Shano56

Hi guys, got an annoying issue that I want to fix, hopefully you guys can help!

I got a 1989 F-150. It's got a V-8 5.0L Automatic. Now my problem is... it has a terrible squeak/squeal/chirp every time it starts. This noise is constantly there while the engine is running, and doesn't go away until the engine turns off.


The noise is worse when:

*The truck is cold (terrible first thing in the morning, noise quiets down once it gets warm)
*The truck is accelerating (going on the freeway, accelerating from a red light, etc)

The noise is better/less noticeable when:

*It gets nice and warm. Sometimes it can hardly be heard unless accelerating/in a lower gear
*Put something liquid on the belt (I put WD-40 on the belt to see what it would do. I was planning on replacing the belt anyways so didn't really care about damage to the belt. It also goes away with some brake cleaner on the belt)
*When the engine gets warm and I'm coasting down the road, if I flip it to neutral, the sound quiets down. Gets load again when it kicks back into gear.

The noise is gone when:

*I take off the belt
*The belt and pulleys are soaked in liquid. Squeal gradually comes back as they dry off

Anyways, right now, it seems like more of an annoyance than actual danger of my vehicle exploding while driving down the road. It's also embarrassing which is why I want to get this fixed.

What I have done:

*Just replaced the serp belt.
*Just replaced the A/C bypass pulley (it was a bit wobbley, probably had a loose bearing, so i replaced it before it got worse)
*Cleaned each pulley with a cloth, brake cleaner, and a small brush

When I replaced the belt and bypass pulley, the noise was gone for a bout 5-10 seconds, and gradually came back. The engine was running for a bit, probably like 10 mins, afterwords to see if I could have better luck pin-pointing the noise, but no luck. The noise was back to its original loudness after a minute down the road.

What I think I will have to do, is start replacing each pulley one by one until the problem goes away. I can't think of anything else it could be. I got a second opinion as well, they agree. The original owner thought it could be the air pump.

I think I am going to either replace the alternator or the air pump first, because 1) what the original owner suspected and 2) the alternator seems a tiny bit noisy when spinning freely. When listening to it while the engine is running and facing the engine from the front, it seems the noise is coming from somewhere on the left side. I'm not the richest guy, so it's gonna take me about a month just to buy 1 or 2 replacement parts, but if anyone has any suggestions, that would be great.

Rouphis

The tensioner is also a wear item. I would try replacing that before go on.

-Rouphis

Shano56

Ah yes I was thinking the tensioner too, but it seemed to move smoothly. I will try this first however. Will report my findings in a week

Rouphis

In my 96, the tensioner is a spring I am guessing that your is the same. They tend to lose there springieness with age/use. 23 years is a lot of age/use.

-Rouphis

Jordan1186

I had to replace my tensioner too in my '93 F-150. Its simple to do and isn't that expensive. Have you tried removing the belt then spinning each pulley by hand with the truck off? Also check if the pulleys have a lot of play in them, I bet you can narrow it down.

F150 Leo

water pump bearing has gone bad

LobstahClaw

I had a similar problem w/ my 1990 E-150 at different times.

Once it was because the water pump was getting ready to sieze. When it finally locked up i had my answer.

Another time it was the tensioner.

The last time it was a bad build on a rebuilt alternator.

If you could scrounge up a diagnostic listening tool like a stethescope you could probably narrow it down by listening to the part that's making all the racket.

Something like this might pay for itself with the first use.

tdcarter72

If you are going to replace the belt then get a Goodyear Gatorback belt #4060895. This is the only belt that I have had that does not squeak, squeal or chirp.

Shano56

already tried a stethescope...they are all noisy! The loudest ones when I spin them freely are the alternator and air pump. The tensionier spins smoothly and makes no noise, which is why I am hesitant to replace that first. Can that be causing the problem even though it is quiet? I am hopefully getting a second job by the end of next month..maybe I will have to waste my whole paycheck buying parts

tdcarter72 I got a napa belt. It makes sense for the belt to get sqeaky over time, but I don't think a brand new belt would cause the same noise right after replacing?

LobstahClaw I tried a medical stethoscope with one of those long metal sticks at the end, that one with the headphones is cool though, thanks for the amazon link

tdcarter72

I thought the same thing about a NEW BELT when I was having the same problem with my truck. Replaced pulleys on just about everything under the hood with no luck. That's when I got a Gatorback Belt and it all stopped.