I have oil smoking out of my oil dip stick and oil filler on my valve cover. Lots of smoke coming out of my PCV valve

ANSWER : Hey there. Worn piston rings create more crankcase fumes (i.e. the smoke you see coming out of breather tubes and orifices). This is called "blow-by". As long as the PCV valve stays clear, and the engine can handle the fume/clean air & fuel mix, then you should be fine.

This is a normal stage of wear as long as tailpipe blue smoke doesn’t become excessive or offensive. The rough running at a stop light may be an early indication of too much blow-by, although those 6 cylinders engines had trouble with rough idle/low speed because of the big differences in the distance between the carb and each cylinder (Cyl 1 & 6 distant, cyl 3 & 4 very close). Keep it tuned, and watch for slow degradation in low-speed running. If you notice this problem worsen or would like to have this checked, then have a qualified professional from YourMechanic come to your car’s location to inspect the smoking problem and follow through with repairs.

ANSWER : Hi There,
It sounds like you may need to replace the oil cap o-ring. If you haven’t done this before there are two O-rings to replace; a small green one on the base of the filter cap stem and the large black one that seals the filter cap (which seems to be the one you are having issues with). The large O-ring sits in a small square-shaped groove that is at the base of the oil filter cap. It is very easy to not properly seat the large O-ring because the threads for the oil cap are quite large and will accept the O-ring if you are not careful. I would suggest having a professional from YourMechanic come to your location to take a look at your vehicle.

ANSWER : Hi there:

When the motor is running at operating temperature, and you remove the oil cap, it’s common for a small amount of smoke to come from the engine. This is usually caused by exhaust gases, heat or gasoline vapor that mixes with the air to create a small amount of smoke. However, if a large amount of white smoke is coming from the dipstick and oil cap, it’s likely that you have internal engine damage; especially if the engine is hard to start. You should probably have the Hyundai inspected as soon as possible by a professional mobile mechanic, so they can determine what might be damaged on your car.

ANSWER : Oil additives are not recommended by any vehicle manufacturer for any reason. Additives that purport to resolve oil leaks are useless, a waste of your money, and may result in engine damage. Every vehicle manufacturer strongly recommends against use of these materials. There is only one recommended and approved repair strategy when it comes to oil leaks: fix the leak.

You can only add the manufacturer specified amount of oil to an engine. If you add too much oil, or too little oil, that will cause engine damage. You should check the engine oil dipstick to determine if there is presently too much oil in the engine. If there is too much, the excess will have to be removed to prevent engine damage.

The leak that you are referring to can be repaired if you request an oil leak diagnostic. If you have further questions or concerns as you decide what to do, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you get the best possible results.

ANSWER : Hi there. When this situation occurs, it’s typically due to one of two things. Either the filter was not replaced (which should be done every oil change) or there is an obstruction inside the oil galley’s with sludge. Also, attempting to "drain a little bit of oil" often backfires and can cause oil pressure problems. The best way to resolve this problem is to start from scratch. Remove the oil filter, drain all the oil, install the new filter and fill with the recommended amount of oil (mixed with the oil stabilizer you are using).

ANSWER : If you had excessive blowby from worn rings and all, then you would have excessive smoking and oil consumption through the engine. It almost sounds like your PCV (positive crankcase ventilation) system is not feeding blowby gasses back to the intake so crankcase pressure is building up in the engine.

The Volvo 850 has a breather box located under the intake manifold. Make sure the vacuum lines to the box are not deteriorated or damaged, and if the box has never been replaced, then it might be a good idea to do so. Failure of the crankcase ventilation system can cause gaskets and seals to fail which can be very costly to repair if the system is not corrected immediately. You may want to enlist the help of a mechanic, such as one from YourMechanic, who will be able to give your car a comprehensive inspection and address all the issues that you’ve listed.

ANSWER : You might not have burned that much oil in 30 seconds of running the motor but the oil is not draining back from the upper parts of the motor. The sludge that has built up in the motor has clogged the return drains in the heads and oil gets trapped up in the valve covers. You should look in one of the valve covers to see if the engine is sludge blocking drains in the heads. If it is then you may have to clean out both valve covers and heads of sludge and then run cleaner through engine several times to remove some of the sludge build up. If this does not help then rebuilding of the motor is only option.

ANSWER : The fuel pump will not stay on if you loose oil pressure. This is why it is shutting off. The loss of oil pressure may be from bad crankshaft bearings or camshaft bearings. The engine oil pan should be removed and the oil pump needs to be checked to ensure that you put in the pick up tube seal to the pump and connected the pump to the block. Then remove at least one main bearing cap and inspect the bearings for excessive wear and crankshaft damage. If you need some help with this, consider YourMechanic, as a certified technician can help diagnose the issue with your oil pressure firsthand and help you fix it accordingly.