Vibration Problems

[normalicy]

Lets start with the symptoms:
-Vibration at speeds over 55mph (but doesn't really intensify much up to 70)
-Vibration when light breaking
-With heavy breaking, things seem to smooth out

Things I've done:
-Replaced front rotors & pads
-Replaced one tire that was warped (helped a bit with the vibration)

The story:
I bought this car on ebay from a seller as slavaged & repaired. However, apparently we have different ideas of what repaired means. There was sever warping in the front rotors when I got it (felt like I was driving on a washboard road when braking). They didn't say, but it appears that the drivers side & front of the car were what was involved in the accident (confident about the drivers side, due to the panels being that the rockers were severely dented). The front drivers wheel may have also been in the accident.

My first inclination was that the rotors were bad, & so I replaced the front rotors & pads. This significantly helped the stopping vibrations, but they still slightly remained. I then took the car to a tire shop to check the tires for balance. They told me that one was bulging, & so I replaced that one. I'm not sure if they checked the others for balance. This is as far as I have gone so far. I stopped replacing things, because I don't just want to throw money away. I do know that the tire that was really unevenly worn was on the front drivers side & it seemed that the front drivers rotor was the bad one as well. I'm afraid that there may be a problem that is accelerating the wear on the rotor/tire. What should be my next step.

I'm not sure if the vibration & pulsating are related, but they sure seem to be. It is hard to tell where the vibration is coming from, so I can't really rule anything out. Could it be a suspension problem or possibly a wheel bearing or even maybe the rear rotors?

[guardian]

Be sure all four tires/rims have received a careful dynamic balancing. This is not expensive. It may not be a final solution, but it is a logical starting point.

I am most familiar with tires/rims being dynamically balanced off the vehicle, then being refitted. However, in your special situation, it might be worthwhile also to have the tires/wheels dynamically balanced in situ. This procedure also takes into account OTHER rotating components.

Given you car's unusual history you need to find the best, the most professional shop you can to perform this work. Chances are a really good shop is going to have better suggestions than I do. They should. You need first class help in this situation.

Good luck!

[normalicy]

Thanks for getting back to me. I knew that I had "special" needs for my car & I appreciate that you are taking me in the right direction. I'll try the dynamic balancing & go from there. Any clue how much to expect?

[Po Pimp]

I would suggest balancing the tires and having the alignment checked. Since you are spending money most places will offer a free suspension, steering and sometimes brake check. Really they are just trying to get more money out of you but this could at least help you figure out what is going on even if you fix the problem yourself to save money. Can not really problem solve something like this unless alignment is correct, balanced tires and all properly inflated.

[rinverso]

just had my 01 cat in to my service techs for the first time. keep in mind i have a 3 year extended warranty.
my main problem was a leaking power steering pump. i also had a vibration between 50-60. and the battery wasn't holding a charge more than a day.
end result was as follows
1 new tires all around. tech showed the abnormal wear on the front inside.
2 new front brakes and rotors.
3 new wheel bearing
4 new idler arm
5 new serpentine belt
6 new battery
7 new power steering pump
8 new revised high pressure pump hose
9 full four wheel alignment balance yada yada
10 degrease engine and add dye to locate any other leaks
11 front brake sensors.
my out of pocket...$1735 after $100 deductable
warranty company expense...$1882
my mechanic who works in palm beach, florida. on rolls. bentley, mercedes ferrari, etc, etc....was surprised how hard it was to locate oem parts and how difficult the car is to service and lack of cadillac support!!!!
they sent him the oem pump which wouldn't match to the connections on the high pressure hose, due to an unposted revision by cadillac....wait another two days for the car.
wow, this is a scary car....stilll love it, due to the extended warranty.
thanks, robert

[normalicy]

Originally Posted by Po Pimp

I would suggest balancing the tires and having the alignment checked. Since you are spending money most places will offer a free suspension, steering and sometimes brake check. Really they are just trying to get more money out of you but this could at least help you figure out what is going on even if you fix the problem yourself to save money. Can not really problem solve something like this unless alignment is correct, balanced tires and all properly inflated.

I know that the tire that was messed up was balanced for sure. As for the alignment, it doesn't pull at all. Does that still mean that it could need a check. I'll probably fix any problem that I can without extensive equipment. I do know that all of the tires are properly inflated though.

Maybe I'll put some new wheel bearings in first, then get an alignment/dynamic balance. If that doesn't work, I'll just go from there. What's really throwing me on this is that the vibration doesn't feel like an out of balance problem (I've had it on other cars before). Especially since it happens on braking & at high speeds.

[newbee]

I'm having the same problem. The steering wheel and shifter vibrate...well...they just plain shake between 45 and about 65-70. Under that and its fine, over that and its fine. I had this problem awhile back and had it alined and balanced countless times. Since then I've got new tires, and new front brakes. The shaking quit for a long time but now it's back. It's very embarassing to drive girls around in a Cadillac that shakes in weird places.