Hello, I plan to introduce you to an interesting Fehrler picture. I bought a V70 T5 with a vending machine. On purchase there was a problem (known) that the engine always started to cook quickly. Previous owner changed: cooler and WaPu, without success problem I solved: cracks in the balance tank, exchanged everything Tutti! How far this has to do with the oil pressure first I don’t know, for that I have too little experience with Volvos, therefore I wanted to B5234T3 AW50-42 154T KM (Checkbook up to 130 at Volvo) So to the actual problem: The oil pressure drops spontaneously. This happens when it happens, only with warm engine. I have had it up to now only 4 times on approx. 100km. 1. quiet drive (lamp simply on, engine turned off, oil level checked, tightness, everything i.o.) motor to everything, lamp from… 2. car back to the workshop (to the yard, lamp oil pressure flickers and to, I the speed is increased, from the car out, hood up, engine listen… everything is good, in the car the lamp is already off again.. 🙁 ) So now it became too colorful for me. Oil level i.o., runs without murmuring. I changed the oil incl. the filter. I filled in 5w40 of Total. I also replaced the oil pressure switch. 3. I drove about 25km everything ok. The engine had been warm all the time and also turned higher. Then quickly over a truck. I drove on normally and in the next turn the lamp turned on again. This has stopped the next 1000 meters. I switched off the engine and started immediately. Lamp remained on. Engine stopped again, 7 sec. engine waited again on the lamp…. for the next 30km… :-((( I have now replaced the oil tank replaces the sealing rings. 2x on the tub, 1x on the tube, 1x oil pipe, In the oil tank was a lot of oil sludge I cleaned it. Engine with LiquiMolly cleaner running. Oil (now 10w40 Liqui Molly) and filter changed. Everything was fine again! 4. On the way home (10km) the lamp turned on again. But I didn’t care that I went on. The lamp went out again and has not been on since. About 15 KM! I have no idea what it should be. I can’t imagine the oil pump. How can it lose the oil pressure for a short time and then rebuild it again. n?! I’m sure you still have the one or the other idea! LG, Vadim