A little too strong imo. what i do is use the lasso tool to roughly make out the area i want the blur. then when that area is selected, i simply do the standard blur once. i then select the ocean ripple distortion and use that with the settings at 1 and 1. i do that twice. you end up with a quite realistic looking heat blur. but try adjusting the settings some as well. like 2 and 2 for your settings. (in ps that is)

Also the blur shouldn't affect the plane at all