QuestionWAS DRIVING MY 2003 VW PASSAT GLS 4-DOOR 1.8T WHEN THE LOW OIL PRESSURE LIGHT CAME ON. WENT TO PULL THE CAR OVER AND BEGAN HEARING A TAPPING NOISE. I CKECKED THE OIL AND THE LEVEL WAS FINE WHAT COULD BE THE PROBLEM, HOW CAN I TROUBLE SHOOT, AND WHAT WOULD IT COST TO REPAIR. THE OIL WAS CHANGED APPROX 5000 MILES AGO IT NOW HAS 36000 MILES ON THE CAR. THANKS FOR YOUR TIME
AnswerHi Rob;
It sounds to me like the oil that's been used in the engine so far is a mineral refined, and/or blend of mineral refined, and synthetic. That's NOT good. Passat 1.8T's work harder than just about any other passenger car engine ever invented, or installed. They all have a tendency to make the mineral refined oils break down, and turn to carbon sludge. The only oils that hold up are pure synthetic oils.
At this point, without seeing the car personally, and doing a couple of tests for oil pressure, and acid content, and fuel content, I can't say with absolute certainty that this is the cause, but it sure sounds like it.
Can you change the oil, and filter?
If so, start by buying several cases of mineral refined oil, you can't start spending big money on synthetic, until after the crankcase is cleaned out. It may not be too late. Buy about 10 Volkswagen oil filters, too. The only filters that seal, and perform up to German standards are the Volkswagen/Audi filters, anyone who says otherwise hasn't seen as many Volkswagens as I have.
Don't buy any quick fix "crankcase cleaners." They are all crap, and will do more harm than good.
To change the filter, and not make a big mess, get a used plastic anti-freeze gallon container, and cut it's top off down to about 3 and a half incheson one narrow side, and then curve up to about 6 and a half inches on the other narrow edge of the gallon container. It will look similar to an out style bathtub from the 1800's, where they were filled with pitchers of hot water in the middle of the room, like in the western movies. The "plastic bathtub" will go under the filter to catch the oil that runs out of it after it is loosened. It catches the oil that's in the oil cooler, too. You have to remove the 3 phillips head screws for the coolant reservoir, and remove the coolant level sensor wire connector from the bottom of it, and then use a "bungy" cord to hold it out of the way. You will almost certainly need an oil filter wrench, too, as the oil filters usually are screwed on tight by dominant male "Silver Back Mountain Gorilla's."(Or at least it seems that way at times.) Then remove the belly pan, and drain the oil from the crankcase. I would suggest removing the little side skirts that hold the ends of the belly pan, and set them aside, and put the belly pan in a safe place for a while, too, because you are going to start to change the oil every 100, to 200 miles. Yep, that's right every 100, to 200 miles. 10 filters, 5 cases of oil...first change now, then in 100 miles another one, that's 2. Then in 150 miles another one, 3. In about 200 miles after that, 4. Check the oil, every time you pull the dipstick for a fuel smell first. If it starts to smell like fuel at 50 miles, change it then, and don't wait until 100 miles. What you will be doing is cleaning out the crankcase, the oil pump pickup screen, the oil galleries, the oil pump, and the camshafts, and lifters, and springs, and valve stems, and upper cylinder head area. When you take off the oil fill cap now, you are able to see a crust, not only on the cap, but also on the plastic camshaft noise suppressors, inside the valve cover. IF, it isn't too late, frequent oil changes with quality oil filters will work together to rid the oil fed areas of your engine with these harmful, abrasive, corrosive components. The reason you hear tapping, or clattering is because the pickup screen is so clogged it can't get enough oil through all of these "coffee grounds"...that is what the broken down oil looks like... to make enough oil pressure to quiet everything down with a nice even film of oil. After you have succeeded in cleaning the inside of the engine with these numerous frequent oil changes, then, and not until the inside of the engine is clean, replace the suction jet pump, and the 3 way, and the 90 degree angle crankcase breather hoses. The suction jet pump directs engine vacuum from the intake manifold to be used by vacuum consumers on the car, like the vacuum assist for the power brakes, and the ventilation system air direction system under the dash for moving air from the front vents to the defroster vents, and so forth. If the suction jet pump isn't replaced, it will not allow the crankcase to "vent" and the interior pressures will eventually blow out all of the seals, and gaskets until the engine seep oil like a broken Wesson bottle, and worse yet one of the first things to normally blow out is the camshaft tensioner seal at the rear of the cylinder head. If it's already covered with oil plan on replacing that too, but not yet. Get the engine cleaned out first. Once this ordeal is complete, and the engine works like it's supposed to again, then switch over to a full synthetic oil product, but don't go 5000, or even 4000 miles between changes. The most you should allow the oil to stay in your Passat from that time forward is about 2500, to 3000 miles...tops! It'll run forever after that. I realize this is a drastic revelation. You thought it might be simple, but it will take some real effort to recover from this situation. I don't know who owned the car before you, or if you owned it since new, but no matter what, oil is the life blood of the engine, and it needed to be changed more often than the factory recommended intervals since new. Furthermore, I don't know but I think pure synthetic oil is required for these engines, and records of changes every 5,000 miles or more are necessary for any type of warranty claim. Just remember ...oil is cheap, and can return the car back to it's once quiet operation. Good luck, Rob. I hope this helps.
