Ok so there is a wire running along the back of the oil pan on my 400E and its wire tied to the back of the oil pan? It comes down from one side of the motor and goes up te other side I noticed it goes up under the motor mount bracket on the passanger side? Its in very bad shape, and I need to find ou what it is so I can replace it!

Sounds like the oil level sensor wire, part of LOWER (starter) wiring harness.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

i believe that is one of the knock sensor wires. there is one on each side of the block. they should be shielded with the corrugated black tubing. just replaced my tubing as it went the way of the engine harnesses.

Correct, the knock sensors are under the motor mount arms.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff