Wow...MDK here. I've had many Volvo's since about 1998...has anyone tried a "diesel wash"?.... after next oil change interval , drain 6 quarts and replace filter. Add 6 quarts of Diesel fuel and let it idle for awhile at your discretion. Drain/ re-fill/ replace filter. I know from my exper...

A low Battery or noisy Alternator would trip lots of codes. Get Vida-DiCE setup, clear the DTCs, see what comes back.

As above. Once codes clear, see what's with the oil pressure message. Either the sensor, worn oil pump, or worse failed oil pan o-rings or clogged pick up mesh. With the actual kms, all but a sensor replacement would be a no go for me. If the oil pressure light doesn't return, I'd run it until it di...

It is really hard to tell how bad a sludge issue on a Volvo is b/c the cam cover is the valve cover - so there is no great way to see how the valve train looks. Removing the cam cover is major surgery. Usually from pass side to driver side, valves 1-3 are fairly clean and then they start to get dirt...