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Filter 1 - General
Filter 2 - Fuel
Filter 3 - Air
Filter 4 - Air (wet)
Filter 5 - Oil
Workshop Tester 1
Workshop Tester 2
Workshop Tester 3
Workshop Tester 4
Gauges + Displays
Clean engine compartment
Multimeter
Clamp-on Ammeter
Alternator (Test)
Scanner 1
Scanner 2
Micrometer
Dial Gauge
Caliper Gauge
Oblique angle
Pulling Tools
Gaskets 1
Gaskets 2
Screws
Data for Monitoring
Leakage Test
On Board Diagnosis
ACC-control
Test Analyser
Compression Check 1
Compression Check 2
Loss in Pressure Test
RPM-Measuring
Fiberscope
Stethoscope
Refractometer
Magn field cur. sensor
Temperature measuring
Layer thickness
Microscope
Anemometer
Engine Test Bench
Perf. Measurement 0
Perf. Measurement 1
Perf. Measurement 2
Brake Test Stand 1
Brake Test Stand 2
Axle Alignment 1
Axle Alignment 2
Axle Alignment 3
Axle Alignment 4
Axle Alignment 5
Axle Alignment 6
Shock Absorber Test 1
Shock Absorber Test 2
Fault finding
Searching f. noises
Hoist
Separation
Wheel Balancing
Petrol Injection Signal
Trigger
Alternator Analysis
Voltage Regulation
Lambda Sensor
Mains voltage 1
Mains voltage 2
Measurement
Measurement 2
Measurement 3
Measurement 4
Measurement 5
Measurement 6
Measurement 7
Measurement 8
Measurement 9
Workshop 1
Workshop 2
Workshop 3
Workshop test 1
Workshop test 2
Workshop test 3
Workshop test 4
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Pressure-loss Testing
As far as the workshop is concerned, the pressure-loss test means a little more time and effort than all the other compression tests. But the much more complex removal of the cylinder head is avoided.Perhaps it is not even worthwhile
testing the engine anymore. In any event, the result of the pressure-loss test is clear and unambigious. It enables conclusions to be made concerning the cost of the repair and sometimes raises the question of a new engine or possibly
even, a new car. Whatever the case may be, the result of the test is very important information for the customer.
| The engine should have operating temperature preferably. |
Normally one would never begin with a pressure-loss test. It will be carried out only then, when other compression tests have pointed to irregularities. Compressed air is pumped into the cylinder through the opening for the spark-/glow
plug or the injector nozzle from the connection on the right seen on the above shown tester. This takes for granted, that compressed air is supplied to the right hand connection of the older tester (pictured below).
Before one applies compressed air to the piston of an individual cylinder, the crankshaft must be secured in the ignition-TDC position. If this is not done, the movement of the crankshaft can set the entire vehicle in motion, which could
cause grave injuries. In the case of a petrol engine, one should make absolutely certain that the ignition is switched off, otherwise sparks from the plug-leads could occur, or the resistance is so high, that the ignition coil could be
destroyed. The danger to persons, when working on an active ignition system, is even more important. Give a thought also to the possibility of the fuel vapour igniting.
| Problems possible in the removing of older glow plugs or injectors. |
Today's simpler testers actually only need a manometer. Is there a second, shows that the inflowing pressure of 4 - 10 bar. The pressurized air squeezes pressure reduced through a calibrated drilling and the more important (second)
pressure gauge has a green marked area. Flows so much more away then entering through the drilling, so the indicator drops below this mark and indicates thereby a defect. More important for a possible repair, is an acoustic test to
determine the cause, and thus, also estimate the cost. 10/15
| Knowledge | Defect |
| 1 | Noises in the exhaust | Exhaust valve(s) |
| 2 | Noises in the intake port | Intake valve(s) |
| 3 | Noises in the crankcase vent or from the dipstick | Piston rings, worn out cylinder sleeves, cracks or holes in the piston |
| 4 | Noises from the spark-plug opening of the neighbouring cylinder | Cylinder head gasket |
| 5 | Bubbles in the cooling system | Cylinder head gasket, crack in the cylinder head |
| Repair | Possible costs |
| 1,2 | Valve replacement, possibly also valve-seat -and guide. Grinding unavoidable | Rather moderate |
| 3 | Complete engine-block restoration, pistons, piston rings, cylinders | High |
| 4,5 | Replacement of the head gasket, possible cyl.head surface grinding | Rather moderate |
| Important: The values hardly change with repeated measurements. |
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