official, there is something wrong with me, been taking pictures of a hawk in the garden. He got a mouse or a bird. Anyway, I'm freezing and it's up to 30.
Surely I need a blood transfusion?


Wayne

 

Wayne,

No blood transfusion needed. Just a big bowl of Jan's simmering homemade chili with a big clump of shredded cheddar cheese on top. That will warm you up for the rest of the day, no question about it....

 

Jon, you have disturbed the English Volcano Gods in Spencer,NC and she has threatened the house of the J's in Raleigh unless appeased with the dish of Chilly and cheese. Now what am I going to do with her. LOL
Have a great day, we are headed to a auction with lots of glassware. Just looking, Yeah, that's going to work.


Wayne


Wayne

 

Wayne,

Tell the Omnipotent British Volcano that when we get together to remove your XK8's rams, I'll be sure to bring a big container of Jan's homemade chili and cheese with me. We can heat it up and scarf it down after we have the rams out and ready for shipping off to be rebuilt. Be sure to have plenty of Salisbury's best Cheerwine on hand because we'll all be extremely thirsty for the rest of the day....

Sure hope you don't come home this evening with a load of glassware and an empty wallet....

Jon