noisy at 75+ miles per hour only

[cancarcan]

My Mom bought this automatic 1999 Corolla new. It has lived in Florida and has now taken up residence in Canada,Ontario. It has 38,500 miles on it,mostly driven at under 70miles per hour. As I drove this car to Canada, I noticed that it became noisy over 70mph and really noisy at 80-85. The noise remained the same from about 80 to 95mph. Putting it in neutral in the Tennessee hills it was much quieter coasting down the hills at high speed. It is not a wheel bearing, alignment or tire problem. The noise seems to be coming from the engine area. I don't understand why it is quiet up to 70? Exhaust ? Transmission? ??? Any Ideas ? I Will have a mechanic look at it but I have had numerous misdiagnosis over the years.

[jdmccright]

Without a description of the noise, it could be anything. Running that fast could be tire noise, wind noise, fan noise.... Take your pick. Wheel bearing noise is usually discernable at much lower speeds. You mentioned it stayed constant as you went above 75 to 95...leads me to fan noise, especially if the A/C was running at the time. Or could be a piece of loose plastic fascia.

We're taking pot shots here until you can describe the noise in more detail.

Hope this helps!