2003 VW TDI Jetta Surging at Highway Speeds

[4x4dually]

One of my bosses has a Jetta TDI. He had the timing belt replaced and about three weeks after that, it started surging with the cruise set at highway speeds (70-80mph). He says he can put his foot into it and it clears up. And when he takes cruise control off, he can maintain speed with his foot, but the surging is still there, just not as predominant as it is with the cruise set.

Any idears? Is it timing or ????

 

[diesen]

Having the same problem with my 2006 Jetta TDI. Noticed it after removing the broken egr cooler.

 

[4x4dually]

We figured it out. He bought the VCDS diag tool. Neat stuff. We did a run and then looked at the graphs. It told me it was a boost leak. Sure enough, where the square, plastic, intercooler tube is on the passenger side that goes by the A/C compressor was cracked. He taped it for a test and it ran better than it has in a long time. New tube ordered.