Hello,

New to this board. I have recently bought a '87 300D turbo and did some cosmetic upgrades like 17" Borbet Type C Wheels, European lights etc.
I put the new wheels on, new tires at Tire Rack had everything balanced and now I am experiencing a strong shimmy at exactly 52-55 mph. Its fine up to this speed and if I push through it still vibrates a bit but not much. At the 52-55 mph the vibration is so strong that the whole front of the car seems to hop uncontrollably. Went back to the Tire Rack, verified everything and the wheels/tires are good.
Can somebody help me understand and offer advise ?
I did not notice any vibration with the 15" wheels and factory tires.
Another problem, in the morning ( 65-75 degrees outside) when the engine is cold, after starting the engine has a rough idle for about 30 sec and I get blue smoke. If I rev it up to 2000-2500 a couple of times it gets smoother but the smoke is still there. When it's hot it purrs just fine with just a bit of smoke. What should I look into ?
Thank you.

Marius