What the hell IS that sound???? (1 Viewer)

[Jman]

Finally determined what that weird sound was that I've been hearing increasingly for a few months.

I had a lot work done last fall--new clutch, valve adjustment (hadn't been done in a LONG time), smog pump, fan clutch, etc. One day, after I had driven for an hour or so, I started to get a loud noise, sort of like a clutch slipping (but the truck didn't shudder), or belt slippage, or maybe like valve clatter, or, god forbid, a spun bearing (never heard one, but it has been described to me). I pulled off the highway, pulled into a gas station, took a whizz, then came back out and tried to duplicate the noise--I couldn't. This happened every month or so, it was driving me crazy--I couldn't duplicate the noise when I was pulled off the road, tools in hand.

Well, today, after hearing it on and off all week, I finally figured it out.

Any guesses? It's real simple, and real stupid.

 

[lovetoski]

Fan clutch?

 

[beaufort-fj60]

a whistling booger caused by that fresh NJ air?

 

[flowman]

Jeep liberty hung up underneath?

 

[lowtideride]

your wife in the backseat?

 

[Jman]

Fan clutch?

Not really, but you're the closest.

Turns out the belt for the WP/smog pump wasn't tensioned quite enough. When the engine got hot, the fan clutch would kick in, and the added resistance would make the belt slip and chatter. When I would pull off the highway to check it out, the engine bay would cool down enough so that the fan clutch wouldn't kick in. That's why I couldn't reproduce the noise when the truck was idling at the curb.

Of course, it was so fawkin hot last week, when I pulled over, the fan clutch was still engaging and I could locate where the noise was coming from.

Thanks for playing--they all were good answers. But Lowtide, When I have the wife in the backseat, she doesn't make that kind of noise.

 

[lowtideride]

I just had the same problem, thought it was one of the bearings going bad in something...turned out to be just a loose belt on the truck.....fixed it 2 days ago.

 

[lowtideride]

speaking of it, how tight should the belt be? i just made it tight enough to stop squeakin?

 

[LoveTractor]

I was gonna guess it was a kosher poo-flinging monkey who got his(or her) hand stuck up your muffler.

 

[PabloCruise]

Thanks for playing--they all were good answers. But Lowtide, When I have the wife in the backseat, she doesn't make that kind of noise.

Is that more of a grunting noise?!?

 

[Jman]

speaking of it, how tight should the belt be? i just made it tight enough to stop squeakin?

I know there is some standard tightness, but I just tightened it enough so that it defelcted just a bit when I pushed on it with my fingers.

Pablo, sometimes a grunting, sometimes more of a growl.

 

[Liam]

I was gonna guess it was a kosher poo-flinging monkey who got his(or her) hand stuck up your muffler.

not one of my monkeys - they are hard at work..

 

[GLTHFJ60]

I believe that the standard deflection is one inch at proper tension. Don't quote me, but that is what I would do. I believe that that standard is for serpentine systems as well.

 

[PHBeerman]

Muffler bearings for sure.

 

[Jman]

LOL, the deflection to used belt with 10 kg of force is 9-12mm in Australian states; in the USA and Canada, the Borroughs belt tension gauge reading for a used AC belt should be 80-120 pounds.

I just tension "by hand" and make sure there is about a half inch deflection.