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Highlander that eats oil

We are a loyal Toyota family that is undetered by the recent gas pedal problem. We have a Highlander (2001) that seems to inhale oil. No puddles underneath and the engine still looks clean. Our mechanic speculated it might need valves or rings. So far it only uses about 1 qt/oil every 2 weeks. How long can we delay a major repair?

Has your mechanic eliminated the really simple things first, such as cleaning/replacing the PCV valve and its related hardware?

Another possibility is that this engine, like many Toyota engines of that era, might be encumbered with sludge build-up. While cleaning out the sludge will be more expensive than the PCV cure, it is still less expensive than some other procedures. However, if the sludging is really bad, then it is very possible that lubrication problems have led to excessive wear with resulting high oil consumption.

Find out exactly what your mechanic has done so far, so that we know what you might need to do in the future.

That engine is the 3.0l and the year is right the sludge problem that Toyota had. Check with your dealer to have that looked at first.

As for how long you can go…Good question…I’ve had old clunkers that lasted 3 years and 100k more miles after they started burning 1/qt week of oil.

So far he just has me checking the oil everyday to get a guage on the consumption. He did mention the PCV, but didn’t say if he checked it. Will call him and ask about these suggestions.

Forget weeks…How many MILES per quart used??

How many miles do you drive per week? 1 quart isn’t bad for 2 weeks if you travel 1000 miles a week. Rocketman

Mileage is funny. Most weeks we only drive it about 300 miles total. Then once or twice a month, we travel to see family and do 300 miles each way. Its on those trips that the oil seems to be consumed most heavily.

see previous posting and reply

Spoke with my mechanic - he checked the PCV, but said it was only telling him if there was pressure and not what the vaccum should be. So, he checked online and found that both the highlander and the avalon had known oil consumption problems. His suggestion is to try K&W engine flush everytime I change the oil and to also use synthetic oil instead. Try this for 3 oil changes at 3K each time and check back with him.

see recent post

What he is really telling you is that these engines have issues with sludging of oil that can lead to high oil consumption. For instance, if the piston rings are gummed up with sludge, that will greatly increase oil consumption. I hope that he knows how to do an engine flush without causing further damage to the engine.

If the engine is badly sludged then I would NOT use an engine flush. What happens sometimes in severely sludged engines when you use a engine flush is LARGE chunks of sludge dislodge themselves from the engine and can get caught in the oil pickup screen…THUS blocking all oil flow which will destroy your engine in about 30 seconds. It’s best to remove the slodge slowly.

Any suggestions on how to clear it without damage?

The only way to do it safely is to take off the valve covers and drop the oil pan in order to manually scoop out the sludge. Once your mechanic does that and also cleans the screen on the oil pickup in the crankcase, then he can use a flush to get sludge out of the oil passages and galleries, which are very tiny passages that he cannot access manually.

Then, he should change your oil very quickly after the flush, followed by a couple of oil changes at 1k mile intervals to clear the crud out of the engine. This all will not be cheap, but it is surely cheaper than replacing piston rings and valve guides. Thereafter, be sure to use an oil change schedule of every 4k miles or 4 months, whichever comes first.

Thank you - will have him check into doing this. I didn’t think of having the sludge come off in great chunks - makes sense that it would do more damage.