Suspension bottoming out?

[ettas13]

Recently blew both my tires on the left, replaced them, I'm running 225/40/18. Over every hole in the road I can feel my left read hitting the body like the suspension is bottoming out, I suspect that's the culprit for my rear tire popping on both side walls. Car is sitting same hight on both sides at the back, I doesn't look like the left rear shock has collapsed. Anyone got a idea what the problem might be? I don't think going back to 17s would be a solution because then I'd be on a thicker side profile. I need to find the problem, don't feel like losing another new tire.

 

[Solo Man]

I have had this metallic sound as if the shocks are gone when going through any uneven part of the road and last week replaced the front shocks. it is a 2012 F30 320d with 200k kms on the odo, so was not surprised when i took the old shocks out to find that you could easily push the piston in without much effort and the piston would stay in that position. So they were totally shot! Got new Bilsteins for about R3.35k for the pair from Goldwagen and fitted them. Before replacing the shocks the car was on an even keel, so i do not think that you will notice the worn shocks by looking at the car as it is actually the spring that keeps the car level. My car has exactly the same size tires on at the moment (they are actually one profile too low but car looks quite nice with the wheel/tire combo. Would very much like to fit 225/45/18 profiles as the speedo is 10kms out at 120km/h at the moment. What car do you have and what is the mileage?