I have a 99 mercury cougar 2.0l it's burning oil threw the intake manifold I've replaced the pcv valve but it continues to draw in oil and blow out thick white smoke out of the exhaust if I clean the intake out the smoke goes away until the intake fill back up with oil just wondering if anyone else has had this problem

Given the PCV Valves function, 99% of them
have to be on a valve cover to keep the oil
out of the vacuum hose going to the intake
drawing out crankcase fumes

See here p147 for a diagram
http://www.turboninjas.com/camry/eg1.pdf

The PCV valve and hose are on the suction (vacuum) side of the throttle, and this is meant to **** oily crankcase vapours into the inlet manifold for burning.
This should be replaced by fresh air from the upstream or atmosphere side of the throttle, the top hose in the diagram.
When the PCV valve and its hose gets blocked, and the engine is a bit worn, Combustion blow by pressure and oil vapour in the crankcase builds up and is not sucked through the PCV valve. Instead it is forced into the intake tract.
So check the PCV valve, hose, and bleed return hose to make sure they are clear OK. If the problem persists, your engine has probably developed worn piston rings, and blow by is now too high to control properly.

you will need to replace the pcv valve on this one

Clogged PCV Valve
The main purpose of the PCV (positive crankcase ventilation) valve is to recirculate blow-by gases back from the crankcase area through the engine to consume unburned hydrocarbons. Blow by is a mixture of air, gasoline and combustion gases forced past the rings on the combustion stroke. The PCV system usually has a tube leading from the crankcase to the carburetor or intake manifold. Vacuum within the engine intake manifold pulls blow by gases out of the crankcase into the combustion chamber along with the regular intake of air and fuel.
Worn Piston Ring Grooves
For piston rings to form a good seal, the sides of the ring grooves must be true and flat - not flared or shouldered - and the rings must have the correct side clearance in the grooves. Normally, automotive ring groove side clearance should not exceed .002-.004. As the pistons move up and down, the rings must seat on the sides of the grooves in very much the same way that valves must seat to prevent leakage. New rings in tapered or irregular grooves will not seal properly and, consequently, oil will pass around behind the rings into the combustion chamber. Worn grooves are usually flared or tapered causing increased side clearances which permit more than the normal amount of oil to pass the rings into the combustion chamber. Excessive side clearances also create a pounding effect by the rings on the sides of the piston grooves. This promotes piston groove wear and, if the condition is not corrected, breakage of rings lands may occur.
Cracked or Broken Ring Lands
Cracked or broken ring lands prevent the rings from seating completely on their sides and cause oil pumping by a process similar to that described in #7. In addition to this, they also lead to serious damage to the cylinders as well as complete destruction of the pistons and rings. Cracked or broken ring lands cannot be corrected by any means other than piston replacement and this should be done as soon as there is the slightest indication of a crack.
Worn Valve Stems and Guides
When wear has taken place on valve stems and valve guides, the vacuum in the intake manifold will draw oil and oil vapor between the intake valve stems and guides, into the intake manifold and then into the cylinder where it will be burned. If this condition is not corrected when new piston rings are installed, an engine is likely to use more oil than it did before because the new piston rings will increase the vacuum in the intake manifold. When gum or deposits on the valve stems are removed - a procedure recommended when overhauling an engine - the seal previously formed will be removed and leakage will be more pronounced. This is particularly true on overhead valve engines where loss of oil may occur on the exhaust valves as well as on the intake valves. High oil consumption caused by too much valve guide clearance can frequently be cured by reaming or nerraling the valve stem. In some cases new valves may also be required. Use of a permanently bonded valve stem seal will give added insurance against oil leakage on complete engine overhauls or on valve jobs. Large Oil Leaks Leaking valve cover gaskets, leaking crankshaft front and rear seals.

The PCV valve does not control the oil situation, it just keeps the pans and valve covers from blowing off during a backfire. Excessive Oil in the breather is a result of excessive crankcase pressures, usually due to a worn engine, specifically rings.
SOME oil is normal, especially if you are loaded heavily and hard on the throttle.
There is a tester that measures crankcase pressures, but usually some other manifestation shows, like excessive oil consumption.

the PCV system draws crankcase fumes into the intake at idle and lower throttle situations. air going into the crankcase is filtered by the small PCV filter, where the oil shows up....

At highter throttle and lower intake manifold pressures, the system reverses, the PCV valve closes, and the fumes exit the crankcase VIA the breather filter. All of this is normal.

It costs tons less to periodically clean or replace the PCV filter.

itr could be or it cold just be little blow by, i would just clean it up and replace the pcv valve

Try new plugs, wires, fuel filter, air filter, pcv valve, and if its still not too
good,, do the 02 sensors..

Have a good day !

You have worn out piston rings. Excessive blow-by gases goes to the valve train compartment where the PCV valve sucks it into the intake manifold.

You need to replace your piston rings. Blow-by gases from the crankcase goes back with carryover oil to the combustion chamber through the PCV valve that's why you are burning oil and producing bluish smoke. Check if there's oil in the intake manifold.

4 cylinder or 6?

v-6

The PCV Monitor consists of a modified PCV system design. The PCV valve is installed into the rocker cover using a quater-turn cam-lock design to prevent accidental disconnection. High retention force molded plastic lines are used from the PCV valve to the intake manifold. The diameter of the lines and the intake manifold entry fitting are increased so that inadvertent disconnection of the lines after a vehicle is serviced will cause either an immediate engine stall or will not allow the engine to be restarted.