Quart of oil every 700 miles

[StrayKatJJL]

I have followed a number of post regarding excessive oil consumption but believe I may using more then others with similar posts. This isn't a pcv issue which signifies engine repair as my next step. The vehicle has been very well maintained, and runs great. 180,000 miles now. Can someone give me a ball park cost for doing what needs to be done to eliminate this issue. Is it crazy to just keep putting a quart of oil in every 800 miles ? It doesn't smoke and so there isn't any other problem that I am aware of. Thanks John

 

[sota]

Are you trying to determine the actual problem? or are you just wanting to scatter shot solve it.
if the latter, full rebuild.
are you sure it's not leaking from someplace?

 

[KJowner]

A compression test would be a good start.

 

[ikuo78]

In Japan, cylinder boring costs about $500 for a 6-cylinder engine if you remove the cylinder block and take it with you.
It looks like it will cost about $600 for 6 oversized pistons and piston rings, but it will vary depending on the manufacturer.

Liner replacement and honing will cost about $800 for a 6 cylinder.
In that case you can use a standard piston.

If you leave everything to a shop, it will cost around $3,000.

In the US, it would be about 1.5 to 2 times.
In Japan, a set of Big Mac, drink, and fries costs $5.

 

[lfhoward]

A compression test would be a good start.

Low compression could implicate the piston rings, right? But if compression isn’t low, and it isn’t leaking externally, could it be worn valve guides that let oil seep into the cylinders when the valves open? I know these can be replaced by the DIY-er with an air compressor and the right tools. Martin from the YouTube channel MartinBuilt has a great tutorial on this. He has a 4.7 but the 3.7 uses all the same components. You could replace the valve springs and lifters (aka lash adjusters) while you’re at it, eliminating the tapping noise that old 3.7’s get and reducing the chance of valve train problems down the line.

 

[KJowner]

Low compression could implicate the piston rings, right? But if compression isn’t low, and it isn’t leaking externally, could it be worn valve guides that let oil seep into the cylinders when the valves open? I know these can be replaced by the DIY-er with an air compressor and the right tools. Martin from the YouTube channel MartinBuilt has a great tutorial on this. He has a 4.7 but the 3.7 uses all the same components. You could replace the valve springs and lifters (aka lash adjusters) while you’re at it, eliminating the tapping noise that old 3.7’s get and reducing the chance of valve train problems down the line.

Yes, always worth investigating the cheaper options first, wear depends how the engine has been looked after and how it's been driven. Short journeys wear much more than long ones. A compression test is a good gauge of wear especially if you do it wet and dry.
Assuming the compression is good I'd change the valve stem seals and check guide wear.