What else was removed? anything? If it's just the fan, shouldn't make a difference and possibly just a coincidence. If the fan relay was taken out, maybe a possibility it's causing an issue. Typically though the electric fan should be left in, and a mechanical added to it. This is part of the towing package that was available that is typically seen on the V8's. I'm not sure how well the mechanical fan by itself is for cooling.
My XJ had both. Things got too warm, or the AC was on, the electric fan would come on automatically as the mechanical just wasn't enough by itself with the AC on, or in offroad realm of things, the transmission fluid was getting far to hard, which in turn heats the rad not having it cooling enough and the temp of the engine slowly start to climb in to overheating territory. Also always had an override on the electric so once stopped with engine off, could continue to cool everything by the electric fan.
The beatings will continue until attitudes improve!
HID Quad bi-xenon + foglight retrofit