[rlee]

hi guys im new here and i need some help, ive just replaced the engine in my astra its a 1996 gls 1600 16v ecotec. the problem im having is that when i connected the starter motor and turned the engine for the first time it turned over, then it started to just spin the starter!! so i got another one from the scrapper and this was the same so i got another and this is the same!!!!!!!! the engine codes seem to be the same on the new engine its a x16xel and on the old one it looks the same its a bit hard to make out but im sure its the same, so has anyone got any clues on what has happened

 

[mfarrow]

Make sure you're connecting to the correct terminals (usually both onto the start solenoid) and that they're the right way round.

The other possibility is the flywheel ring gear's fallen off, though I doubt it.

 

[Jaybooze]

Could be a bit of, er, grit on the starter motor spindle.
Have a look, clean it, but do not put anything more that a trace of thin oil on the spindle otherwise dirt will stick to it.
PS Read your post fully,it must be the starter motor not aligning correctly or fully.
There is a lot of torque generated by a starter motor so it must be correctly and firmly fitted,but do not overtighten the securing bolts and risk stripping the threads.Jerry