2003 Jeep Liberty Using Oil


I have a two part question. First off, I drive a 2003 Jeep Liberty sport with the 3.7 v6. I just passed 161000 miles.

Yesterday I checked my oil level and noticed that I was down two quarts. The oil was changed 3000 miles ago. I added oil to get a safe level. I’ve always used conventional oil with changes every 5k. I monitor the fluid levels and colors between services.

(1) I hear and read differing opinions about oil consumption in older cars. Some have said that my oil consumption rate (1500 miles per quart) is nothing to worry about. Others have suggested that I might take steps to reduce it. I’m not interested in spending tons of dough…I’m saving for a down payment. But if there are simple steps that I can take, why not? The PCV valve is 3 years old. Should I have it replaced? Are there any cleaners or additives that I can add to the oil to reduce oil consumption?

(2) When I removed the oil filler cap, I saw a large amount of yellow sludge inside of it. I’ve read that this is indicative of water in the oil. I’m not losing coolant, so I don’t suspect head gasket issues. I drive a very short distance (1 mile) to the gym every morning before my longer commute (15 miles) to work. I wonder if the short trips are causing the sludge buildup. Any thoughts on that?

1500 miles per quart isn’t anything to be worried about. When it gets to 500 miles, then it becomes more of a concern. And you might not be burning it, might be just a leak. Valve covers at that age and miles could certainly be leaking enough for that amount of loss.

The yellow sludge is more of a concern & should be the place to focus. You should probably have a shop take a look at that. Definitely could be a PCV problem. The PCV valve could be working fine but there could be other problems in the PCV system for example. Probably good idea to have a cooling system pressure test too.

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You can test the PCV valve by simply removing it and shaking it. It should rattle. If it doesn’t it’s gumped up. If it’s gumped up or visibly bad, wash it out well with a spray solvent. Carburetor cleaner will work well for this.

You can also check for signs of seepage past the valvecover gasket. This too can be changed… but unfortunately not just cleaned. If you do this, be sure you use the correct torque. Valvecovers are designed to provide just the right amount of compression on a good valvecover gasket. I do not recommend trying to stop seepage by trying to torque them down tighter. You wouldn’t be the first to break off a shoulder bolt and invent new cuss words.

You could also look at the oil pan gasket for seepage. This too can be changed. Again, access a proper procedure to do so. Hopefully your engine won’t require lifting, or a transverse support require removing, to do so. Some do, some don’t.

You can also check for signs of leakage at the front of the engine. Front seals get old and can allow seepage, and they are changeable. Rear seals can too, but they’re tougher to replace.

Beyond these steps, I consider a quart every 1500 miles to be perfectly good on a 161K engine. Manufacturers typically consider a quart every 1000 miles to be acceptable even on a new engine, however I consider that on the high end of the distribution curve. Others will disagree. But I doubt if any of them would actually tear an engine down with that rate at that mileage. I wouldn’t.

On item (2)… my answer is “yes”. I’d recommend flushing your cooling system well with fresh water and refilling it fresh coolant mix and monitoring it. Use only distilled water ($1/gal at the local grocery store) to mix with the coolant. Tap water can contain all sorts of stuff that, while safe to drink, can cause cooling system problems.

Those are my responses. Others will disagree.

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Great suggestions above, I would like to add too, how do you know you’re not loosing coolant, via the overflow reservoir or have you actually opened the radiator cap (when the engine is cold) and checking the level visually?

My bad! I misread the post! The OP wrote

Apologies to all.

Yes, I would consider the short drives to be the cause. Water vapor is a normal byproduct of combustion. It’s the hydrogen in the hydrocarbon (gasoline) bonding to the oxygen in the air creating H2O (water vapor). Some gets blown into the crankcase via normal “blowby” and, if the air in the crankcase isn’t warm enough to carry the water up with the crankcase vapors and out as the engine runs, it collects in the crankcase. It then can get drawn up to the space under the valvecover with the crankcase vapors and the mix can accumulate as yellow sludge under the oil fill cap.

Leave well enough alone. If you can come up with a down payment for a different car in less than ten years you will be just fine.

Condensation in the oil fill tube is a common sight for this engine, it needs no repair and a cooling system flush will have no affect on this.

Major oil leaks rarely go unnoticed, I doubt your oil usage is due to leaks. Seepage for old gaskets only amounts to a few ounces each year, you will be throwing your money out the window resealing this engine.

The OP’s 15 mile daily commute to work should vanquish most of the water vapor in the crankcase.

It’s a good point, but depends on the ambient temperatures where he resides. North of the 45th parallel it’s been a cold winter.

No harm, no foul. We’ve all been there done that :slight_smile:

A thread dedicated to the yellow sludge .


I live at roughly 41 degrees north. A cold winter indeed.

Now that you know roughly how much oil you are using, increase the frequency of your oil checks.It’s not a good idea to let it get down 2 quarts, especially in the winter when it already takes the oil a little longer to get circulating. Check under the cap each time, too, and clean up any sludge. There is no sense letting any of it drip back into the motor.

As noted, ensure the PCV valve and associated hoses and orifices where the hoses connect are in good shape.

You may wish to consider using a high mileage oil. It may help swell any weeping seals. But do not use an oil with a higher viscosity.

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My 2003 Jeep liberty sport has 153,000 miles and is burning oil about a quart every 1200 miles. Is this normal for this age vehicle? Also I had all oil leak sealed about a year ago and we have kept great maintenance on the vehicle. Any suggestions?

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Just check it often and keep it up to full level.

Yes, some manufacturers state that 1 quart per 1,000 miles is normal. Keep checking it and topping it off when needed!

Audi informs owners of NEW Audis that the consumption of 1 qt of oil every 600 miles falls within “normal limits”.

Not that I needed a reason to pass on Audis, but you can add that to the list!

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My 2012 Camry’s owners manual says 1 Quart in 700 miles is acceptable. I drive about 7000 miles in a year and change it yearly. It drops about 1/8" on a dipstick that has almost 2" between the add and full mark.

To be honest, If that’s the biggest problem you have, you have no problem.