DME 7.8 DME 7.80 · ♦Mechanical causes:

DME 7.8 DME 7.80 ♦Mechanical causes: Valve lifter chattering 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 times adjusted The camshaft control times have changed. No chattering noises occur. The DME control module indicates misfiring for the entire cyl- inder 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 - Set the camshaft control times again. 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: 0-47 page 2 2470 P0304 p0304 Printed in Germany – 4, 2002