**7AFE Knocking** Help Revive her!, Help with diagnosis and fix Options

[DST94]

I am usually really good about maintaining my Celica, but I decided that checking the damn dipstick was going to take too much time and ended up driving her 2.5 quarts low on a 200 miles round trip. . . 5 times. On the last trip the oil light flickered and I knew that I was going to have to check it out, but i was less than 10 miles from home so I thought I'd make it. Wrong. I heard a slight knocking but the engine was too loud and I couldn't figure where it was coming from, so I pushed the clutch in to drop the RPMs and quite the engine and the engine violently stalled as soon as I pushed the clutch in. I tried to turn her over while I was coasting but she wouldn't budge. I pulled off to the left, and tried to start her, it was like the battery was dead. Lights flickered, all lights on then slowly fade off. Finally she turned over and was knocking terribly. The knocking got worse as RPMs went higher so I shifted @2000RPMs and limped across the freeway got up to 45mph and pushed the clutch in to begin coasting and got another violent stall. I got to a rest stop coasting and only turned her on to show my dad and the tow truck driver the horrible noise. Haven't turned her on since and have looked up common problems. Spun bearing, messed up rod, messed up crank. I need some help with diagnosis and how to go about repairing this. Ill post pictures and remove whatever necessary. I have until Sunday to fix her, I can fix her, but I've never delved this deep into the engine and need some help. You guys haven't let me down yet, lets not start when I need it most. Thanks guys.

P.S.
If we could refrain from commenting on the low oil. . . I'm not proud of my mistake but I know what I did wrong. . . I could go without the reminders.

This post has been edited by DST94: Nov 23, 2011 - 12:55 PM

[garin]

if you do tear down and rebuild make sure that you get specs for everything and check them out as you go along with the build. plastic gauge will be a nice tool to have for bearing clearances. you may end up finding that you have to put a lot of time and money into it, or orderer new parts. how many miles are on the engine?

[DST94]

if you do tear down and rebuild make sure that you get specs for everything and check them out as you go along with the build. plastic gauge will be a nice tool to have for bearing clearances. you may end up finding that you have to put a lot of time and money into it, or orderer new parts. how many miles are on the engine?

Shes sitting at about 240-240k miles. The cluster isn't exact, that's the reason for the estimate.

So I HAVE to rebuild, this isn't a replace broken part and vroom there she goes?

[stephen_lee]

you lost AT LEAST one bearing. and from the sound of it you kept driving even after the light flickered and even AFTER the engine started knocking. If you stopped when the light came on, you might not have to do a rebuild.

BUT...

The crank will be chewed up. The rod more than likely will be too.
You will have to pull the motor and do a rebuild. Grind the crank, replace the rod that lost the bearing.

You can get away with just replacing the bearings with the engine in the car. but that can last anywhere from 10 miles to the end of the cars life.

[DST94]

you lost AT LEAST one bearing. and from the sound of it you kept driving even after the light flickered and even AFTER the engine started knocking. If you stopped when the light came on, you might not have to do a rebuild.

BUT...

The crank will be chewed up. The rod more than likely will be too.
You will have to pull the motor and do a rebuild. Grind the crank, replace the rod that lost the bearing.

You can get away with just replacing the bearings with the engine in the car. but that can last anywhere from 10 miles to the end of the cars life.

Understood. What do I need to do to figure out what is broken? Remove heads? Expose crank? Drop Oil pan? Where do i start??

[stephen_lee]

The engine is gone already so you can start it and let it idle. pull the injector plugs one at a time and whichever one makes the noise quieter, thats the bad cyl. But that will do more damage to the engine.


Better option is drain the oil, drop the pan. You will be able to wiggle the rod(s) that have lost the bearing.
If it threw a rod, youd know. oil would be everywhere.

But the fact is, you WILL have to pull the motor. no matter what route you go. (unless its the short term cheap just put new bearings in)

I'd just get another used motor. cheaper, faster.

[DST94]

Im going to drop the pan, Ill post in a bit with what i got going on. Thanks for the starting point.

[DST94]

Ok. I dropped the pan and everything, and there are magnetic metal shavings in the oil. I am going to drop the crank case and manually turn it to see if something is going on on the crank itself. After this is accomplished, what is the next step? If the crank is messed up then pull it out and see if its savable? Move onto heads and pistons? What is the next step? Thanks guys.

[stephen_lee]

check the rod journals for scratches. if u can feel them it needs to be ground for sure.

[Smaay]

you are making more work for yourself. pull the engine and tear it down. some people have gotten away with regrinding the crank but i don't think its worth it. several times that bearing just spins again. i suggest a new crank, new rod, while you are in there hone the cylinder walls, replace the pistons rings and all the bearings. i wrote a very detailed guide on how to rebuild the 7A-FE so you can use that for reference.

[Smaay]

http://www.6gc.net/forums/index.php?showtopic=72502 here i did the work for you

[SupraKid]

Buy a new engine Devon.

[bsamps4]

I'm really sorry to hear about what happened. Mistakes happen, even ones that can cost a lot of $. Looks like the advice that you've received from the other members is pretty sound. Honestly from a cost perspective it would be less expensive to find a used 7a at a junk yard and put it in.

This post has been edited by bsamps4: Nov 28, 2011 - 8:18 PM

[stephen_lee]

LOL yeah, i suggested a used engine would be better but still gave the info he wanted.