2003 Windstar losing oil

My 2003 Windstar has about 150,000 miles on it and is using about a quart of oil every 500 miles. I can't see anything coming out the tailpipe and I don't see any drips on the garage floor. I do see what looks like oil on parts of the engine but if this was the source of the oil loss I thought I would see it dripping in the garage. The van runs fine and doesn't make much noise when running other than some minor spark knock. I've already changed the IMRC bushings which didn't seem to make a difference in oil usage or spark knock.

Any ideas would be appreciated.

Thanks.

I can't see anything coming out the tailpipe
It's very rare to see oil out of the pipe anyway. Usually, it's condensate water that we see out of pipe.

I do see what looks like oil on parts of the engine

That's where the oil is leaking. Throught the lower intake manifold. It's very often on these models. And you will never see oil on your garage when it leaks from here, cause oil accumulates at top of engine.

I guess the oil pressure illuminates on your dashboard?
You don't need to repair the leak.

The knock is under high acceleration?

No, the low oil pressure light doesn't illuminate on my dashboard. Do you think I could be burning off that much oil when I drive the van without smelling it? I haven't smelled it so far and I only see damp spots inside the engine. How difficult is it to fix that type of leak?

The spark knock is typically under hard acceleration. I notice it when mostly when I'm going up a hill near my house where I accelerate from a stop to 55 mph while going up the hill.

Thanks for your help.

Ok, so you burn oil, not leaking it from outside.
1qt/500 miles is reasonable. You'll never smell it if you burn it in that small quantity.
It's hard to repair a leak like that. I don't think is worth to repair a leak like that.

For the knock, it could be caused by a vacuum leak, do you have one?
It could be also clogged injectors or carbon deposit in cylinders.
Try to fill with supreme fuel.

I have the EXACT same problems you describe, except the oil comsumption isn't quite as bad as yours. Maybe 1 quart to 1 and 1/2 quarts per 3000 miles. No drips in garage, no smoke from tailpipe. I'd love to get this solved...

I also had a spark knock that I solved by changing my coil pack. I tried cleaning my plugs and changing my wires but the knock wouldn't stop till I did the coil pack. I could really get it knocking under very light acceleration @ about 45MPH. It's all gone now...

It has a way to test the coil pack. Remove the ignition wires 2 by 2, and measures the resistances between the coil connectors (on same row). You should have between 6.5K to 11.5K ohms. Each row is one coil.

Then disconnect the input coil harness, and check resistance (in coil terminals) between the terminal at front of you and the other terminals. You should have between 0.3 and 1ohm more than the short circuit resistance at each 3 wires. The connectors is at right of the coil.

Anything new on this oil consumption problem? I'm still losing oil somewhere but other than that everything seems OK.

Like I told you, 1qt each 3000 miles is nothing. If there's no oil odor on engine when hot, the problem can come from the 3rd piston ring. It doesn't worth to repair it.

Well, it may be worth repairing ... because it may be nothing more than something amiss on the PCV system. Check the valve and all the hoses, ...especially the fresh air supply hose feeding the valve cover on the "rear" (RH) side of the engine. Make sure the main air filter is in good shape. Any leaking grommet or hose can make the PCV suck too much oil out of the crankcase ... which can lead to plugged EGR jets and/or pre-ignition knock.

I'll check the fresh air supply hose tonight. It's interesting you mention knock because the van has a very slight knock on super light acceleration @ 40-45mph. I noticed a TSB on it about changing the timing a little but I figured with the oil comsumption it could be something else. I've done the isolator bolt fix already and valve cover fix with a new PCV valve.

Ok, I pulled the PCV hose off and a little bit of oil came dripping out. I'm assuming this should not be. I thought the new valve cover with the little shield by the PCV hole would stop oil from getting in there. What's the deal?

Oil in the PCV line is normal......PARTICULARLY now, with the colder weather.
I see that you are in Indiana......so, like Wisconsin.....and most of the midwest......it is cold.
Cold weather greatly increases the fluid that will show up in the PCV line.
I have a catch can on my '96......and it fills up much faster in colder weather......much more water, etc in it.

The PCV line pulles oil vapors from the crankcase.......these vapors contain contaminates that would otherwise cause the oil to break down....and / or cause sludge to build up inside the crankcase.
So, removing them is a good thing.
These vapors are drawn into the cylinders to be burned with the air/fuel mixture.
Some oil droplets will form in the line......and create the deposits of oil that you see.
The updated front valve cover for 1999 and newer windstars reduces the amount of oil drops that are drawn into the PCV line.....while STILL removing the vapors that need to be removed.

On my '96, I have some oil run out of the throttle body, and into the big flex hose.
It looks like a lot.....and it makes a big mess, but it really does not amount to much oil.

What would be a good thing to do....as advised......is to inspect the lines that go from the PCV valve to the upper intake manifold.
Check for any cracks......or signs that the flexible parts have been softened to the extent that they collapse when under vaccum.....which will restrict the flow through the PCV system.

Also....as advised....verify that the breather (in the rear valve cover on 1999 and newer) and the lines going from it......to the fresh air flex pipe are intact.
The breather is how clean air flows INTO the crankcase to replace the air that is drawn out the PCV line.
A restriction from a collapsed or pinched line here can cause the crankcase to be at too great of a vaccum......which can cause excessive oil consumption.
Also.....if the breather line is broken....or disconnected,.....it can cause 2 problems......extra air getting into the intake that the PCM does not know about (through the opening in the flex line)....which can cause lean conditions......
It can also permit DIRTY air to get into both the intake and into the crankcase.....which is not good.

Another thing to check is to make sure that the oil filter does not work loose during use.....but don't over tighten it........
Also.....you might use a gasket on the oil drain plug.....

Again.....If you have the updated valve cover.....and a genunine Motorcraft PCV valve that is in good condition, don't worry about some oil in the PCV line.......it is normal.

If you don't want oil, use a RAMJET in ammont of PCV valve.

Thanks for the quick reply! I'll check that breather line tomorrow when it's light outside. This has been going on for some time now and I have no drips/leaks in my garage so I'm sure the filter/plug cap are good.

Lots of people say not to worry about a little oil consumption but I'm picky like that and would like to get to the bottom of the problem if possible.

Take care of little things ... while they are.

Exactly

I just checked the line from the PCV valve to the intake and found the rubber grommet/adapter at the intake manifold had a hole worn in the bottom of it where it goes from large to small. It was on the bottom of the grommet/adapter so you could not see it unless you pulled it off and flexed it a little bit. I've tried to seal it with tape until I can get a new one and it doesn't seem to have solved the miss at idle I have but hopefully it will help with the excessive oil consumption.

I just checked the line from the PCV valve to the intake and found the rubber grommet/adapter at the intake manifold had a hole worn in the bottom of it where it goes from large to small. It was on the bottom of the grommet/adapter so you could not see it unless you pulled it off and flexed it a little bit. I've tried to seal it with tape until I can get a new one and it doesn't seem to have solved the miss at idle I have but hopefully it will help with the excessive oil consumption.

This is normal. Replace this will not solve anything.
To see why it use too much oil, check for excessive vacuum at PCV valve. If it's good, check compression. Check also lower intake manifold gasket. Especially if you also loose coolant.

For the miss at idle, disconnect MAF sensor. If miss stops, it's either a vacuum leak or a MAF sensor problem/dirt.