FLPetersen
Junior Member
So we took the truck on the first big trip these past 10 days, with Covid and all, and my short work distance, I rarely get 70+
Halfway from Lima, OH to Cincinnati I begin to hear a cyclic sine wave pattern hum. It starts soft, then grows loud (at times very) and then dissipates, and repeats barely 3-5 seconds between end and restart. It happens at or near 72+, sometimes hitting the gas will stop it for a short while, other times taking foot off gas will, but it returns.
It almost sounds like that reverb hum you get behind the engine when accelerating before the gear shifts. Hopefully this makes enough sense to someone.
I had the joy of hearing this for 10 day through the state of Tenn, until our return last night.
I did a bit of Googling, and saw someone else with a similar issue. The thread (elsewhere) had no resolution, but one person said to use the Gear Limit and shift it out of automatic to 8 to see if the sound disappeared. It did not. They then said try 7. At 7 it stops. At 72 the engine of course picks up sound as the truck is pushing the gear limit, but the cyclic hum vanishes.
I cannot believe this is normal, but I'm not sure what it might be and how serious it might be. Looking for advice. It is however not a pleasant driving experience.
Halfway from Lima, OH to Cincinnati I begin to hear a cyclic sine wave pattern hum. It starts soft, then grows loud (at times very) and then dissipates, and repeats barely 3-5 seconds between end and restart. It happens at or near 72+, sometimes hitting the gas will stop it for a short while, other times taking foot off gas will, but it returns.
It almost sounds like that reverb hum you get behind the engine when accelerating before the gear shifts. Hopefully this makes enough sense to someone.
I had the joy of hearing this for 10 day through the state of Tenn, until our return last night.
I did a bit of Googling, and saw someone else with a similar issue. The thread (elsewhere) had no resolution, but one person said to use the Gear Limit and shift it out of automatic to 8 to see if the sound disappeared. It did not. They then said try 7. At 7 it stops. At 72 the engine of course picks up sound as the truck is pushing the gear limit, but the cyclic hum vanishes.
I cannot believe this is normal, but I'm not sure what it might be and how serious it might be. Looking for advice. It is however not a pleasant driving experience.
