Burning 6qt of oil between changes

I spent all day detailing under the hood, undercarriage and inside /out.
Not a drop of oil anywhere. Just very little road grime in oil pan. No oil puddles. No liquid marks anywhere. Nothing. It's sitting in the garage so haven't driven it to determine any leaks/oil consumption.

The rattling sound concerns me. It did go away.
When it rattled, it was loud just like a flywheel on a bicycle, every time letting off gas pedal wether in 1st gear or 5th gear and remember I drive high RPM. The rattle completely gone when I stepped on gas pedal to accelerate.

So I want to know what caused the rattle in the first place? And what kind of damage? I drove it about 500mi before I could take it into the half quart mechanic.

My best guess is the flywheel, bearings need greased and/or replaced? That's what my ears and gut tells me.
My clutch doesn't slip. I don't know why adding oil would make it go away. And again where did the oil go in the first place?
I'd trust my Amsoil mechanic any day over half quart guy. He was at a dealership, maybe trying to work me with the sales team to trading in my truck for a payment. I take care of my Tacoma and believe I can take it to 400k. Already owned one that had 1986 FJ60 385k original block.
Time will tell if it burns oil or need a new flywheel, valve seals, piston rings, drive shaft??? At 227k my Tacoma has never failed me and ran smooth / perfect except this one rattle. Maybe rattlesnake crawled up in there when I was desert camping ☺️
Thanks to all.... Nobody's touching my truck!

 

id say go ahead and replace or grease the flywheel if that's your gut instinct. itll at least give you peace of mind until it happens again (which it may not!)

 

Do you check the oil in those 7500 miles?

I check it every fill up for this very simple reason...

 

What kind of grease? The whole face of the flywheel, or just the toothed edge? What about those with autos that don't have flywheels? Should we lube the flex plate? So many questions.

 

no idea. never touched a flywheel, but if replacing it gives peace of mind, I say go for it.

 

Well, I figured it was either that or you were joking, and I was willing to play your straight man.

My apologies for guessing wrong.

 

haha no worries.

 

There are quite a significant number of things on a truck that can make a rattle sound. VERY common, is the exhaust heat shields. That rattle might not have had ANYTHING to do with the engine.

I'd suggest that you do this;
1) monitor the oil level frequently until you are confident that it isn't consuming oil at an excessively high rate.
2) after a few thousand miles, take a sample of oil and send it in for analysis. The guys at blackstone can tell you if the engine has been severely damaged by checking the properties of the oil.

Now about the loss of oil...
Oil doesn't necessarily disappear by leaking out. If it was doing that, you PROBABLY would notice a pool of oil on the ground. However, oil loss past the rings or through the crankcase vent will be burned through the engine. Normally, vehicles that have been having this kind of problem for a very long time will blow a lot of blue smoke out the tail pipe, HOWEVER, if a problem just formed recently and the catalytic converter is still working, then the oil may be burning fairly efficiently in the exhaust system.

 

Holy crap batman. I have oil evaporation issues and elevated consumption thanks to 195k of hard use but I have always changed my own oil and never have I drained half a quart. I'd keep an eye on it for sure.

Smell your oil and open the oil fill cap and take a good whiff. If you smell gasoline you have injector leakage. Gasoline in the oil equals faster oil evaporation.

 

Compression leak down test would give indication of rings or valves. Valve stem seals would be my best guess.

 

Brain?

 

if it is as you described above I would check the crankshaft end play... a couple of screwdrivers on the crank pulley and pry forward slightly then push back and see how much it moves... shouldn't be very much at all, a few thousandths... if it clunks, you have found the problem.

 

This is an amazing thread.

1/2 qt. oil drained and the thing runs.

Somebody was not watching the oil level on the dipstick.