High Oil Consumption: High Mileage Or Bad Pistons?

[MKBLexus]

We own a 2005 GS300 w/over 150,000 m. Dealership telling us for a year high oil consumption is due to high mileage and nothing wrong with engine internally. Now all of a sudden they figured out the pistons, valve rings, and bearings need to be replaced @ a cost of $7,000. After months of taking the car in to find out why, they now have done an oil consumption test to figure this out. Should pistons need to be replaced even at this mileage? Would like to know b4 dropping a few thousand bucks.

[1990LS400]

150,000 miles isn't really high mileage for a Toyota/Lexus engine. My LS400 is at 152,000 miles and it's engine doesn't use a drop of oil between changes. .... same for my wife's Camry V6 which is at 127,000 miles ... and the 90 LS400 I sold in 2003 at 183,500 miles which also had no detectable oil use between changes.

What are the symptoms? How much oil is being used? Any oil residue at the tailpipe? Any visible smoking or leaking? What are the cylinder compression figures? PCV valve OK? Do you know the car's history? e.g. ... Owned it since new? Car been raced or abused? Had regular, on-time oil and filter changes throughout its life?

If you really need a new engine, consider getting a salvage one and maybe have a non-dealer shop install it. Paying dealer labor rates for removing/installing an engine can get pretty high with their labor rates at well over $100/hour.

If the engine really is trashed, maybe its time for a new car? These days, engines are considered lifetime components. I'm known of a number of instances where people who have driven cars to 300,000+ miles on the original engine. My first LS400 was recently sold by its 2nd owner at around 295,000 miles and I'm pretty sure that I would have heard if he had had major engine problems.

[MKBLexus]

We've owned the car since new and Kept it serviced with regular oil and filter changes. Low engine oil light comes on at about 2000 miles after oil changes. We are using Amsoil. The car has never been abused but rather well taken care of. That price is not even for a new engine but just for changing those parts. They offered to shave some labor hours off to get the cost down for us. What the heck does THAT mean?Clearly the dealership costs are inflated. If indeed the pistons are worn heavily as they say, we have a very reliable shop that we use for our other car that we are going to call, get their opinion and an estimated cost to do the job instead. It perplexes me that they kept the car for a week only 3 weeks ago only to tell us that there is nothing wrong with the engine and that oil consumption was normal for the mileage....and suddenly 3 weeks later they found a problem of this nature.

The tailpipe does have black !Removed!, but no visible smoke comes out. Don't know those compression numbers either.

[1990LS400]

You need to be checking the oil level frequently and not waiting for the low oil light to come on. The low oil light on most vehicles comes on when there is very little oil is left in the sump - as little as one quart. Exactly how much oil is being used between 5,000 mile oil changes? Quarts? Gallons? Barrels?

I think you need to have a compression test done. I don't know what the design of the compression and oil control rings on your GS is but usually a good compression test is a good sign that the oil control rings are likely OK.

My main advise is to take your time unless this is some kind of emergency. Get other opinions.

[xxstewart]

Take your car to an INDEPENDENT repair shop and ask them to do a compression test on the engine. This consists of pulling one or more spark plugs, connecting a pressure gauge to the cylinder, and cranking the engine. If pistons and/or valves are bad, compression pressure will measure low because of leakage past the rings or valves. This test should take less than 30 minutes and cost you less than $50, and confirm whether or not you need an engine rebuild. If you do need an engine rebuild, find a reputable independent repair shop that specializes in engine rebuilds, and have the work done there.