200T oil pressure problem

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <m0xYOP3-000FjCC@post.cis.smu.edu> randrews@post.cis.smu.edu (Robert Paul Andrews) writes:

> My dad's oil pressure in his 200T has just gone screwy.  The shop ust replaced
> the oil pressure switches figuring that was probably it, but no.  After
> the car is warm, oil pressures drop two low, and the warning light sounds.

Have the shop attach a proper gauge - perhaps the engine's shot.  Otherwise, 
there's a procedure for checking the oil pressure awrning controller that 
should be in the Bentley.  This is the version for the MB engine in the ur-
quattro; this engine is very similar to the later MC engine:
 
>From "Reparaturleitfaden Audi quattro, Ausgabe 10/87, D 000.5147.00.00"

Procedure for checking oil warning light - MB engine
====================================================


Prerequisites:

a) Engine correctly filled with oil.

b) Oil warning light must be on when ignition switched on and engine stopped.

c) Oil temperature must be at least 80c.

d) Rev counter must be functioning normally

Hints:

If the oil warning light does not come on check the oil pressure sender
(G10) and the controller (J114, control number 234).

Only contact "G" on the oil pressure sender is used.

Remove the connector from the oil pressure sender G10.

Connect VAG 1526 [an ohmmeter, I presume] to contact G on G10 via an extension
cable and to chassis ground.

Switch VAG 1526 to the 200 ohm range.

With the engine off, the reading should be 5 to 10 ohms.

With the engine idling, the reading should be 70 to 120 ohms.

With the engine at 3000rpm, the reading should be 170 to 200 ohms.

Attach the ohmmeter between contact WK on G10 and chassis ground.

With the engine idling, the resistance should be zero to 0.5 ohm.

With the engine off, the resistance should be infinite.

If any of the preceding tests fail, replace G10.


Procedure for checking oil warning lamp control unit - MB engine
================================================================

Pull the control unit out of its position (6) on the auxiliary relay carrier.

Connect the VAG 1527 diode check light to contacts 4 and 5 of the socket.

Switch on the ignition.  The diode must light up.  If not, check for a circuit
fault using the circuit diagram.

Connect the diode check light between contacts 5 and 8 of the socket.

Turn the engine over with the starter motor.  The diode check light must blink
during the start procedure, and glow steadily with the motor running.  If not,
check for a circuit fault using the circuit diagram.

Connect the diode check light between contacts 2 and 4 of the socket.

Switch the ignition on.  The diode must light up.  If not, check the oil
pressure sender and/or the circuit for faults.

Pull the connector G off the oil pressure sender G10.  The diode must not light
up.  If it does, check for a short circuit using the wiring diagram.

Connect contact 6 of the socket to chassis ground using a piece of wire.  The
oil warning light must light up.  If not, check for a circuit fault using the
wiring diagram.

If all tests are completed successfully, replace the J114 control unit.



-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club