krmurley

Hey all, new to the boards and looking for some input.

For about a year I have had an on again off again issue with a moaning/buzzing sound that seems to be coming from the front end. It started with a moan on deceleration that would stop when I would brake or get back on the gas. When it would do this I could feel it in the pedals and the steering wheel. As the condition has progressed, it now seems to happen regardless of whether I am braking, coasting, or accelerating. I would guess that it occurs around 70 percent of the time I am driving, and usually starts after 5 minutes or so. It also feels like the truck is decelerating itself, kind of like an engine brake is activated when the sound is particularly loud. When coasting down the highway and the sound going, I can shift in to neutral and it will go away (at least to the point that I can no longer hear it due to road noise). Then I shift back into drive and it begins again. Occasionally there will also be a slight buzzing sound when I come to a complete stop, but I have not been able to locate it.

I have been to the local dealership, as well as a local transmission shop and both have said that they drove it and didn't notice anything. I find that hard to believe.

Some other less pressing issues I have are:
Rough idle
Surging during braking at low speeds
Hard shifts between 1st and 2nd
Hood open warning after the vehicle has sat out in the hot sun (I replaced the hood latch last year to no avail)

I also feel that recently I have had some throttle response/power issues as well

I have had many things suggested to me, such as pinion gear, differentials, power steering, U Joint, etc.

Anyone experienced anything similar or have any suggestions?

repairman54

Assuming plugs have been changes with AC plugs a rough idle can be a dirty throttle plate or a leaking EVAP purge valve or some other vacuum leak. STFT readings help with that.
All your fluids clean in the trans., T case and diff's ? Trans. fluid should be done every 50k miles for maximum trans. life as well as the T case. Cleanliness of fluids is a indicator of internal condition.
Hood latch may need adjustment or new could be defective. Especially if temp affects it I would suspect adjustment.
Both my front hubs only lasted 75k miles, and sometimes they will only make noise under power/in gear.
Brake surge is usually warped rotors. Worn, loose front hubs can warp rotors.
U joints binding can only be checked with driveshafts out.

loosemorev

I have heard the same thing on my 11 Tahoe. LT I had bought new tires and it went away. It sounded like a train horn kinda. Didn’t matter if I was in auto 2hi or 4wd the sound never left. New tires and the sound went away. I hope this helps