1998 Expedition Burning Toooo Much Oil...
 

Hi all, I have a problem with my 1998 Expedition. I only change my oil about every 4k - 5k miles or so. I know many do it more often but that's about when I get around to doing it on average I guess.

Anyways, when I go to check the oil it's always considerably lower than the last time I checked it. I mean there have been a couple of occasions where I have had to add 2 - 3 quarts of oil to bring it back up to normal levels.

I use the Valvoline 5-30 or the Motocraft 5-30 PARTIAL SYNTHETIC oils depending on which one I can find.

Anyone have any idea what could be causing this?

Thanx in advance for any help!

-rtb

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Please Note... ATM I do have a couple of issues with my truck although I don't believe they are related to the oil issue. I need to replace a catalytic converter as I have a rattling sound in my muffler and am getting a PO401 code.

I also need to get my rotors replaced in the front as I can feel them when I hit the brakes. Again, I doubt this has anything to do with oil usage but please correct me if I'm wrong :)

if you dont have an oil leak that is leaving a mark,then it could be worn valve stem seals or stuck oil rings. in my exsperiance it is usually the seals

thanx for the reply m8!

hmmm... but wouldn't that leave oil under the car as well? my garage is spot free and i don't see oil collecting anywhere else under the hood.

now, i did go to Advance Auto Parts and they guy there said he thought he smelled oil in my exhaust. there is a bit of smoke coming from the exhaust pipe but i thought it was b/c i needed a catalytic converter.

he explained what he was referring to but all i caught was he thought it was b/c of some kind of pressure problem in the engine where the oil was getting burned up somehow.

i'll have to call up there and see if i can catch him. in the meantime, anyone else have any ideas as to what could be causing this thing to go through soooo much oil.

TIA!

How many miles on this vehicle? could be valve seals/guides head gaskets
rings,. pcv valve.

Like AseTim...I would think rings. Smoke from the exhaust, and the smell of burnt oil could mean that oil is getting past the piston rings and getting burned up.

I agree on the rings and or valves, you could do a compression test to see how far off is was from the specs (usually 125, check manual first). If the compression is low then put a squirt of oil in the cylinder and retest the compression if the compression goes up higher it is the rings if it does not change it is the valves. I know easier said then done.


Lance

The only problem with running a comression test with an oil consumption issue is that it is geared more towards testing the condition of the compression rings and not the oil rings.

Take a good careful look around the engine's cylinder heads for leaks. The way the rear 1/3 of the engine is buried under the cowl, some leaks can be missed.

I hear you on the oil rings it's just A test I have used for many years. just helps narrow the problem. Heck if it's valve seals or rings I would do a whole rebuild anyway. or you would only go so many more miles anf the bearings would go or oil pump ect.

Lance

considering your last post i take it that a compression issue isn't easily remedied?

ok, to answer one question...

miles = 137K approx.

...also, i don't know how to perform either of these tests :(

is there an online "HOW TO" you could point me to?

i did just change the PCV valve a few days ago but haven't checked the oil levels since changing the valve. i doubt that this was the problem as the old one i replaced hadn't gotten to badly mucked up and was still ticking along.

just incase though i'll do some before and after comparisons after my trip up north next weekend.

so...

1- can anyone help me with the a how to on the ring/seal test? linkage?

2- also, where should i look exactly the leaks that are easy to miss as per PaulC's comment?

3- about how many more miles do i have approximately before the engine goes?

Yes if it is the rings then the whole engine will have to be taken apart to remove the pistons, the rings are part of the piston they priamrly keep the oil from going into the cylinder and keep the compression so when the spark plug sparks or ignites it pushes the piston down, the lower the compression the less pressure to push the piston down.

You need a special tool to conduct the compression test, (compression tester) most auto parts stores sell them for about 15.00 to 25.oo$. remove all the spark plugs. then one at a time install the tool into the spark plug hole and turn the engine over. (there is a guage at the end of the tool that will record the pressure. make a note of each cylinder as to their pressure. (all the cylinders should be about the same if one or two is lower than rest then taht is your trouble cylinder). If they all are low then you really have problems. I can't give what the pressue should be untill I get home and check the manual. (Any help on the number)?????

Now for the second test you do the whole thing again only this time you squirt some oil in the spark plug hole then do the test. the oil will go around the rings and if they are bad they will temparaly seal the rings and bring the compression up. it the compression stay the same the rings are good.

Hope this helps ont the v8's it is time consuming but at least you will know the problem. The key to it all is knowing what the compression should be on a new engine. Most vehicles are around 125 to 150 a - 5 is common on older engines.

It helps to have a second person turn over the starter or get another special tool called a remote starter switch. which hooks up to the starter and you push the button from the outside.

lance

thanks a bunch for the quick guide - my nephew put my new spark plugs on so it looks like it's time to give him a call.

ok, so once i figure out what this number should be and start doing the testing no matter if the compression goes up are down during either of the tests then something is wrong right?

if the rings / seals were good then the compression will maintain at or around this number (?) once we figure this out right?

thanx again m8!

i'll lookit up when I get home and get back on the site for you. Give me a hour or two normally don't get off till 1900 hrs opps(0700pm)

Lance

coolio then, i really appreciate it. hopefully, my nephew will know how to do these tests.

when you get back and if you don't mind could you please tell me whether or not there could possibly be something less serious with the truck?

don't get me wrong, i really appreciate the diagnosis it's just that i really don't think i'd keep this thing if something isn't right with the engine and i'd rather not NEED to buy another car.

is there anything less severe that could be wrong with it? couldn't the smoke be a result of the broken catalytic converter? i had that same guy say he thought i also needed to replace the cat b/c you can hear something rattling fairly loudly.

man it would really suck if this thing quit anytime soon :(

thanx just the same though you guys!

Ok I checked my chiltons F150 manual only and no value, pulled out the 1997-2001 chiltons truck service manual - no value, (crap) pulled the last straw and pull the factory service disc for ford. basically what all three manuals say is as long as the lowest compression check value is at least 75% of the highest no mattter what the value the engine is ok. I have the complete procedure on the cpu in a Word document. so since I can't post attachemnts then if you email me at lance_kilgore@Hotmail.com and I will sent it to you off line. It has the values lowest and highest and the complete procedure better than I gave it to you.

Lance