My VOLVO (Bj. 99 /2.5 / 144 PS / B5252 S ) has 450 000 km down and normally runs like a Swiss movement. But since recently it mucks as if it had swallowed a machine gun. Also in the 2.3. and 4th gear. …..When I then drove about 1 min and glided constantly evenly, everything runs smoothly again. Until then I stop at some point. I usually drive car gas (ICOM LPG injection), but I immediately tested whether this happens with “normal operation” and see there, it’s like that! So no LPG effect!! I already tried the search function in this forum, but the “hot tip” was not there so far So I ask here again directly, if someone is familiar with my descriptions, or e r could think of what is behind it because of his experiences. a Saxon in Hesse