93 Explorer, reducing oil usage

93 Explorer, replacing valve & intake gaskets - now with pics!

I am about to embark on a mission to reduce (or eliminate) oil usage.
My ex uses about 1 quart every 250 miles. NO smoke out of the exhaust.

I do frequently smell burning oil out of the engine compartment; room around the valve covers is dirty and somewhat oily (but I cannot see anything actually dripping).

No oil spots on the ground when parked.

I searched around the site and it seems that if there is no smoke, its probably not the rings; so far i am thinking to work on the following:

1. Valve cover gaskers
2. Intake manifold gaskets
3. Valve stem seals

Anything else I should address while I am in there?

Any other thoughts on where the oil might be going?

I am hoping to post pictures as I work on this.

Valve covers and lower intake seem logical....

If the valve stem seals were bad, there'd be smoke out of the exhaust, almost for sure.

Masterd said:

Valve covers and lower intake seem logical....
If the valve stem seals were bad, there'd be smoke out of the exhaust, almost for sure.

Click to expand...

Really? Thats good news, becuase that seems to add a new level of complexity to this. Can I visually tell that they are good once the covers are off?

Gonna clean and maybe even paint the covers while I am at it. It will look cool.

oil leaks

Passenger side valve cover was all oily, the bolts coming out of it, as I was removing them, were soaked, and I could see bubbles when the engine was running.

On another note: can someone please explain to me the significance of the lower intake gasket replacement? How does it contribute to oil leaks? and what is the difference between it and the upper intake?

Something else to look into is the color of your throttle body intake. My 94 was using the same amount of oil as yours, I had what I called "severe" blow-by. The TB was black from all the oil coming through. I'm in process of swapping out that motor for another one with less miles. Look closely at your valves and valve guides. If your that far you might think about new valves and get seats ground. Mine only smoked when I had my foot in it hard, or under heavy loads going up hill!

konstan said:

Passenger side valve cover was all oily, the bolts coming out of it, as I was removing them, were soaked, and I could see bubbles when the engine was running.

On another note: can someone please explain to me the significance of the lower intake gasket replacement? How does it contribute to oil leaks? and what is the difference between it and the upper intake?

Click to expand...

Could you expand on the bubbles bit? Where did you see bubbles? Was the valve cover off?

Alan_V said:

Could you expand on the bubbles bit? Where did you see bubbles? Was the valve cover off?

Click to expand...

Cover was still on, motor running. Around one of the bolts that holds the valve cover on I could clearly see something slowly bubbling. Not a fountain of foam or anything; just looked like a slight air or air and oil leak from under the valve cover...

konstan said:

Cover was still on, motor running. Around one of the bolts that holds the valve cover on I could clearly see something slowly bubbling. Not a fountain of foam or anything; just looked like a slight air or air and oil leak from under the valve cover...

Click to expand...

Pressurized air in the valve cover? Checked your PCV valve? If it's plugged, the pressure in the engine will seek the path of least resistance, often dragging oil with it.

progress report

Took off both valve covers and the upper intake manifold.

Tomorrow going to tackle the lower manifold.

So far it seems that the passenger side valve cover is where the leak was. It was real oily on the outside around the edge.

On the lower intake...

do you plan on re-torquing the bolts or replacing the gasket?

Masterd said:

On the lower intake...
do you plan on re-torquing the bolts or replacing the gasket?

Click to expand...

Planning to take it off and replace the gasket.

can i test valve stem seals

So, while i am in there, is there a definitive way for me to check / test the valve stem seals? It would be a shame to put it back together and realize I need to take it back apart to change them if the gaskets don't fix the problem, and i guess i am obsessing about this a little...

I don't know of a definitive method to check valve stem seals without disassembly. All you can do is look at them between the coils of the spring. But if you're going to take the intake manifold off, look at the backs of the valves. If they're really crusty black, go for the seals. Many engines don't require head removal if you have good valve sealing. With the cylinder at TDC, use a leak down tester and pressurize the cylinder with as much PSI as you can. The pressure will hold the valve closed while you carefully remove the spring. Then you can simple r&r the seal. I don't have any info on whether this will work for the 4.0.

Thank you so much for all the info! Yes, the book does describe the pressurizing of the cylinder as a way to keep the valve open so that the seal can be changed.

Got the lower intake manifold out

Well, i got the intake manifold out. Sure seems dirty inside... here are some pics, what do you guys think?

top of the lower manifold:



bottom:





I am cleaning it with some throttle/injector cleaner and wiping out with rags...

The gasket surfaces look ok...how did the gasket look?

Remember its over 16 years old.

Look down in the intake ports in the head. What's that look like?

Here is the lower intake gasket itself, after I took the manifold off:



It feels kinda "plasticky" and hard, but it was not cracked... One thing I did notice is the manifold did not seem to be on very tight, and once I undid the bolts, it came off with hardly any effort.

Tonight I am going to take pictures, without the old gasket in place, of the valve stems and the intake ports in the heads.

General observation. The valley seems awfully black and grimey. Is that stuff sticky or if you rub it does it come pretty clean? If so, that may be the whole problem.

Alan_V said:

...The valley seems awfully black and grimey. Is that stuff sticky or if you rub it does it come pretty clean?...

Click to expand...

The black grime everywhere is oil (and, I assume, dirt). It is obvious that the oil was leaking from the passenger side valve cover. I think it was also leaking through the lower gasket at least in one spot, because of this: