Loud screech noise when starting and when accelerating from a stop

CBRASSO

MEMBER
2001 FORD F-150
4.6L
V8
2WD
AUTOMATIC
220,000 MILES

It has a loud screech when starting the truck and especially on acceleration from a stop. Have changed idler pulley tensioner assembly and alternator. Also, it does intermittently at cruising speeds. Also noticed on takeoff sounds like fan is winding out and when truck shifts and fan quiets down it starts the screeching immediately. Also replaced belt. The new belt has a line of wear on the inside edge that can be seen from on top of the belt.

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6 Replies

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

Hi,

The video is helpful. I certainly hear it. If you have a line on the belt indicating wear, are you certain the belt pullies are aligned, and the belt is riding flat on all pullies?

Open the hood and locate the wear mark and then by eye, follow the belt around to see if it is not aligned on one of the pullies. Also, if you could upload a pic of the belt wear mark, it may help me.

As far as the fan noise, I'm not sure where you are located, but if it is warm, the fan clutch will fully engage when the under-hood temp reaches a predetermined temperature. At that point, it is very noticeable. When you leave off the gas, it will slow and not be as noticeable.

Now, since the noise seems to happen when you let off the throttle, check at the water pump pulley to see if there is play in the pump bearing itself. Additionally, confirm there is no contamination on the belt from coolant or other fluid.

Here is a link that explains what to look for when you have a screeching sound from a belt, but I feel you already have taken care of what is mentioned:

https://www.2carpros.com/articles/car-squeaking-noise

Let me know what you find.

Take care,

Joe

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Friday, January 7th, 2022 AT 6:59 PM

CBRASSO

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43 POSTS

Okay. So, I have a very slight in and out and up and down movement in the water pump but have a large amount of in and out on the power steering pump pulley. I have attached videos of those and also pictures of the belt which has less than 500 miles. Thanks in advance for the help. Also in the video is the idler pulley I put when belt was changed. Thanks in advance for the help. FYI, I’m in south Louisiana and pertaining to the clutch fan it’s done it whether it has been hot or cold outside. That said last week we had a 33-degree temperature drop in 8 hours.

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Saturday, January 8th, 2022 AT 9:59 AM

CBRASSO

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43 POSTS

Here are the photos of belt.

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Saturday, January 8th, 2022 AT 10:04 AM

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

The power steering pump shouldn't have that much play. The water pump has a bit more than I would like to see, but if it isn't leaking or making noise, it's likely fine.

The mark on the belt, was that toward the engine or away from it?

Let me know. I have a feeling the pump is bad. Make sure the pulley itself isn't loose.

Take care,

Joe

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Saturday, January 8th, 2022 AT 11:27 PM

CBRASSO