Over a half dozen subway lines are experiencing delays throughout the transit system Friday morning, with problems ranging from mechanical issues, signal glitches and malfunctioning doors, the MTA said. 

Customers on the 4, 7, E, D, J, Z, L and N were all seeing slowdowns during their morning commute as of 8 a.m.

Currently, Southbound 4 trains are running with delays after the MTA addressed a mechanical problem on a train at Burnside Av.

They have since resumed making local stops from Bedford Park Blvd-Lehman College to Burnside Av., the MTA said. 

Northbound D and N trains are running with delays while the MTA addresses a signal problem near Coney Island-Stillwell Av.

J and Z trains are delayed entering/leaving Jamaica Center-Parsons/Archer while the MTA deals with a mechanical problem on a train at that station.

Meanwhile, 7 trains are running with delays in both directions as the MTA addresses a door problem on a train at 61 St-Woodside.

Southbound E trains are delayed while the MTA works on a door problem on a train at 50 St.

Finally, L trains are running at slower speeds in both directions while the MTA handles a signal malfunction near Atlantic Av and Jefferson St.