Has anybody started the car without the transmission in place? Before I get flamed the reason I ask, is I just put the new rear main seal and the upper oil pan back on the car. I am PARANOID that with my luck I'll have the car all back together and something will leak. I figure I'll start the car, let it run until it is warm and let it run for maybe 15 minutes. Then turn it off and let it sit overnight and check for leaks. Maybe I'll do this a few times just to be sure.

I really dont see anything that would prevent the motor from starting without the transmission. The flywheel would need to be bolted back on for the 2ndary gear and its sensor. To start the car I would use an air impact and spin the crank from the main pully. Or- put the starter in place, but use a stack of washers to simulate the bell housing of the transmission. Thoughts?

 

you could do it but you gotta hook up crank sensor, dunno how you would do that. I dont see how using an impact gun would spin the crank tho??

 

I definitely wouldn't use an impact gun to start the engine. When it finally does turn over, the change in speed is going to rip the gun out of your hand and very violently too.

 

It takes quite a bit of power (around 1-1.5 hp) to turn an engine over fast enough to start it. I don't think there is an impact wrench made that could do it.

 

Does the ECU need the crank position sensor to start the car in the first place?

 

"put the starter in place, but use a stack of washers to simulate the bell housing of the transmission." Would be your best bet but the amount of torque and jaring impact on starter it seem you would need a 1 piece spacer to simulate the bell housing. my $0.02

Even though I would not try it you have it is inventive idea.

 

they make impact guns with over 1000 ft lb of torque...but thats not the point. I dont see how a gun would spin the crank pulley or flywheel, it juss spins the bolt.

 

A thousand ft-lbs at what rpm? Impact guns operate at low cfm, and that limits the power you can get out of them. I suppose you could very well turn a crank with an impact gun, but you might not get enough rpm out of it to start the engine.

If the bolt tightens in the direction the crank normally rotates, then you could rotate the crank through the bolt, unless you twisted the head off, or is that what you meant?

 

you couild break the head off, but that wasnt my point either. Impact gun doesnt spin the crank pulley like it would with a big ratchet. i wasnt quoting a specific 1000 ft lb impact gun so i dont know the specs. i juss know they make them.

 

I am not an expert, but am an experienced mechanic. An impact gun is not what you want to use. U don't want to pound on it, U want to turn it. I have started a 2.0L 4 cylinder engine, mounted on an engine stand, using an electric drill motor with a 1/2" chuck. It worked, but scared the hell out of me when it started. Would have been bad news if the socket didn't dissengage. I would probably never do it again. Also,you should have the flywheel in place and if it is an auto trans, the torque converter. The rotating mass provides the inertia to keep the crankshaft rotating smoothly.

 

OK I got it. I havent cranked over the motor yet cause its about 11 PM and I dont want to wake the neighborhood with the open headered maxima in the garage. See if you can guess what I did:

http://mywebpages.comcast.net/ewong61/max/DSCF0094.JPG
http://mywebpages.comcast.net/ewong61/max/DSCF0093.JPG

 

look like you threw half the tranny on and bolted the started in place...heeh

 

Good thinking, that ought to do it.