W210 98 E300TD PO243 Turbo Problem

[rhugg]

I am experiencing the P0243 code with obvious turbo disfunction. Car has 218,000 miles it just went thru the shop for Timing chain (preventive), glow plugs, and the intake manifold was cleaned. When I got it back I got the SES Light and the PO243 code. I cleared it and found that the vacum line from the EGR valve to the pressure sensor was off at the pressure sensor. I fixed that. It went a week or so. Now I am getting the fault every day. I switched the EGR and Boost Pressure Transducers ... same code. The test procedures now tell me to start checking vacum and voltage (N3/7) test connection.

The Turbo is working at time but I can determine no obvious explanation for when it does or doesn't work.

Any words of wisdom?