I have a 1992 F-150 302 pickup with 110,000 miles that I bought new and have always taken care of. I have noticed in the last year or so that it was starting to use 1 1/2 qts. of oil between changes. Never smokes at start up or any other time that I could tell. Today I was messing around under the hood and saw a oily spot under the air cleaner box, removed the cover and there was oil in the box and the small filter on the side of the box was trashed ( oil soaked ,falling apart). I remember replacing the small filter once before but thought it was bad from use. I don't take off the air box cover that often because I have a K&N filter.What is going on? cheap fix I hope Ha Ha. Give me your opinions guys. Thanks

 

OK I haven't worked on this model /year Truck but that won't stop me from throwing my $.02 at you.
When was the last time you changed this (breather) filter?
Changed or checked once a year would be good.
When was the last time you cleaned your K&N filter?
You should be at least looking at it once a year too.
Anyway a quart between oil changes for your trucks age isn't that bad. The breather filter does eventually get oil soaked, at least on the cars I used to work on.
Unless somebody else comes on here and says different, and it otherwise runs fine, (you said exhaust looks clean) check, clean, and replace what looks dirty or worn, and go back to enjoying your truck.

 

Check your pcv valve. If that's stuck or clogged the positive crankcase pressure goes out via the breather. As far as I know, breather is for negative crankcase pressure and pcv for positive (PCV=positive crankcase ventilation).
If you change your PCV valve it's a good opportunity to rout it to the vaccum tree and plug the hole in the manifold where it used to go. Helps the number 8 cylinder.

 

The filter you are referring to (crankcase filter) is where the crankcase gets the air that the PCV valve removes. In theory, it should never get oily because the flow should be from the crankcase filter to the valve cover. As an engine ages, wear and tear create more blow-by, and thus more pressure is exerted upon the PCV valve. If the PCV valve were to become dirty and/or clogged, the only place the blow-by would have to go is out the valve cover through that tube and filter, carrying oil with it. I would replace your PCV valve as well as the crankcase filter (the one you are referring to), as well as clean and re-oil your K&N, as suggested above. This should make a difference. How big a difference will depend on how much blow-by you have.

Take care,
-Chris

 

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I bet it is burning oil, 110K. Although 1-2 quarts between oil changes aint bad. Saturn (where I work) says 2 quarts between oil changes is "normal"(they suck). 2 quarts on a new car is not normal, it is acceptable at 110k. I use 3/4 at 99k.

 

I have 65k on my 4.9L, and change the Mobil 1 every 3k, and haven't lost a measurable drop yet. I check the oil every other fill-up, and it never moves.

Hmmm. I guess that's unusual.

Take care,
-Chris

 

Orlando,

What is your oil change interval?

From past experience I have found that 302s are notorious for blowby after 100,000 miles or so. Most of this shows up as milky oil in the crankcase breather filter, the rest is burnt without showing noticable blue smoke out the back. They are also hard to keep rear main seals on them. I had a '79 E-150 with 175,000 miles on it. It used a qt. of oil every 1000 miles with no blue smoke. Some went out the rear seal and some went into the air cleaner, the rest went out the tailpipe.

My current F-150 has 145,000 miles on the 302 and uses 1/2 qt. every 3000 miles. Again, most of it ends up on the transmission (rear main seal) and the crankcase breather filter. Your consumption seems a bit excessive but that depends on your oil change interval.

I would check the following.
1. The PCV valve/crankcase breather assembley (check for vacumn and clean air flow).

2. The rear main seal (check the oil pan/trans junction for leaking oil).

3. Do a compression check for low pressure. This won't tell you the state of your oil rings, but an overall low compression reading will give you an indication of general engine condition.

4. The tailpipe. The best way to check for an engine that is just starting to burn oil is to check at night. In the dark have someone pull up behind you with their headlights on, like in traffic. Rev and let off your engine a couple of times in neutral and see if you notice any smoke in their lights. This will show it a lot sooner that looking in daylight.

Even with the oil consumption you have a lot of miles left in the motor. The blowby doesn't seem to affect the performance that much. Good luck with tracking it down.

DirtBee
'91 F-150 XLT Lariat, 5.0 Auto, Reg Cab 2wd.

 

Just to add to that, you can tell the condition of your rings with a compression test. You just have to do it twice. Once dry (normal compression test), and once wet (squirt some oil from a squirt can (3 squirts) into the spark plug hole just prior to testing each cylinder). The difference in your test results, between the dry test and the wet one, will give a strong indication of the quality of your rings.

Take care,
-Chris

 

I changed the PCV valve , the old one was dirty but otherwise seemed fine but I changed it anyway. DirtBee - I change the oil every 5000 miles as indicated by the owners manual, rear seal was changed miles ago. You are right about it being a milky oil in the breather, thats exactly what it looks like. Sounds like I will have to live with it as it still runs well and I don't want to rebuild. I guess there isn't a cheap fix. Thanks again!

 

If you decide to rebuild consider doing it yourself. My second engine I ever rebuilt was a 5.0HO. All I had was a decent set of hand tools, Haynes manual, and a room and bench in which to spread out stuff on. I rented an engine hoist and stand.
$130 gaskets, rings, and bearings.
$60 rental fees.
$40 timing chain.
I got the eng. ready for pulling, then rented the hoist and stand. Left the car outside and wheeled the eng. inside. Rebuilt it, painted the engine bay and some cool colors on the block and heads, ect. Then re-rented the hoist and put it back in. I was very carefull and took my time. It was done in two weeks in spare time.

Also, consider a local technical school, they'll do it free! You just pay for parts. Usually the instructors make sure everything gets done correctly.

 

On my 87 I pull off the tube between the rocker cover and the airbox and installed a K&N rocker cover filter.It helped alot and the throttle body stayed much cleaner.

 

I have the same problem with my truck (92 f150 302ci)
. The problem has existed since the I purchaced the truck with 42 000 km on it . It now has 247000km on it. Compression has never been an issue. I have replaced the pvc valve several times over the years. It makes no differance. I have blowen out all of the vacuum lines and made sure everything is correctly routed. For the last number of years I have given up trying to repair the problem. It makes no difference to the operation of the vehicle except that you can suck dust in when the filter falls apart. I simply replace the breather filter basically every time I replace the air filter. It is usually in two pieces by then. I have been meaning to replace the breater filter for the last few years with one that doesn't fall apart and forget about it. I know of a few other 92's with the same problem.

If you can find an easy fix please post it. Otherwise I would not lose any sleep over the problem

 

Last time I checked the Ford warranty and policy manual for oil consumption, it stated that a vehicle must get at least 1500 miles per quart of oil.

 

Easy fix: Replace the screen filter below the PCV valve, down in the intake. If that isn't replaced with each new PCV valve, you will have this problem.