[Kurt in NJ]

I have some modern Mercedes that have the extended oil change and built up some sludge, they would have a stroke(suck up clumps of sludge)---a treatment of 'blood thinner" (lifter cleaner detergent) was enough to clear the screen without dropping the pan(engine removal) 2- 500 mile oil changes with a double dose of cleaner -- only as a last resort for people too cheap to fix it properly, but it did work, the problem had not reoccured 3-4 years later(one car died in a flood, other tried to move tree)