Fluctuates....sometimes it's 2 bar. After driving for 30 minutes it could drop to 1 bar or it may just stay at 2 bar. At the next start up it may start out at 1 bar and then drop to .3 bar or just hit the peg and stay there. After a bit more researching, the pressure valve theory seems less likely though, since a friend pointed out that it could be a worn connecting rod bearing. I Then heard the knocking noise as I revved the engine up. I was told that the widening between the bearing reduces oil pressure since you now have the unchanging amount of oil flowing through a larger gap than a smaller one. If this is the case in order to change the rod bearings one of 2 things need to I happen I thing: I can either remove the crankshaft to access both halves of the bearings or I can remove the head to remove the piston to gain access to both halves of the bearings.

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1990 190E 3.0L