I'm going to look at an 04 that the guys said needs a turbo, I can bring my VagCom to scan it, will that tell me for sure it needs a turbo and not a piston etc. He said it runs fine but smokes. Any ideas? If it needs a turbo is it worth $5000, it has 125,000 miles,in nice shape.

 

Oh wow, your in way over your head.

A vagcom will not tell you if you need a turbo.... or a piston..... or even how you could confuse one with the other because symptoms aren't even remotely similar.

 

Won't a Vag Com show a turbo code, or a misfire cylinder, that would steer me in the right direction , no? It's smoking so a bad turbo smokes and so does a bad piston or rings, I'm just trying to see if someone can help me differentiate between the 2.

 

Unfortunately no a scan will not tell you or give you bad pistons or turbo codes. If you really want the car, pay to have it taken into an independent shop to have a cylinder leak down test and compression test done. If it checks out on those, then its highly likely the turbo seals are bad. You'll be able to know right away if the turbo is whining and louder than normal. What color smoke (black, white, blue?) these are also ways to sort of diagnose what is going on.