B737-800
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Confusion; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Chart Or Publication; Human Factors; Incorrect / Not Installed / Unavailable Part
I started my service on a B737-800 aircraft while another mechanic was checking the IDG oil level and Differential Pressure Indicator (DPI) on # 1 engine. Another mechanic was to start the fuel nozzles replacement. After I completed my 1-Service; I noticed # 2 engine cowlings opened up so I figured that must be the engine getting the fuel nozzles. I found one new nozzle at the In-station for our plane so I brought it in the leads office and told the other mechanics there were three missing as we were to replace four nozzles altogether. Our lead was notified and more nozzles were ordered and they finally arrived around 23:00; so one mechanic took the left side of the engine and another mechanic took the right side of the engine and began removing the fuel nozzles to replace them. I was the third person so I was handing tools to them and getting whatever they needed. After the nozzles were replaced I helped to safety all the bolts on the engine that were removed. After inspection had looked the engine over for safety and security I closed # 2 engine cowlings. It wasn't until the next day that I was informed that the nozzles were the wrong part number and it was supposed to be done on # 1 engine.  I had never looked at any of the paperwork to verify the other mechanics with part numbers or which engine we were to work on.  Boeing 737-800 Maintenance Flow; Deferred Maintenance.  [Recommend] Make our Air Carrier paperwork more clear on which engine they want work done as it is very confusing. I myself; have had a problem in the past trying to figure out which engine they want worked on. The part numbers should of been checked on the new Nozzles and compared to the IPC; and then double checked by another mechanic.
An Aircraft Maintenance Technician (AMT) was informed the fuel nozzles that he and two other Technicians had installed on Number 2 Engine were not only incorrect Part Numbers (P/Ns); but the nozzles were scheduled to be installed on Number 1 Engine. Technician noted the paperwork for their B737-800 aircraft was confusing and not clear about which engine required work.