BigJim

Well i got this very nive 83, knowing the engine was carbon locked. The interior is so nice and the exterrior with minor fixes will be very nice as well. Engines locked thou. Got a 50/50 mix atf/mmo in the 4 spark plug holes, i filled them as much as they would take(not much on 3, 1 took alot thou). Its been sitting for 3 days, how long should this mmo/atf treatment take to free this engine up if its gonna free up. A week seeting at most or wat?

Dom

https://www.rx7club.com/forum/showth...hreadid=281207

says overnight....

Have you tried to turn it by hand yet?

85rotarypower

I wouldn't let it sit too long though. Supposedly it can wreck your oil seals. The MMO/ATF are highly corrosive oils (compared to engine oil) that can actually eat away at your oil seals, or so I hear. I don't have any personal experience with that, so I could be wrong about it. Either way, if it was going to work, it would have by now.

BigJim

anyone have any more info, its been a few days and when i put in more oil i still see carbon comminmg out, should i wait longer?

85rotarypower

HAve you turned the engine over yet?

BigJim

Ive attempted to, but its still froze pretty solid, i havnt really torqued on it cause i hear when its ready itl move with only a few lbs of pressure so i havnt really pushed, but ive pushed to where it prolly should have freed up. But i really dont want to part this car out, then have it end up working 5 days after i sell something

85rotarypower

Well, like I said, the ATF/MMO should have worked by now. I have no personal experience with it, but I think the engine is screwed. Just too much for the ATF/MMO to handle.

BigJim

dang, its such a nice car tho lol.

GavinJuice

so pull out the engine and plop in another one or attempt to rebuild it. No sense in junking the car since the engine is shot.

LongDuck

Which way are you rotating the engine?

Remember that carbon locking is often due to carbon flakes from anywhere inside that have fallen into the path of an oncoming apex seal. When this happens, no amount of ATF or MMO is going to dislodge that carbon against the seal.

I would recommend backing the apex seal AWAY from the carbon by turning the engine backwards for about 1 complete revolution of the engine. Then, slowly go forwards again to get the carbon to 'scrape' with the seal and clear up any locking that might have occurred.

Give that a shot, at least, before you strip the car for parts. Good luck,

BigJim

Ive tried turning it backwards and its not moving in any direction. If this one wont free up i think we are gonna get another engine