Cold start engine squeal

when I start my truck first thing in the morning I get this engine squeal. Im wondering if this is my serpentine belt or if it is something else? If i let it run for a few minutes it goes away, but Im curious if changing out my serpentine belt would stop this noise. See video below. Let me know your thoughts, Thanks!

https://www.youtube.com/shorts/I9c8aWG3A6U

 

Why is the belt so glossy? I'd definitely start with the belt.

 

Im not sure.... and Im also not sure when the last time it was replaced. Im starting with the belt, but didnt know if it might be a pulley or bearing or something else.

 

Cause it’s 15 years old

lol

 

I think its the humidity difference, its 40% here and its considered high lol

 

If you have 100,000 miles or more on the belt replace it yesterday. If it breaks on you and leaves you stranded on the side of the road it can become an expensive PITA. This isn't one of those repairs that is an easy to DIY on the side of the road. And it could cause further damage. Ask me how I know.

 

Im waiting for the belt to come in. Changing it asap.

 

Is yours auto or manual? I get a similar squeal on mine that goes away once I push the clutch in. If you have an auto disregard lol.

 

I got a manual 5 speed.

 

I’d do the tensioner too just to be safe. Mine has 190k. I did the belt in the summer (high humidity) and a few weeks later the squeal came back. Turned out to be the bearing in the tensioner pulley failing so I did the whole tensioner assembly, the spring inside also softens over time/mileage. The idler pulley bearings can fail too and you can buy those pulleys or bearings individually, fairly inexpensive.

I’d vote to start with belt & tensioner. If it persists afterwards you can spray some WD40 on the other pulleys individually until you find the culprit (don’t get any on the belt or surface of the pulley). Hopefully it’s not a more expensive problem like ac pulley, alternator pulley, power steering pulley…

If the belt you take off is worn but not damaged I recommend to save it in the truck somewhere under seat or in one of the back seat cubbies in case you break a belt in the future u can install the old one to limp it to safety and not be stranded.

 

With engine running, try and spray water on the belt. First on the outside, then the inside. If noise stops or significantly changes pitch, then squealing is most likely the belt. If the squealing hardly changes pitch, it is most likely a bad bearing.

When you have the belt off, check each pulley-bearing for wear. Rotate each one gently; it should spin smoothly. Then, move each pulley side to side and fore and aft. Except for the PS, there should be no play. The PS may have a 1-2 mm fore/aft movement. Test each pulley-bearing that the belt touches.

In general, it is good preventive maintenance practice to replace the belt and hoses by 150K. Since you’ll be doing a coolant change at that mileage, I’d also replace the thermostat and cap.

 

when did you last replace your rotating assembly

 

Thanks for the info. Im changing the belt today and will keep all that in mind moving forward.

 

Im the second owner of this truck, and I've never replaced the rotating assembly. I will look into it, thanks

 

Update: I replaced my serpentine belt, as well as my water pump and the cold start squeal is gone. Thanks everyone for your input.

 

What caused you to think it was the water pump?
Mine has been making the same noise for a long time but it goes away during winter, oddly enough. I’ve already replaced the belt. Tensioner, A/C compressor, alternator and all the idlers. Frustrating.

 

I had a very slow coolant leak where you could see white dried up coolant drops below the water pump. The coolant would slowly leak and drop onto the belt area which would then cause the squeal. When was the last time you replaced the fan clutch and blades? The fan clutch could be whats causing the noise. I'm surprised it goes away in the winter as my noise mainly came during first start in the morning.

 

I’ve never done the clutch and blades. When it’s warm out, it’s always squealing.

 

Thats strange. Mine is always when its cold in the morning. Once its warm, it didnt happen. Id do a bit more research on the fan clutch. But id also look at if you see any dried up coolant below the pump. It will dry white on metal.

 

Mine also has a high pitched squeal on cold starts, really only in winter and goes away mostly in the summer. Didn't notice it much until I started using a remote starter as I can hear it from the outside more than inside but it's been doing it for over a year now, and belt and idlers were all replaced with OEM. Thinking at this point I should go ahead and do the water pump and fan clutch as I'm almost at 200k anyways