loud screeching sound at acceleration going up hill

[jmonsrvr]

hello, i have a loud screeching sound thats under the front part of the truck. it only happens when punching it on the freeway going up hill. on the short little hill climb for my house there is no sound when i punch it. ...im pretty sure its not that cats. any ideas. other than that the truck runs fine....95 disco 1

cheers

by the way i just got a valve job

 

[Andrew Homan]

Loose belt? if the noise is when the engine down shifts or is under load the belt may be slipping.

Cheers Andy

95 D1

 

[jmonsrvr]

is it possible that it would sound like its coming from the bottom front of the truck?

yeah it only happens while accelerating up hill...so under load. other than that it sounds fine....is there a way to check?

 

[billmallin]

I'm with Andrew... sounds like a loose belt.

 

[jmonsrvr]

how can i check to see if its loose? can i pull up on the belt and if it goes up past a certain point then its to loose? or do i need to check the actual tensioner...? i do not have a torque wrench...not sure if ill need that.....
thanks for the replys.

 

[Andrew Homan]

I don't know the spec but a single serp belt usually is tight. Check the condition first see if it is cracked and glazed. they usually have a tensioner that keeps them the correct tension, check that as well. It's kind of a spring load thingy with a pulley on it. sure sounds like the belts bad to me.

Cheers Andy

 

[jmonsrvr]

the belt is fine...no cracks. and its only a few months old. i dont think a bad belt would cause the noise. but a loose belt would. i will check it out and see....not sure where there the tensioner is and how to tighten though...any help

 

[jmonsrvr]

yeah thatsw what i thought..it has a tensioner that automatically tightens the serp belt...right?

how do i tighten this

 

[Louis Juarez]

The tensioner is spring loaded. You don't tighten it , but you do turn the belt tensioner pully retaining bolt Clockwise to release the tension using the correct box end wrench or socket and breaker bar....Caution !! there is a lot of torque on that spring....watch out for your fingers and hold on to the wrench.

 

[jmonsrvr]

i listened to the sound again and its like a "metalic" rattiling....only when accelerating under stress...like punching it on the freeway...or punching it going up hill on the freeway...not so much punching it just heavy accelerating

 

[BaldEagle]

my disco made a sound like that only when going up hills and under stress. it was the tbox running dry. check that just to be careful

 

[davidz]

i would check the motor mounts, if you break a drivers side mount, under hard accelaration the engine will raise and the fan will hit the fan shroud causing a pretty nasty sound. open the hood put a foot on the brake and power it up and see if the motor raises. it will move alot if the mounts broke. pull the top part of your shroud off and look for marks on the underside from your fan.

 

[jmonsrvr]

yeah its not the motor mounts....

i will check trans fluid. today.

 

[brianrufener]

is it a rattle or more like a pinging sound?

 

[Eric N.]

One other thing to check while you are looking at it is the front and rear U joints on the drive shafts and the exhaust for leaks.. U joints can make a noise like you describe.

 

[jmonsrvr]

you know i guess its more of a pinging than a rattling...

 

[billmallin]

Dood...

... how are we supposed to help you?

I quote:

"i have a loud screeching sound thats under the front part of the truck.... "
"i listened to the sound again and its like a "metalic" rattiling.... "
"you know i guess its more of a pinging than a rattling... "

When you figure out what sound your truck is making, let us know...

 

[jmonsrvr]

bill....pinging...rattling..somewhat the same. also if you have had these symptoms beofe than you know what kind of ballpark sound i am talking about...

anyway after spending a lot of time looking for the cause of the sound i decided to check the plugs and wires...turns out one of the plugs was not gapped correctly and this was causing the pining sound. sound is gone now.

strange because the sound that it was making would not have lead me to a plug

 

[BaldEagle]

bill seems grouchy......

 

[jmonsrvr]

bald eagle, yeah he does seem a bit grouchy...maybe its because his truck didnt "ping" or "rattle" like mine....

cheers and thanks for all the replies..