DETROIT -

A major announcement on Thursday from Chrysler is expected to sink $200 million and bring 250 jobs to the Mack Avenue Engine 1 plant on St. Jean Street in Detroit.

Currently, the Detroit plant employs about 150 workers. About 100 of those workers build pickup truck engines. Chrysler will add a new engine into the plant's mix -- the 3.6 liter, midsize engine it now is building Downriver at its Trenton Engine Plant, in Mexico and in Dundee, Mich.

Watch: New Chrysler jobs will go to laid-off workers

The good news is demand is high for the vehicles running on that engine -- vehicles such as the Chrysler 200. The storied Chrysler Town and Country and the Durango crossover sports utility vehicle also run on it.

The reality check: While the 1-million-square-foot Mack Avenue Engine plant has plenty of room to build the engines, there is another plant, Mack Avenue Engine 2, a 650,000-square-foot plant which is right next door, sitting dormant.

Most of Mack Avenue 2's employees are on layoff. Most of those workers who have not moved to other plants will take the new jobs at Mack Avenue Engine 1.

That means few of the new jobs in Thursday's announcement will be open to new hires. Demand for the 3.6 liter engine is something to celebrate. However, Chrysler is only recalling laid-off line workers to do the work.

To view Chrysler's employment site, click here.