2006 Frontier XE with the 2.5l engine automagic trans 256,000 miles
I changed the front u joint and the center support bearing. After that I noticed a noise that sounded like a poltergeist howling away. The noise changes with throttle pressure, independent of road speed, and goes away after a few minutes. It only makes the noise when rolling.
Immediately went back and had another look at the driveline. I jacked up the truck and ran it through the gears and no noise that I could hear from under the truck.
Next I went under the hood and found that a piece of the fan shroud had broken and had evidence that the broken piece was rubbing on the belt drive. I thought that air passing through the radiator may be pushing the loose piece against the belt drive. I removed the piece and went for a drive. The noise is still there.
In a past life I had a faulty alternator that made a similar noise. I got a cigarette volt gauge and put it in the lighter socket. The volts maxed out at an indicated 12.3 volts and never changed. Since the alternator had never been changed I got a new one and installed, now indicates 14 volts. BTW the clutch pulley on the old alt was seized. No change in the noise.
Next I looked at the idler pulleys and belt. Most pulleys felt OK but tensioner pulley had a rough bearing. The back of the belt was shiny but the grooved side looked OK. I did feel the water pump and it was smooth and free. I replaced all of the idlers and the belt. No change in the noise.
While everything was apart I inspected the fan clutch and noted that the clock spring was missing. I installed a new fan clutch and the fan looked OK. Took it for a test drive and the noise is still there, just not as loud.
Though I don't suspect the transmission, I checked the oil level. The oil is clear, no stink or burn smell, and it is at the full level.
On a long shot, I did pull the rear wheels and found a rock in one of the rotors. Noise still there. I have not pulled the front wheels yet.
Right now I'm stumped. Any suggestions.
I changed the front u joint and the center support bearing. After that I noticed a noise that sounded like a poltergeist howling away. The noise changes with throttle pressure, independent of road speed, and goes away after a few minutes. It only makes the noise when rolling.
Immediately went back and had another look at the driveline. I jacked up the truck and ran it through the gears and no noise that I could hear from under the truck.
Next I went under the hood and found that a piece of the fan shroud had broken and had evidence that the broken piece was rubbing on the belt drive. I thought that air passing through the radiator may be pushing the loose piece against the belt drive. I removed the piece and went for a drive. The noise is still there.
In a past life I had a faulty alternator that made a similar noise. I got a cigarette volt gauge and put it in the lighter socket. The volts maxed out at an indicated 12.3 volts and never changed. Since the alternator had never been changed I got a new one and installed, now indicates 14 volts. BTW the clutch pulley on the old alt was seized. No change in the noise.
Next I looked at the idler pulleys and belt. Most pulleys felt OK but tensioner pulley had a rough bearing. The back of the belt was shiny but the grooved side looked OK. I did feel the water pump and it was smooth and free. I replaced all of the idlers and the belt. No change in the noise.
While everything was apart I inspected the fan clutch and noted that the clock spring was missing. I installed a new fan clutch and the fan looked OK. Took it for a test drive and the noise is still there, just not as loud.
Though I don't suspect the transmission, I checked the oil level. The oil is clear, no stink or burn smell, and it is at the full level.
On a long shot, I did pull the rear wheels and found a rock in one of the rotors. Noise still there. I have not pulled the front wheels yet.
Right now I'm stumped. Any suggestions.
