Notes on compression test - AH07.00-P-3004-01WA

ENGINE 111.943/973, 111.946111.946 as of 6/1/98 in MODEL 170

ENGINE 111.974 in MODEL 202 with CODE 491 (US version)

ENGINE 112.922/944, 113.941/960 in MODEL 220

ENGINE 104.943/991 as of 6/1/96, 112.923/943, 113.961, 119.982, 120.983 in MODEL 129

ENGINE 111.944/975, 112.940, 113.943 in MODEL 208

ENGINE 104.995 as of 6/1/96 in MODEL 210 with CODE 491 (US version) with CODE 498 (Japanese version)

ENGINE 112.942, 113.942 in MODEL 163

ENGINE 111.947, 112.911/921/941, 113.940/980, 119.985 in MODEL 210

ENGINE 111.975 as of 8/1/96 in MODEL 202.024

ENGINE 111.975 in MODEL 202.085

ENGINE 111.945 in MODEL 208.435

ENGINE 111.945 as of 6/1/98 in MODEL 208.335

ENGINE 104.941 as of 8/1/96, 111.944 as of 8/1/96, 112.910/920, 113.944 in MODEL 202

ENGINE 104.944/994 as of 6/1/96, 119.980/981, 120.982 in MODEL 140

Fig 1: Identifying Good Image Compression Test

Courtesy of MERCEDES-BENZ USA

Fig 2: Identifying Error Pattern Compression Test

Courtesy of MERCEDES-BENZ USA

The compression can be checked with the HHT or STAR DIAGNOSIS for the initial measurement. A difference in speed of > 8 revolutions for engines 104/112/113, as well as > 5 revolutions for engine 111, may indicate a mechanical fault. Speed differences are different for every engine so that no conclusions can be made with regard to the faulty cylinder.

If the differences in speed are exceeded, a mechanical compression test/cylinder leak test must be performed on all cylinders to locate the fault exactly.