cr-rex

iTrader: (114)

what would happen if our motors just ran out of oil? as in, your driving and the oil level in the pan goes to zero or goes lower than the pickup can reach. i think oil starvation is the vocabulary word i'm looking for....

would that blow the motor or what?

adam c

iTrader: (2)

It would depend on how long it ran with no oil. If stopped immediately likely no damage. If not stopped right away, nothing gets lubed, or cooled by oil. I hope you are not going to learn the answer the hard way.

cr-rex

iTrader: (114)

what would happen though? would it just overheat, would it shut off, would it make a sound? would all be well if just re-filled with more oil? how long would a rotary last without any oil?

cptpain

iTrader: (1)

if not shut off immediately.....

pretty much an obliterated engine.....


Im guessing this has happened to you already

cr-rex

iTrader: (114)

eh..... kind of.... well... yes. i was on the togue and in the middle of a hard turn, the car just shut off. not thinking oil, i troubleshot the hell out of the car. it wouldnt start for anything. i could push start it but it would die immediately after taking my foot off the gas. i checked the oil and the dipstick was dry.

i filled it with oil and it started rite up. it sounded like ***. i looked up videos of motors with blown apex seals and tried to compare. the sound that my car is making is different, especially when starting. i could post a video if it would help.

i'm just trying to figure out if the motor is blown and i need to swap it or if maybe something broke or something. someone suggested spark plugs. i havent troubleshot it yet after getting it to start and spark plugs is where i'm going to start...

thewird

iTrader: (8)

It's happened before to me. I saw it on the gauge and ignored it assuming it was a failed sender unit. I was cruising on highway. It drove for 10 minutes with zero noticeable side affects. After 10 minutes, I noticed I was giving it more throttle to maintain speed after which I pulled over and the car stalled. While attempting to call a tow truck I kept trying to start the car, eventually it started up, I drove it for another 5 minutes to the next exit and went to a buddies house. Car still drove but didn't sound to healthy.

Apon pulling the motor and opening it, all the oil control ring seals had melted somewhat (mostly the green ones) and the irons were heat scored. The rotor housings were perfectly fine, the rotors were fine, and the apex seals (ceramic) were fine. I don't remember if the bearings were OK but they had not spun. The e-shaft had extremely minor scuffing which was polished and its the same shaft in my 13b today. Though its coming out this winter after a good 5x,000km since the incident since I'm going 20b.

thewird

thewird

iTrader: (8)

Easy test, do a compression test LOLOLOL.

I think I was getting 40 psi even pulses.

thewird

cr-rex

iTrader: (114)

i would but i dont have any kind of access to any kind of rotary compression tester and i dont think i can make one either? but if my oil seals and all that are toast would it matter if the compression test tests good?

is it possible that there is no damage like cptpain said?

thewird

iTrader: (8)

You can use a standard piston tester and just push the shrader valve when cranking.

If it sounds different, there is some kind of damage unrelated to the oil seals. Regardless you have to open it up.

thewird

Knockers

I would 2nd what thewird said.

I ported the oil passage and left the plug out of the front housing installed the engine. Oil pressure gauge was nada as oil was going right back into the pan, I figured it was a faild sending unit or sumthing. I didn't think anything of it and drove it like that for 600miles. It finally locked up at about 160mph in 5th gear racing a friends car.... Melted the Oil seals to the irons, destroyed all the bearings, the e-shaft was bent and the journals were destroyed... pretty well tosted the motor. The next morining it would turn over and kinda try to start but would not run.

Don't even comp test it, it broke. Pull it and fix it. Don't damaged anything any more than it already is

GoodfellaFD3S

iTrader: (213)

What caused you to run it low on oil?

Also, have you drained the oil pan yet? I'd use a new/clean container to measure the volume of oil that comes out, and also examine it for metal shavings/bearing material.

I've pulled apart a few engines that ran low on oil and the results are never good.

theorie

iTrader: (31)

This:

https://www.rx7club.com/build-thread.../#post11135498

I had an oil line fitting come loose at highway speed and lost most of the oil.

Mahjik

iTrader: (1)

https://www.rx7club.com/3rd-generati...-story-511867/