04 chevy aveo

The timing belt broke on my aveo, destroying the engine. I replaced the engine with a used one. Now I get the car back on the road and the automatic transmissio won’t shift from 3rd gear into 4th. Is it possible this problem was caused when the new engine was installed, or the transmission was damaged when the timing belt broke?

Have you at least checked the transmission fluid?

I can’t think of a way that losing an engine to a timing belt would bother the transmission very much. It certainly is the case, however, that the engine & transmission do have to work together - especially in the sense that the transmission requires information from the engine to know what to do when.

One thought though, is that if you left the timing belt until it broke it leaves one to wonder about what other maintenance has been passed up on the car. How many miles are on it and what has the maintenance history of the transmission been? If the transmission was also neglected it wouldn’t be all that surprising for it to start showing signs of ill health.

Your first stop should be back at the place that installed the engine.

Is your check engine light on?

The car has 120000 miles on it and had a new timing belt at 60000 miles. Nothing has been done to the transmission but it was performing fine before the timing belt broke. The check engine light is flashing and the codes that came up were 2 transmission codes, o2 sensor code and engine misfire code.

If you want some better advice you need to report the actual and specific codes (e.g. “P1234”).

Either way you need to get it back to the shop that installed the replacement engine. There are probably some thing they didn’t get quite right.

Your transmission probably isn’t shifting into 4th gear because of the Misfire and O2 Sensor issue it is currently having.

Oh, and I believe the Aveo needs a timing belt every 60k miles, so it broke because it was due. You might want to look at your willingness to perform maintenance at the correct intervals from now on.