Engine burned all my oil in 3 months (~3k miles)

I have a 2006 Tacoma 2.7L manual trans. It has 234,000 miles.

About a month ago I started noticing a metal knocking/pinging in the engine when accelerating slowly on 1st, 2nd and 3rd gear. Then as days passed, the noise started getting louder until today when the “check engine” light finally came on. I decided to check around and noticed the dipstick was bone dry. How or why could that happen? I just did my last oil change in March 2024, I’ve only driven for 3 months around 3k miles and the engine had zero oil. There are no signs of leaks anywhere. I drive it every day and I’ve owned this truck brand new and nothing like that had ever happened. I always do the oil change at ~4k-5k or 6 months.

The “check engine” and noise went away as soon as I topped the engine with 5 quarts of oil.

Am I f*cked? Did I mess up the engine for driving it like that for a month? How could this happen? Anyone with similar experience to mine?

 

If oil isn't all over the bottom of the engine and/or transmission, then it seems unlikely it has leaked.

If it hasn't leaked, it must've burned. (I don't think it's physically possible for several quarts of oil to get blown/mixed into a properly-filled coolant loop, i.e through an oil <--> coolant head gasket leak. A few ounces, sure, but not quarts.)

If that much oil burned in 3K miles -- I wonder if a piston ring and/or oil control ring .. broke? Is that even a thing? Or maybe a valve stem seal failed.

I'm sure you already checked that the oil pan fill bolt was in-place and tight -- right?

If you have access to a compression tester I'd consider that as a first step.

Take clear photos of each of the spark plugs & look for differences. If the problem is in a cylinder and it's just one cylinder, almost certainly that cylinder's spark plug will be badly fouled or at least very different-looking from the rest.

While you have the plugs out, use an inexpensive (<$80) Amazon flex-neck 2-camera scope to inspect the cylinders & valves.

Check the coolant reservoir & radiator and make sure the coolant looks normal.

Your reported metal knocking/pinging sound does not bode well, sounds like a bearing somewhere may be spun or damaged. At least the sound went away when you refilled the oil, but whatever is causing the oil consumption is probably still afoot.

 

All you can do is put oil in, drive it, see what happens.
A first step to see what the issue might be is a compression test.

 

I would have thought you would see a puff of blue smoke when starting a cold engine and if the oil is going that fast I would expect to see some blue smoke upon acceleration.

 

If its ring lands you dont always see them burning oil, the other toyota 4 cylinders will use nearly all their oil in 2 months and the owners will never see a puff of smoke.

Usually if there's tons of blow by you can hear it when the oil fill cap is off while its running.

 

Good point.

 

On this note, check and/or replace the PCV valve, it's a $10 part that usually takes less than 5 minutes to change.

Clogged PCV = crankcase overpressure = increased blow-by.

 

Yes, Gilbert is hopefully correct. Replace the PCV it is not expensive.

Are your piston rings stuck?
They could get stuck from infrequent oil changes, etc.
I do not think that is common in these engines?

Are your Rings worn away?

is a valve(s) stuck?

either way, you should get a compression gauge before you do anything else.

 

If it's burning the oil that fast you can usually smell it when driving behind the vehicle in another with the windows open even if there's no smoke visible.

 

and be ready to clean out clogged cats and o2 sensors...

 

I just can’t imagine burning 5qts and in 3k and there not be some sort of visible sign. We’re talking burning a 1.5qt per 1k. If you’re saying there are zero oil leaks. I can’t imagine no blue smoke, white smoke, burnt oil smell, fouled plugs some sort of sign. I don’t think it could put all 5qts into the coolant and you lot have an issue either. Just crazy.

 

The "knocking/pinging" MIGHT have been the sound of the timing chain slapping as your oil ran low, rather than the CAUSE of the oil running low. Although you likely sustained at least SOME damage from low oil, it could be that you were already burning before you heard the sound. Did you ever happen to check your oil level BEFORE the noise started?

 

Does anyone check the oil when the fill the gas?
I carry an oil rag tucked away under the hood just for this purpose.
That is just basic vehicle maintenance. Takes just a minute and it can be done while waiting for the gas tank to fill.

 

TLDR

OP your motor is done for. It will blow up sooner than later.

 

This is low-effort throw-away remark that does nothing to help OP figure out the source of the issue or how serious it is.

It may blow up, sure, but you have no basis on which to make an authoritative call about it.

My mom drove her 2011 Honda CR-V (4 cylinder) until the "low oil" light came on & the VVT was knocking audibly (due to normal oil burning/consumption.) Filled it back up with oil to the correct level, problem solved, noise went away.

Did a warm-block compression test 1,000 miles later & all cylinders came back perfectly in-spec. It continues to burn a quart of oil every 2K miles but otherwise drives & sounds fine. Sure, it'll foul the cats eventually but that's a separate issue with a longer time-line.

More diagnosis is needed before making any calls on the problems OP outline.

 

He drove around for days on little to no oil, until it started to knock, and continued to drive it for days after that. Prognosis: Negative. That motor is roached. And I only need one paragraph to get my point across.

 

Uh huh. Just like my mom drove her CR-V around for days, low on oil, making rattling sounds, finally figured something out, refilled the oil, and her motor is not roached.

Great value-add there.

 

You do realize that even with the oil not touching the dip stick there is probably still oil in the engine right? If not it would have locked up or thrown a rod etc when driving it for a month.

 

The dipstick being bone dry does not mean the oil was all gone. It just means the level was lower than the dipstick was designed to measure. (not sure if that coincides with where the oil pickup level is though)

Given the age/mileage, it's very likely you are burning. But a more wild theory could be that you have an enemy who got under your truck and drained some oil while you were not around?

 

He says he “topped off with 5 quarts of oil and the noise went away”