white smoke coming from the tail pipe

Possibly a blown head gasket and a shop has to perform tests to determine if the head gasket has failed and here is a article on this http://repairpal.com/testing-for-head-gasket-failure

White smoke it an indication of steam or water being burned off. This is usually cause by a blown head gasket. However there are other possible scenarios but this is the most common. Has the car over heated recently? An easy way to check and see it there is water mix in with the oil, is to take the oil cap off and look at the inner part of the cap. If you see a tan-ish milky like substance this is a good indication that there is water in the oil. You can also check the dipstick for the same substance. http://repairpal.com/testing-for-head-gasket-failure

Coolant Leak