Hello Volvo municipality, last Thursday my speed on the way to work began to behave strangely. With gear she commuted in the stand of 900 -1500 Umin. In idle it rose up to 2500 Umin. Later also the engine control started. When reading out came out, too lean mixture. When troubleshooting in the engine compartment I found a torn membrane in the crankcase ventilation. So ordered a new lid and built in. The speed problem is gone but the message with the lean mixture after a while. Can someone give me a hint where to look. The hoses are obviously all OK. MfG