Oil Consumption 2000 JGC V-8

This Jeep has 125,000 miles. Runs good, no problem. I have used Mobil 1 synthetic oil since it was new.

The engine used almost no oil until I got to about 110,000 miles. After that, I started noticing that it was using some oil, which I thought was normal. After now paying closer attention, I see that it now uses one quart every 3,000 miles.

Is this fairly normal oil consumption ?

Thanks for any comments.

--James--

Reply to
James
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I wouldn't think so, my 93 ZJ has over 131k and doesn't burn any oil.

Any leaks? Valve covers, vents, oil in the air filter? Bad or restricted CCV system can suck oil back into the intake. Either way I'd be checking the plugs to see if you have fouling in any cylinder.

Reply to
DougW

What weight oil are you using? Are you sure it isn't leaking?

Carl

Reply to
Carl

James proclaimed:

You will find references that claim that one quart per 3K miles is "normal" for any mileage on the engine. e.g. factories not wanting to deal with loose engines. I'm not one of them.

Is it burning the oil or leaking it?

Typical causes are valve guides, rings, or just ordinary old leaks. Compression pretty much the same in all cylinders?

Reply to
Lon

I have not detected any leaks, or had compression testing. I will pay more attention to the items mentioned, including the possibility of restricted CCV system.

I use 5W-30 weight oil.

My best guess is that it is burning the oil, but I can't be certain.

Thanks to all for the replies.

--James--

Reply to
James

The 5w30 is a little thin for the mileage on that engine. Putting in 10w30 should help.

Carl

Reply to
Carl

Carl , maybe I will try to switch to 10W-30 and see if that makes a difference.

Thanks !!

--james--

Reply to
James

James,

Let us know how muc (if any) improvement there is. I have a few more ideas that will help if just 10-30 doesnt.

Carl

Reply to
Carl

Another thing you can do is "look on the bright side". If you are burning oil, you have upper cylinder lubrication. ;^)

Earle

Reply to
Earle Horton

At normal running temps, 10W-30 and 5W-30 are identical 30 weight oils. The 5W is only that weight when it's cold.

Jerry

Carl wrote:

Reply to
Jerry Bransford

And 5w is so light, it's probably burning when it's cold.

Carl

Reply to
Carl

James proclaimed:

If your engine has gone from burning no oil to suddenly increased oil consumption, something is wrong. It may not be seriously wrong or it might be something that if you don't fix it will cost money. First look for leaks and then if you don't find any, try compression/leakdown test. A good mechanic will often tell you whether it is something that will just cost you a bit of oil consumption or a lot of money.

After you find out what it is, you might want to try a half can of STP in the oil.

Reply to
Lon

STP is great stuff in a really tired engine, but that doesn't really sound like James's problem.

Before adding something like STP I'd try the 10W-30 change and if that didn't do it 10W-40.

But a sudden change would be worrisome, with normal wear the increase should be gradual, I suspect something else is going on, and probably a lot cheaper to fix than a ring job!

(By the way, did you guys know STP used to be a Studebaker product? )

Jeff DeWitt

L> James proclaimed:

Reply to
Jeffrey DeWitt

Reply to
philthy

He has a 2000 V-8 so it should be the 4.7

Reply to
billy ray

Technically STP was a Granatelli product... the guys that scared the bejasus out of the Indy 500 folks until a bearing gave loose.

The problem with all the recommendations to go to 10W anything is that they presume the oil temperature would be staying low orders of magnitude longer than it really does in any engine in temperate climes.

Jeffrey DeWitt proclaimed:

Reply to
Lon

From the STP website:

"In October 1954, three businessmen with a mere $3,000 in start-up capital introduced the first STP® product in St. Joseph, Mo. Scientifically Treated Petroleum, better know as STP, began with one product ? STP® Oil Treatment ? that helped automobile motor oil resist thinning at high temperatures and pressures.

The group, composed of Charles Dwight (Doc) Liggett, Jim Hill and Robert DeHart, began packaging STP® in a backyard garage. They packaged it at night and sold it from the trunks of their cars during their business and pleasure trips. The company?s initial growth and profitability ? attributed to strong word-of-mouth and the brand?s link to auto racing ? enabled STP to introduce its first Gas Treatment in 1960. In 1961, STP was purchased by the Studebaker Packard Corporation. Andy Granatelli was appointed CEO in 1963 and began to increase the brand?s marketing efforts through auto and boat racing. Eventually, STP sponsored its own Indy Car racing team, featuring Mario Andretti, the winner of the 1969 Indianapolis 500."

However if I remember right the three businessmen actually acquired the formula from the German Army and STP started life as a product that helped the German war effort in WWII.

Jeff DeWitt

L>

Reply to
Jeffrey DeWitt

Aside from all the other comments, if it is suddenly using more oil than normal, then ignoring it will just accelerate engine deterioration over time. The oil contamination creates excess carbon deposits that increase wear throughout the engine -- especially the piston rings.

It could be that the valve seals are going bad. I would think that valve seals may be fairly easy on that engine -- once the cam covers are removed. Just getting them off may be a challenge in itself since they're sizeable magnesium castings and there are things in the way.

One possibility would be to determine if there's any blue smoke in certain situations. It may be faint so you may have to ride in a second vehicle trailing your Jeep on a sunny day and watch carefully for puffs of blue smoke.

For example, if there's a puff of blue smoke upon initial acceleration after idling for a minute, I think that would suggest a valve seal issue, since the higher manifold vacuum draws more oil down the valve guides into the cylinder during deceleration and idling. It's not burned much during that idling/deceleration phase, but then when power is applied the oil is suddenly burned, creating the puff of blue smoke.

If you see any blue smoke but it's fairly constant, rather than a puff here and there, that would probably suggest worn rings. This is certainly a possibility since, on the 4.7L, the distance from the top ring groove to the top of the piston is only 1/8 of an inch. That 'dead space' between the piston and cylinder wall above the top ring tends to trap unburned fuel, so reducing that space improves emissions. But then the rings are more susceptible to wear and heat since they're pushed closer to the combustion chamber. The wrist pins also tend to be higher up on the piston nowadays to allow use of longer connecting rods for improved torque, and this means thinner rings which are more crowded together at the top of the piston.

The oil consumption may not be great enough to create noiceable blue smoke, though. And, of course, there are other possibilities. A head gasket problem could allow oil to seep into a coolant passage, so make sure no oil is getting into the coolant...

Reply to
Marcus

Most manufacturers say that 1 quart per 1000 miles can be considered 'normal' so 1 quart in 3000 miles certainly fits in that range.

That being said I would be surprised at that amount of wear in an engine where synthetic had been used since new, or seals damaged under those conditions.

Another possibility could be stuck piston rings, if you were to add one ounce of SeaFoam to each cylinder through the sparkplug hole and let it soak for a hour or so before reinstalling the spark plug would probably remove any deposits causing the rings to stick. Be advised the engine will product a lot of smoke for a few minutes after a SeaFoam treatment.

Sometimes this will break carbon free and cause a misfire, if this happens you may need to clean the plugs (swirl in a bit of SeaFoam) before replacement

If you think the seals may be failing you can switch to one of the 'high mileage' (over 75k) motor oils. They claim to help rejuvenate the seal suppleness.

I think I would stay with 5w-30 oil, especially in the wintertime weather.

Reply to
billy ray

Normal?!!

1 qt in 1000 miles would have a cloud following you down the road and 4000 miles to engine seizure.

I have over 132,000 Miles and have near zero oil loss between changes.

That much oil loss indicates a problem. It may be as simple as a clogged CCV tube or a leaking ring/valve seal.

Checking the plugs will tell you if a cyl is burning oil as the plug will be deeply covered or clogged with soot.

Oil is known to leak from the rear of the I6 valve cover and even the sides.

that, I started noticing that it was using some oil,

Reply to
DougW

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