Picked up a 97 Cougar with the 4.6 and 120K miles, the sweet Anniversary edition, near mint condition cosmetically, but blowing some oil smoke out the exhaust. I am an engine man so no problem, get a low mileage all aluminum version with the better heads, spend about 40 hours grinding, tweeking, blueprinting, and go hotrodding ;-)
Took off the throttle body to give a good cleaning as need this current engine to go another year, lo and behold the oil soaked intake from the PCV about made me puke.
Did some deep research and learned the bigtime engineering mistake Ford made.
The 4.6 uses overhead cams with long a$$ timing chains to each head and cam from the crank. The passenger side head gets completely oil soaked as the timing chain acts as a conveyor belt pumping fresh oil from the crank to the top of the head, the drivers side the chain is going the wrong direction to cause this. The passenger side head has drainback holes leading down to the spinning crankshaft that also get blocked from below do to the direction of the oil windage from the crankshaft, drivers side head not affected.
In the end the passenger head only fills up with oil that has trouble draining back, to the point it covers the valve springs, valve seals, etc.
The higher the RPM, the worse the problem.
BUT - THE THICKER THE OIL THE WORSE THE PROBLEM TOO
Someone deep into the racing curve (I.E. they are hauling *** quicker before most others) posted that the thicker oils in this motor had more aeration problems, I didn't believe it at first, but now I understand with the passenger side problem. An oil lake around a bunch of valve springs at RPM is like whipping up some egg whites.
The 4.6 uses some tight main bearing clearances compared to old school stuff from day one, so can use thinner oil.
The cam bores in the heads are just cut into the aluminum, read need thinner oil so that it gets pumped up to the cam in the head ASAP!
All of the above reasons point to the XW20 oil being speced now by Ford even retroactively. I have no worries switching to it myself now.
The PCV problem is more prevalent to the 4.6 motors that have the PCV on the passenger side, I think some models are driver side mounted.
A fix for the PCV valve is to get an oil/water seperator for an air compressor, costs about $12 from Walmart. Plumb it inline, and watch the oil accumulate. Drain of course once about 1/2" full. Could be used on any engine with PCV I imagine, the 3 cars I tested now all get oil into the seperator.
PS - Could Ford have designed a harder oil filter to install than a 4.6 on these cars? The **** thing has about 0.0000001" of clearance to get around the frickin sway bar. I will dump the oil hot, but that filter ain't coming out unless the motor is ice cold again.
Took off the throttle body to give a good cleaning as need this current engine to go another year, lo and behold the oil soaked intake from the PCV about made me puke.
Did some deep research and learned the bigtime engineering mistake Ford made.
The 4.6 uses overhead cams with long a$$ timing chains to each head and cam from the crank. The passenger side head gets completely oil soaked as the timing chain acts as a conveyor belt pumping fresh oil from the crank to the top of the head, the drivers side the chain is going the wrong direction to cause this. The passenger side head has drainback holes leading down to the spinning crankshaft that also get blocked from below do to the direction of the oil windage from the crankshaft, drivers side head not affected.
In the end the passenger head only fills up with oil that has trouble draining back, to the point it covers the valve springs, valve seals, etc.
The higher the RPM, the worse the problem.
BUT - THE THICKER THE OIL THE WORSE THE PROBLEM TOO
Someone deep into the racing curve (I.E. they are hauling *** quicker before most others) posted that the thicker oils in this motor had more aeration problems, I didn't believe it at first, but now I understand with the passenger side problem. An oil lake around a bunch of valve springs at RPM is like whipping up some egg whites.
The 4.6 uses some tight main bearing clearances compared to old school stuff from day one, so can use thinner oil.
The cam bores in the heads are just cut into the aluminum, read need thinner oil so that it gets pumped up to the cam in the head ASAP!
All of the above reasons point to the XW20 oil being speced now by Ford even retroactively. I have no worries switching to it myself now.
The PCV problem is more prevalent to the 4.6 motors that have the PCV on the passenger side, I think some models are driver side mounted.
A fix for the PCV valve is to get an oil/water seperator for an air compressor, costs about $12 from Walmart. Plumb it inline, and watch the oil accumulate. Drain of course once about 1/2" full. Could be used on any engine with PCV I imagine, the 3 cars I tested now all get oil into the seperator.
PS - Could Ford have designed a harder oil filter to install than a 4.6 on these cars? The **** thing has about 0.0000001" of clearance to get around the frickin sway bar. I will dump the oil hot, but that filter ain't coming out unless the motor is ice cold again.
