Ford Escape Automobiles Forum banner
1 - 3 of 3 Posts

·
Premium Member
Joined
·
3,620 Posts
Have you checked that your PCV valve is not gooed up? It is supposed to feed crankcase gases to the intake manifold, and if it is dysfunctional it can feed oil in addition to the gases. Reports of failed PCV valves in the same vintage 3.0 V6 engines causing the engine to eat all the oil between fills of the fuel tank have been seen online.
Would not hurt to check the valve, or replace it as they are a 'wear item'.
One check is to disconnect the filtered air line from the snorkel feeding the engine intake that connects to the cam cover. Engine at idle, you can block the air inlet to the crankcase and after a short while should feel a light vacuum indicating the PCV is functioning and venting(at a slow rate) gases from the crankcase to the intake to be burned. If no vacuum or actual pressure, then the system is not working as desired/designed, and should be checked further.
tom
 

·
Premium Member
Joined
·
3,620 Posts
what brand/weight of oil are you using? Do you do the changes yourself? What are you adding as make-up oil?
The original suggested was 5W-20, I think. Later FoMoCo decided that it would be better(for longevity?) to prescribe 5W-30. I am not positive of the ratings, but they did up the second number.
It may be that if you go to a higher rated oil you may decrease the amount burned. If the engine is a bit tired, or was not maintained very well in the past, I would go higher in both ratings. Mentally, I would go to the 15W-40 that is used in a lot of diesel engines. Start a bit higher, and when hot, is a bit more viscous. Unless you live in a frosty area, the 15W should not cause any problems.
I used to check the 'pressure loss' time on engines with a warning light that indicated a loss of oil pressure by running a hot engine at idle, killing the ignition, and then turning the ignition on as quickly as feasible. The time between engine stop and the light coming on told me how quickly pressure was lost through bearings, etc. The light should come on at about 5psi. If you can imagine(hence the mental) a pressure gauge as you turn the engine off, and ignition ON, the time between the OFF and the light going on is the time the gauge needle would take to fall from normal pressure to 5psi. More or less. The longer, the tighter the bearings, in general.
Exhaust valve guides generally don't need valve stem seals nearly as much as intake valve guides as the exhaust valves are not subject to vacuum trying to pull oil down the guide. The oil changing color and odor are more of an indication of blowby getting into the crankcase. Burned fuel or partially burned will leave the black soot, as will 'stuff' that has accumulated when an engine has not been maintained. The stuff will get entrained in the oil, and carried around, turning the oil black in a short time. Have you looked inside the cam/valve covers to see if there is appreciable deposits? In addition, a too-rich mixture can allow fuel to migrate to the oil, and give it a fuel-like odor.
tom
 

·
Premium Member
Joined
·
3,620 Posts
The amount of VI added to base stock is what determines the second number in the designation. These Viscosity Improvers are 'long chained' constructs that are coiled up when cold, and uncoil when heated. They can become short-chained when run through an engine and encounter rubbing friction, in the past the interface between cam lobes and valve lifter faces. That is where the cam rubs on the lobe and cuts the VI apart over time.
Most new engines have 'roller lifters' where the cam-lifter shear interface is replaced by rolling friction rather than rubbing. The VI bits last a lot longer with roller lifters than in the past.
In the 1980's FoMoCo related to a friend that his oil consumption in a brand new Ranger would not be considered excessive until it used more than a quart in 500 miles. Times change. Drivers have become accustomed to never having to check under the hood. IMO that is a mistaken assumption, and costly if there is a problem. FWIW.
In this case, given there is apparently no visible leakage, the spark plugs show no indication of significant oil fouling, and, I think, no blue cloud following along going down the road. That leaves, IMO, the problem of oil being vaporized in the crankase, and fed to the intake. If the oil used has a low 'word for boiling/vaporization' point, it will turn to vapor, not drops, a gas, as in boiling water gas, and fed to the combustion chamber and burned. There is a possibility the oil selected has a low vaporization temperature, I would read up on any available figures for the oil used, and choose another if the numbers indicated that oil turned to vapor at a low temperature. Couldn't hurt.
tom
 
1 - 3 of 3 Posts
Top