OIL LEAK FROM VALVE COVER

 After replacing the oil seals, oil started coming our from the valve cover ventilation

Excessive oil consumption and leak

The tell-tale sign of a valve cover gasket that has lost its seal is an oil-covered valve cover or a burning oil smell when the engine is running. As oil leaks from a valve cover, it can contact a hot exhaust manifold and burn. A valve cover can leak oil while the engine is running, but not while the engine is at rest.

What causes oil to leak from a crankcase through an air filter

The oil doesn't leak from the air filter rather it would be right if we call it from the crankcase this is intentionally done so as to release excess pressure from the crankcase because of blow by that allows exhaust gases to seep through piston ring gaps it continuously fills up the crankcase with huge amount of exhaust gases and at a high pressure and this must be released somewhere either in the atmosphere or right in the cylinders so that they can be burned so engineers decided to burn them right in the cylinders because venting it outside will be harmful to atmosphere so they are purged into the cylinders. Technically it is known as pcv positive crankcase ventilation where there are two hoses one is connected to the air box (after air filter) and the crankcase to get the crankcase fresh air and it's called breather hose the other hose called pcv is connected to the crankcase and the vacuum of the engine just after throttle body (moving from air filter) in case of a petrol engine.

Oil leak on the hose which came form valve cover to air intake 

The leak starts after changing air filter

PCV (positive crankcase ventilation) valve is blowing by and causing engine oil to go through the PCV tube.  I recommend replacing the PCV valve and clean out the tube. Then every time you have an oil change, I recommend replacing the PCV valve to prevent any more oil consumption and leakage. If you need further assistance with the oil getting on the air filter.

The positive crankcase ventilation (PCV) valve works to evacuate gas from the crankcase of the engine. The PCV valve directs these gases back into the combustion chambers via the intake manifold. This plays a large role in engine efficiency, improving emissions and the overall operation of your vehicle. A bad PCV valve will affect the performance of your vehicle, so there are a few signs to watch out for before the valve completely fails:

Symptoms of a Bad or Failing Positive Crankcase Ventilation (PCV) Valve

A bad PCV valve may have a leak, which will cause excessive oil consumption. In addition, you may also notice oil leaking through the seals and dripping on to the floor of your garage. This is because the pressure in the crankcase may increase when the PCV valve fails, so the oil is pushed out through the seals and gaskets since there's no other way for the pressure to be released. The leak will cause your vehicle to burn oil and leak oil beneath your vehicle. If you notice either of these, consult a professional mechanic to have your PCV valve replaced.

Jeep CJ-7, Water Problems

WATER MIXING WITH OIL ISSUES ON JEEP


Question: I've got an '84 CJ-7, 258 straight six. There is quite a bit of water-oil mixture in the valve cover. I've notice just a tiny bit on the dip stick. But, when I drop the oil there is no water. Also, there is lots of water-oil accumulation in the air cleaner. And I notice the radiator is short on water about every two months. I get the feeling I have either a cracked block or a blown head gasket but the engine is actually running under temp during normal operation.?

A:There's no need to get physical. I don't believe that you're cooling loss is related to the watery-oil problem in the valve cover and air cleaner. It's not uncommon for a vehicle of that age to have small leaks that could account for the loss. The accumulation of water-oil in the air cleaner is a good indicator that the Positive Crankcase Ventilation (PCV) system is not functioning properly. Next, you're going to ask, "Where did the water come from that's in the engine?"

Have you seen condensation on a glass of water? Well, the same thing happens to engines. With temperature change, moisture will condense and collect inside an engine. But, that's only a small part of the picture. The greatest source of water in an engine is the combustion process, the burning of gasoline. How do you get water from gasoline? Gasoline is a hydrocarbon (HC). When gasoline is mixed with oxygen and heat, a thermal-chemical reaction occurs, it burns. Am I scaring you yet?

As the gasoline (HC) and oxygen (O2) burn, they break apart and re-join becoming water (H2O) and carbon dioxide (CO2). Of course there are other chemicals but these two are the main players. The remains of combustion (exhaust) H2O, CO2 and other chemicals are supposed to exit the tail pipe, but that doesn't happen. A portion of the combustion gases leak by the pistons in the engine, into the crankcase.

The job of the PCV system is to pull these gases H2O, CO2, and other chemicals out of the crankcase so as not to contaminate the engine oil. If the PCV system is not operating properly H2O will collect in the valve cover and be forced into the air cleaner assembly. Cold weather will make matters worse.