figure this one out

Please give any feeback, anything is helpful... I have no idea what this problem is. Ok, ever since I bought my car in 2005, there has been this weird vibration problem. It feels like I am driving over one of those grooved/rumble strips on the side of the highway, just not as hard. It also kind of feels like a flat tire, or frozen in place tire. However, its only in the winter/cold weather.. and at the beginning of the drive, once the car warms up it goes away. I live in Virginia now , so I know its not my tires freezing since it doesnt even get that cold here. it usually only occurs at low RPM, 1-3rd gears, and steering (either direction). Like I said, eventually it goes away, after I get to the high way or it gets nice and warm. I originally thought it was something with the ECS, but I have since replaced my suspsension, lowerd it two inches, and it still happens. By the way the car is a 94 SL. Like I said, any ideas will help.
Thanks

At first I would have said wheels are out of balance but as it warms up it goes away huh? Does it do it only when you steer one way or another by any chance or does it do it while going in a straight line as well? If it only does it when your steering it may be bad power steering pump/belt or maybe CV joint. Those would be my only guesses.

I would say water is somewhere it shouldn't be. Most likely in the tires, which freezes, throwing the balance way off causing your vibration, and then melts putting it back in balance.

hmmm. are we talking about cold as in cold morning with frost on the ground, or are you just saying when the engine is cool?

This rumbling/vibration happens when I turn both ways, AS WELL as when I go straight, but the straight part only occurs for a very short period of time. As far as the wheels go... I have changed them in the past also.. and there is no difference. It occured when I had stock everything on the car, and it still happens now with new rims/tires... and like I said new springs (ECS is unplugged now). And for the temperature, Im talking about outside temperature. Never happens in the summer. Only when it gets fairly cold outside.. overnight. Then early in the mornign it will happen. I'm pretty sure It hasn't happened if I first start it up miday or so... only while its still cold out side... thats why I thought it was the tires also. I guess it could be a coincidence, and both tires got water in them some how.. like suggested. Anyways, thanks a lot for your ideas, like I said, im lost on this. Let me know if any more ideas are out there!! thanks!!

What type of rumbling/vibration? Kind of a difficult question to ask you, but does it change with RPM? vehicle speed? (get louder/more violent) Could it be the power steering system making the noise/vibration? Possibly CV axles?

have someone lift it, check your tires and suspension
i'm very curious to know whats going on myself

Do you have z-rated summer tires? This happens to me when the tires have been sitting for a while and the polyester in the tires cool down and get "stiff" so it forms a "flat spot" until the tires warm up.

2old- i DO have z rated summer tires.... you think it could just simply be that?

Probably... Especially if it only does it when it's cold... If it was a suspension problem, more often then not you would feel it all the time or when it's cold.

I actually spent a while trying to figure a similar problem out until I realized that it didn't happen on my winter tires. I would keep an eye out on the ball joint in the lower control arm though. Technically there shouldn't be enough play for you to "feel" tires like that but it's probably not warn enough to be detected via an alignment either.

Actually I have this trouble on my Caddy.

When their is slush or freezing rain or if I drive through mud--whatever, it collects on the inside of the tire rim. I have to run a hose from hot water tank outside and lay on my back and rinse the underside and rim until it is clean and clear.

I just finished running hot and cold water to my garage so at least now, I can just run the hose out of the spindle to the car and hose her down and then wind it back up.

Before I figured this out, I took it in and had it re-balanced under the lifetime warranty for that and the guy told me the balancing was fine and pointed to a pile of crap that came out from inside the tire rims and said there was your problem.

Once fixed, 85 and no shimmy.

BTW, for the first time this winter, I need to do this again as we go a case of freezing rain and I drove a kid home who lived on these mucky roads and got dirt up inside the rims.

Hope these suggestions help.

Again...mud, snow, or ice on the inside of the rims...first place to check.