After two discussions with Maintenance Control about indications they were getting in the cockpit being related to a number two Engine Anti-Ice Valve deferral; a B737-700 Captain was notified that the MEL maintenance procedure had been incorrectly performed by Contract Maintenance.

Narrative

We picked up a B737-700 aircraft. The outgoing Captain informed me of the MEL item on the aircraft. The maintenance was done by Contract [Maintenance] a few legs prior to us receiving the aircraft. The MEL involved the number two engine cowl Anti-Ice Valve being locked 'Open' by Contract Maintenance. There were many operational concerns resulting from the write-up. We complied with all operational items but had questions resulting from the indications we were getting in the cockpit. We sent a message to Maintenance while enroute trying to explain our cockpit indications and looking for some help understanding the indications. Maintenance just reiterated the MEL write-up and was no help. With no Maintenance [at our destination] except Contract Maintenance; we continued on to [the next station. After landing there; I again contacted Maintenance Control restating my concerns and questioned if Contract Maintenance done prior to receiving aircraft was performed correctly. Maintenance Control agreed with me and we contacted Contract Maintenance to see if indeed the Contract Maintenance was performed correctly. I gave up the aircraft there to the follow-on Captain. I informed him that Contract Maintenance was called. This Captain later called me. He informed me that indeed the maintenance was done incorrectly. [To] prevent [this]; anytime maintenance is performed by Contract [Maintenance] and left on a yellow sticker it should be reviewed by Company Maintenance when transiting any Company Maintenance Base or Station.