Volkswagen Repair: 2002 VW TDI problems, coolant temp, vw tdi

Question
I have recently been having problems with my diesel and was wondering if there
are common problems with the TDI that are good to know. After recent work to
fix an ignition problem (it took several trips back to the dealer I might add) the
glow plug light came on and we were told by the dealer it wasnt an issue.
Now when we try to start the car it will not turn over and makes a groaning
sound. Any info about problems with a TDI would be helpful. Thanks so much!

Answer
The glow plug light and the engine light is two separate lights. So the glow plug light came on well the harness goes bad for the glow plugs. The glow plugs go bad the coolant temp sensor goes bad and the brake switch. These are common problems for the TDI ALH code 2002 engine that kicks on the glow plug light. Timing belts break, the Fuel distributor pump gets off time, or goes bad all together. There are so many variables for this problem I would have to get more info. Does it crank but not start or no crank. The Ignition problem what was diagnosed or replaced. Whats the VIN #. Are you using bio diesel?
Well any way good luck and keep in touch.