MY mazda 6 wagon creaks and groans like a couch’s rusty springs, when i start out in the morning, though later it fades somewhat. The noise seems to come from under the car. I don’t know anything about suspension & shock absorbers. Is this dangerous & expensive?
The first thing to check is the suspension bushings.
Dry bushings can produce exactly the symptoms that you describe. If your mechanic lubes all of the bushings in the front and rear suspension, and the noise ceases, then you have found a cheap and easy solution to the problem.
However, if lubing the bushings does not resolve the problem, then it is possible that you have a more serious issue, such as dry/worn-out ball joints. Since bad ball joints are a major safety issue (hint: you could lose a wheel at high speed), you want to find out very quickly whether this is a minor bushing issue or a more serious problem such as bad ball joints.
Most of the time a suspension groan or creak is caused by a sway bar bushing. Age dries the rubber out and cooler weather exacerbates the problem.
Grease can often quieten these down and replacing them if necessary is not a big deal.
Sway bar bushing noise is more of an irritant than a safety issue.
It would also be a good idea to check tie rod ends and ball joints at the same time as a dry joint can do the same thing. As VDCdriver stated, those can be serious safety issues.