Yesterday i received 4 new 140MM case fans for my PC. They are Thermalright X-Silent 140MM. I had 2 Thermaltake 120mm's i was using before but i moved them on the cpu cooler instead so i can have dual fans on the CPU cooler. But getting to the point. After a short while a funny smell started to emit from the case. Almost a oily burning smell. The 140mm fans are rotating properly so iam thinking this is like a startup smell after being run for the first time. i did notice the 120mm that i put onto the cpu cooler didnt spin so i had to move the blade to "kickstart" it. Will this smell pass or should i be more concerned?
IMO that is not normal or good. Sounds to me as though one of the fans has a leaky bearing hub. I would take a look at the fans to see if there's any fluid (bearing oil in particular) around the hub. If so, remove that fan and RMA it. You may not be able to see any leakage due to the stickers on the fan hub but, I would want to try and isolate which fan (by smell or...) and at least take it out of the system.
My $0.02 here
That seems reassuring. Keep an ear out for strange noises though which may indicate an imminent fan failure. The concern about a failing fan is that it becomes more and more inefficient and can draw far more amperage than it is designed to - if plugged into your motherboard's header it could cause problems later. I will suggest downloading SpeedFan and every once in a while check the fan RPM's to ensure one (or more) is not slowing more than 10% from the others (helpful that you have identical fans for comparison).
Hope it helps, enjoy