My truck has been making a high pitched noise from inside the cab when first started, it goes away once it has warmed up. It sounds like it is coming from the speakers like you would get from bad plugs that don't have a noise filter. I replaced the plugs some time ago and this is a recent issue. The noise seems to go up and down with the speed, so when starting out it gets louder until the trans shifts then gets quieter. Once it warms up(after about 10 min) the noise goes away, and it seems to only happen when the temp outside is below 35, so does not happen during the day or when I leave work in the evening

Is there some sort of a noise filter that can be changed?

Thanks, Kerwin

 

Do you have an aftermarket stereo? If you do, sometimes the location of the wiring will pick-up engine noise.

 

I do have an aftermarket stereo, but have had the truck for about a year and have not had the problem until the last few days. Nothing has been done that would have affected where thewiring is at under the dash or engine bay. The funny thing is the noise goes away once the truck warms up and seems to be there whether the radio is on or not, or if the heater is on. Just seems very odd that the noise would go away once it warmed up