I am sorry to hear of you sludging issues with your Passat. The 1.8 liter motor is one of few that tend to blind the pick up screen. I would say that the person looking at your car has offered some good advise. If the flow of oil is already restricted, then the pan should be dropped and cleaned as well as the pick-up screen. This is never a bad thing to do. But even after that was done, there is a whole lot more contamination to be dissolved in this motor. Most of the deposits are likely up in the top end of the motor. And it will take two cleaning and rinse applications to get this motor back to clean and healthy.
Could this motor be cleaned by Auto-Rx, with out dropping the pan and manually cleaning it and the pick up screen? Probably so. It would take more product and running much shorter cleaning and rinse durations than that of the standard application. In your case with oil flow warning lights already being triggered, I would bring the cleaning mileage down to 500 miles, with Auto-Rx installed and then rinse for 1000. Second cleaning bring the cleaning phase up to 1000 miles, followed by a 1500 mile rinse. On a third application, then run a standard application, 3000 mile clean, followed by a 3000 mile rinse. Pay attention to the warning lights.
In many cases folks with these motors change out oil by sucking it up through the dip stick tube. We have found and been told that this method is far inferior when compared to a drain plug in the pan. The siphon method never gets the worst out of the pan and build over time. If this has been your oil change method, I think dropping the pan is the wise thing to do.
I hope this information is useful. Please fire back any further questions you may have.
