I recently took my car to my mechanic for a mandatory inspection for registration. The car is a 2000 Hyundai Elantra.
It needed a bit of work to pass and they did the following:
replaced one wheel with spare (the one on the car was running out of tread)
replaced driveshaft seal
replaced driveshaft boot
replaced two brake cylinders
replaced cracked engine mounting
replaced centre and rear exhaust
rear brake shoes replaced
as well as other things like new wiper blades etc
After getting the car back it seemed fine until I went on a faster road 70-80kph (45-50mph) at which time I noticed that after each small bump this could cause the car to bounce quite a bit. To the point at which I would nearly hit my head on the roof of the car.
From my understanding of cars, this seems firstly like a suspension problem, specifically the dampers (struts) failing. I've read about there being issues with Hyundais of around this era where the struts fail when fully extended after being lifted in the shop.
So I took it back for them to look at here is what they've done
Firstly we confirmed the tyre pressure was correct, and we also made sure that the mechanic on duty didn't increase tyre pressure at all during the service
They suspected the spare tyre so they put the original back on and tested, no difference
They then suspected the struts as I did, and although they said it felt fine from pushing on it, they replaced both front first and tested, still no difference
They then tried replacing the rear struts.. still no difference
They replace all wheels... just in case still no difference
They seem to be running out of ideas, and I'm considering taking the car elsewhere, but I'm curious to know what others might think of this scenario.