Police are not calling the driver a suspect but they are urging the driver to come forward as investigators believe the person could have valuable information about the illegal explosives.
The vehicle is a white van spotted near the underpass at Olive Street and South Caln Road around 4 p.m. on Monday, which is the same place police found a pipe bomb that was detonated.
Another pipe bomb was found Tuesday about a half a mile away at 14th Avenue and Olive Street. That one did not explode.
Investigators say these two bombs appeared to be homemade.
Caln Township police are urging anyone who may have information to contact them.
Authorities also say residents will see an increase in police presence in the area as they continue their investigation.