Porsche DME 7.8 — OBD II Diagnosis Manual / PAGE 468
DME 7.8 DME 7.80 · This is caused by dirt in the valve lifter.
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DME 7.8 DME 7.80
This is caused by dirt in the valve lifter.
When the Check Engine MIL lights up, a chattering valve lifter may
also occur for a certain time. The DME control module registers
(sporadic) misfiring at one or more cylinders. The mixture adapta-
tion values are normal.
Remedy:
1 - Remove lifter bores, check for damage and blow out oil
passages.
2 - Replace all valve lifters.
3 - During the test drive, listen for valve lifter noises.
Camshaft control badly adjusted
The camshaft control has changed. No chattering noises occur. The
DME control module indicates misfiring for the entire cylinder bank
1 or 2. The mixture adaptation values in the idle speed range differ
in bank 1 and bank 2, the mixture adaptation values in the upper
and lower load ranges are generally normal.
Remedy:
1 - Carry out raw emission measurement:
1. Reset mixture adaptation values (disconnect battery)
2. Disconnect oxygen sensors
If the difference between bank 1 and bank 2 is greater than approx.
0.8 %, then
1 - Reset camshaft control.
2 - Road test vehicle. The mixture adaptation values must
be normal.
VarioCam does not switch over completely
The VarioCam does not switch over completely from power to
torque valve timing.
An indication of this problem is misfiring detected by the DME con-
trol module in the range of 1200 - 1500 rpm occurring in an entire
bank.
The mixture adaptation values are normal.
Remedy:
1 - Replace VarioCam.
2 - Road test vehicle.
0-49 page 2 2470 P0306
p0306 Printed in Germany – 4, 2002
This is a source reference. Confirm exact model applicability in the original material.
