: Engine is not cranking - starter is fine



STSCaddyTX
03-04-06, 10:24 PM
Guys, have a question.
My sons 94 STS with N*, will not crank. Funny thing is that he came home and driving to garage, car did not move. Egine was still running. We turn of engine, then try to start, starter was running and selenoid was clicking. I took intake and starter out, and what a supprise. I was able to turn flywheel by the fingers.

Now, question is, what happened. Did bolts from flywheel got snapped? or crank got shattered or broke on the end. I'm working on muscle cars, but never seen enything like this.
Did anyone seen this?I think engine will have to be lowered ,get trany out and look at the flywheel. It is worse the trouble to pull engine out? Car is in a good condition.
What you think? :rant2:

Later Kevin

eldorado1
03-04-06, 10:31 PM
the flywheel has no resistance, it just spins???

I have never heard of that happening before. I'm going to guess you sheared off the flywheel to crank bolts. The flywheel is connected to the crank by about 8 bolts, and to the torque converter by 4. If the flywheel bolts sheared off, the flywheel would still be held in place by the torque converter, but it would spin freely, and obviously no power would get to the tranny. Any metalic scraping noises?

btw, it's entirely possible the crank is now FUBAR'd. Depends on how the bolts failed, whether they can be removed without damage to the crank, etc.

Ranger
03-04-06, 10:37 PM
Hey eldorado1,
I remember someone once talking about the flex plate cracking in a circle. I am not familiar enough with it to commecnt on it. Sounds like you are. Does that make any sense. I guess it is irrelavent as the drivetrain will have to be removed and the engine and trans seperated no matter what the cause.

eldorado1
03-04-06, 10:59 PM
Hey eldorado1,
I remember someone once talking about the flex plate cracking in a circle. I am not familiar enough with it to commecnt on it. Sounds like you are. Does that make any sense. I guess it is irrelavent as the drivetrain will have to be removed and the engine and trans seperated no matter what the cause.

bah, I did it again... right - flex plate. Anything's possible I guess... If you take a look at this pic which looks a lot like the northstar flexplate,
http://i2.tinypic.com/qqa3xd.jpg

The inner bolt holes bolt to the crank, and the outer 4 bolt holes closer to the ring gear bolt to the torque converter. If the inner circle broke off it would do what is being described... I think it would be more likely for one or more bolts to lose their clamping force, and the flexplate to start shifting around, slowly working on the bolts. That's even more likely if the engine has been out at any time, and someone reused the flexplate bolts as-is. I don't remember if they're torque to yield or if they use a threadlock, but I do remember the torque converter bolts did use a threadlock.

STSCaddyTX
03-05-06, 12:07 AM
Yup, ring moves freely, no noice when I crank. I need to try to move flexplate forward and backward, but when I touch it afternoon, did not feel any loose side movement. Just easy spin.

Where exactly it will break? Center plate stay with crank and tq Convertor with outside, or just ring will snap?

:bighead:

fubar569
03-05-06, 02:41 AM
either way you're looking at a tear down...sorry about your luck man!

STSCaddyTX
03-05-06, 11:15 AM
Thanks guys, I'm pushing it on the lift and start to take the engine out.
H**l it will be fun, this is the fist time to get engine out of the caddy.
I can do it in my 69 Mach 1 in the coulple of hours, but these FWD's are pain.
:thumbsup:
Thanks again for reply
Kevin

cart69
03-05-06, 11:41 AM
i did once have a flexplate that cracked around the outside of all the crank bolts and it became loose just like yours is, hopefully its just a flexplate gone bad!!! good luck