PEUGEOT CAR CARE - TIPS AND TRICKS

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Peugeot 505 Diesel Turbo

By Peugeot Pete

XD2S AND XD3T DIESEL ENGINE TURBOCHARGER

Make : GARRETT AIRESEARCH
Type : TA0302
Speed: Up to 100,000 RPM
Intake pressure: 0,6 bar - from 2,000 rpm engine speed
                 at full load, limited by a wastegate
                 which diverts exhaust gasses.
Lubrication    : Under pressure from
                 the engine's lubrication circuit.
Turbine wheel     : Steel
Turbine housing   : Cast iron
Compressor Wheel  : Light alloy
Compressor Housing: Light alloy
Center housing    : Cast iron
Bearings          : Smooth bronze bushings

PRECAUTIONS FOR THE PROPER OPERATION OF THE TURBOCHARGED ENGINE

• Never run the engine with the air filter removed.
• Follow the recommended intervals schedule for oil or filter replacements,
  and use only the recommended lubricants.
• Do not shut the engine off until it's speed has returned to idle, never during acceleration.
• When first starting the engine, wait at least 30 seconds before accelerating to allow the oil pressure to build up.
• After having driven at full load (Turnpike, high speed road) allow the engine to idle down a few minutes before shutting down the engine.

BOOST CONTROL WASTEGATE

The turbocharger and the XD2S,XD3T engines have been matched to provide peak torque at low engine rpm. :18.4 daNm at 2,000 rpm.

To this end, under full load the intake manifold pressure reaches 0,6 bar as soon as the engine runs at 2,000 rpm.

In order to maintain a good operating match between engine and turbocharger under all phases of operation, the turbocharger is equipped with a boost control system called a WASTEGATE.

The wastegate senses turbocharger discharge pressure and will partially divert the exhaust gasses from the turbine. The exhaust gasses no longer transfer energy to the turbine which stabilizes it's speed thereby limiting the rate of boost.

CHECKING BOOST PRESSURE

Checking with no load:

• Use an air pressure gauge that goes to 1,0 bar or more.
• Perform this test with a warm engine.
• Disconnect the air hose to the fuel pump load detector (LDA)  and connect it to the gauge.
• Start engine.
• Allow oil pressure to build up.
• Rev up engine to maximum : MAX rpm without load is 4800 rpm.
• The boost pressure must be 0,4 bar minimum.
• If there is insufficient boost pressure, check:
       - the air intake circuit
       - the engine valve clearances (after 3 ½ hour cool down)
       - the no-load maximum rpm.

Checking boost pressure under load:

• Using a flexible hose of adequate length,
  using a "T" connect gauge in parallel on the LDA and bring gauge into passenger compartment.
• Bring vehicle to a road speed equivalent to 2,000 rpm.

For instance:

Manual Auto
   1^st  12 mph - 18 mph
   2^nd  22 mph - 31 mph
   3^rd  31 mph - 50 mph
   4^th  43 mph
   5^th  50 mph

- If at all possible, perform this test on an incline.
- At 2,000 rpm, under full load, the boost pressure should reach 0,6 bar.

Boost pressure not reached:

Should the boost pressure be insufficient, it is absolutely necessary to check the items below prior to replacing the turbocharger.

• Condition of air filter.
• Check for obstruction in the air intake and exhaust circuits.
• Check for condition of rubber hose between gate valve motor  and compressor housing.

Turbocharger is not repairable at technician level. In the event of a malfunction, it will have to be replaced by a new/rebuilt unit.

PP

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