idling with no oil/ no ignition

[Patamos]

last week while waiting for my wheel bearings to come back from a shop, i started the engine (rebuilt to the last detail, so don't ask) to find vacuum leaks. that night i drained the oil, to put fresh in before i actually drove it. well i stupidly forgot to put some in the next day, and i started my engine to see if my vacuum leaks were fixed around the throttle body, which was the problem. after about 20-30 seconds of idling at around 2000 (it was cold) i came back in my car to check the gauges and discovered that the gauge for oil pressure was very low, instantly realizing there was little if no oil in the engine. My question is how long can an engine or our 4g63t run with no oil and no scuffing on anything important? please no "i think" responses, cause i need a definite gauge to go of off. this is supposed to be a 5 year long projected to drive, so i need good answers.

 

[beating4g63s]

well there is no 100% definite answer to your question, no one here can say a motor will last X amount of time with out oil, what we can say is that since you previously had oil in the motor it still has "some" lubrication in the motor, also unless you changed the oil filter also you still had oil inside the filter capable of lubing the motor very little in this case. The only true test to see if anything was damaged would be to tear apart the motor and inspect everything OR putting oil in the car and cross your fingers. But if someone on here tells you that your motor will last exactly 5 minutes running with 0 oil then there an idiot and lying to you.

 

[DSM nOOb]

like he said there is no definite answer.

A similar thing happened to me, After a complete rebuild my new oil pump was bad somehow even though when i primed it it worked fine. Anyways with the oil I did have in the galleys and the pump not pumping any oil bearing in my bottom end did get ruined after running for only a minute maybe even less than that.

I would definitely at the very least drop your pan pop some bearing caps and see if you can see any sort of damage IMO.

 

[Patamos]

it's funny you mention that. surprisingly, yes the oil filter was left in, because i didn't have a spare at the time. Also it was definitively not run any more than 35 seconds. i know it was around 30 seconds and then i instantly turned it off. thankfully nothing has seized...yet.

 

[GooeyGus]

No one can definitively tell you if there is damage or not.

At minimum, I would drop the oil pan and pull the rod caps off and see if there is any scoring of the bearings.

Edit: I started typing this reply before any replies were posted, looks like they already got it covered

I would guess at less than 30 seconds, you MIGHT be ok, but there is only one way to find out.

Did you have ANY oil pressure? Was the oil light on?

 

[Patamos]

i had about 2 mm of oil pressure on the guage, and the low oil pressure light surprisingly did not come on even after i turned it off....maybe the low oil psu is bad..hmm...
heres one question i have thats not related to this, how much difference would nt cams make compared to turbo cams?

i had about 2 mm of oil pressure on the guage, and the low oil pressure light surprisingly did not come on even after i turned it off....maybe the low oil psu is bad..hmm...
heres one question i have thats not related to this, how much difference would nt cams make compared to turbo cams?

wow, even after it was turned off, what i really meant to say was the low oil pressure light never came on. period.

 

[jrohner]

If your oil pressure light wasn't on (and it works) I wouldn't worry about it.

 

[GooeyGus]

Let the car sit for a few minutes, turn the key to the on position, does the oil light come on? it should come on with key on/engine off.

If not, check the bulb. If the bulb is good, check the connection at the sender unit.

 

[Patamos]

omw the low oil pressure sending unit was never hooked up, and it looks like the oil filter housing fell on the ground, cause its like half broke. well either way ive been running the engine, and nothing bad has happened yet. ill have to do oil changes very often now; even more than ive been doing before, especially since its rebuilt, and not broken in yet