Please help me. During the cold snap, my car wouldn't turn over. It was towed to the mechanic who replaced the engine. Now the car won't start. Another mechanic says that the key has to be reprogrammed. Is this true? When I had a key made (I broke the other one) I was able to program the key myself (YouTube) can I do it when I change the engine???? Help Please

 

Welcome to the site.

Key doesn't need to be reprogrammed if it was working before. The module that "reads" the key is in the steering column.
Unless! That mechanic did something wrong and shorted or somehow cleared the BCM programming.

Fwiw. Why not just let the mechanic figure it out ? Since you're paying him to swap the engine out, getting it up and running should be his responsibility.

 

aboard!

I'll second George's comments, the failure of the replacement engine to start lies squarly at the feet of the technician.

Something may be loose, or still disconnected. Or in a "worst case scenario", the tech managed to damage either the BCM(Body Control Module), PCM(Powertrain Control Module), or the ECM(Engine Control Module). All of the aforementioned will cause your HHR to do a fantastic impression of a paperweight.

 

Welcome to the site , the crank shaft position sensor will need to be relearned from the replacement engine, he will need a scan tool to do this and don't let him charge you more if he didn't know this!

 

You need to provide a little more information other than it won't start.

What year is it?

What motor is this?

Does engine turn over with the key?

Are you getting spark?

Are the injectors getting a signal?

 

It didn't start, so the mechanic said it was XYZ and fixed XYZ. Now it still doesn't start?

Any chance your mechanic was wrong?

 

Are we talking the starter motor or the engine?

Kind of odd to replace an engine because it won't start.

 

Going back to the 1st post, "my car wouldn't turn over. It was towed to the mechanic who replaced the engine."

I sure hope he had a reason for replacing the engine. If not, this almost sounds like the engine was swapped without identifying the original problem.

Until the OP comes back with some more details, we'll just have to wait.

 

Duh??? Why is the OP chasing this?

To the OP: Check the BBB and see if the "mechanic" has credentials. Or is this person a "shade tree" like me? At any rate , this whole deal has a bad smell from what has been presented. "Car won't start; had it towed to a shop; engine replaced?

What if you complained of loose bowels and your physician sent you for a heart bypass???

Sounds like more to this than has been offered.

 

Check all your engine grounds and make sure they are all hooked up (and grounded in the correct places)