Oil - Engine Oil Consumption Testing: Overview
83mercedes01TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS
DATE: June, 1983 REF.NO. 18/22
SUBJECT: ENGINE OIL CONSUMPTION TESTING
Oil consumption measurement, with the aid of a dipstick graduated in millimeters and an Oil Consumption Test Sheet, is now also applicable to engines M116.96.
A total of four test sheets (all previous test sheets are obsolete) and one dipstick graduated in mm, are now available and apply to our late model engines (see listing of test sheets and special tools).
A step-by-step testing procedure for the various engines is outlined on the oil consumption test sheets. Since the testing procedures between different engines vary, the outline on the test sheet must be followed for each respective engine.
The oil consumption test and special tools are also shown on the individual engine microfiche under group 00 or 01.
The following points must be observed during testing:
1. To bleed the engine oil circuit, the thermostat in the oil filter (if so equipped) must be open to allow oil to flow through the oil cooler. This is done by increasing the engine speed until the thermostat opens. At this point, a sudden temperature rise can be felt when touching the oil cooler.
2. On gasoline engines with an upright oil filter, the center bolt of the oil filter must be unscrewed and pulled up for approximately one minute (during the five minute waiting period) to allow oil to drain from the filter housing.
3. For the M110 engine with the oil extraction type dipstick tube (having the purple or pink handle dipstick) there are two oil consumption curves shown on the test sheet chart.
Production phase-in of oil pump with small suction strainer
Chassis As of chassis end number
116.020 071030
116.024 067078
123.033 008473
Select the correct test sheet for the engine to be tested using the chassis/ engine designation located on the heading of each sheet.
FIGURE 1 - CHECK VALVE INSTALLED, ENGINE 617.912:
FIGURE 2 - CHECK VALVE INSTALLED ENGINE 110.985 (IF OIL COOLER APPLIES):
Vehicles with large oil cooler (Inlet at bottom, outlet at top - 0.7 liter capacity) must have the check valve installed between oil cooler and upper oil line in order to prevent drainage of oil cooler during oil consumption measurement (Figures 1 & 2).
On vehicles with small oil cooler (Inlet and outlet at bottom - 0.5 liter capacity), the check valve is not required.
FIGURE 3 - CHECK VALVE WITH ELBOW AND CONNECTING LINE:
Due to the tight space in some models, the check valve with elbow and connecting line must be installed (Figure 3).
FIGURE 1 - CHECK VALVE INSTALLED, ENGINE 617.912:
FIGURE 2 - CHECK VALVE INSTALLED ENGINE 110.985 (IF OIL COOLER APPLIES):
The large oil cooler and upper oil line must be bled prior to the oil consumption test by slipping one transparent hose on each of the two bleed fittings on the check valve (Figures 1 & 2). Remove oil filler cap from valve cover and insert both tubes into filler cap hole.
FIGURE 4:
Run engine and open bleed fittings until oil flows bubble-free. The thermostat in the oil filter must be open on engines with thermostatically controlled oil cooler circuit (see also point one on page 1). Then tighten bleed fittings and remove hoses. Drain oil from hoses into engine.
NOTE: Running a diesel engine without the oil filler cap can cause a considerable amount of oil to be blown out of the engine. Using a filler cap with two holes to fit the hoses is therefore recommended (Figure 4).
Special Tools
Tool Name Tool Number
Dipstick with millimeter graduation (red
handle) for engines with extraction-type
dipstick tube 115 589 15 21 00
Check valve with elbow and connecting fine 110 589 00 91 00
Tele-thermometer 116 589 27 21 00
Oil Consumption Test Sheets
Test Sheet
Engine Print Number
116.960/961/962/963 2049
117.985/986
110.984/985 2048
616.912
617.912 2050
617.950/951/952
A sample of each oil consumption test sheet is enclosed with this Service Information.