Loud squeal coming from the front of the engine
 

I have an 02 F150 with the 4.2 V6 engine with 87k miles. About a week ago my engine started making a loud squeal when first starting the. The noise would come and go and only last for about 30 seconds so it was very difficult to track down. It would only make this noise when the engine was cold.

I thought it sounded like the bearing on the belt tensioner was going or possibly the water pump so I changed the tensioner and the belt first and for about two days it didn't make this noise. Then it started again so I took it to a shop.

The water pump had a slight leak so I had it replaced but on the way back from the shop the noise returned so I turned around and took it back in. The shop pulled the belt off and started the engine briefly to see if the noise was coming from the motor or possibly a bearing in the AC, alternator power steering pump etc. After pulling the belt the noise was still there. I had them pull the fan clutch as well and sure enough the noise was still there.

The shop is suggesting dismantling the front of the engine to see if it's the timing chain. But before digging any deeper into the motor is there anything else I should check first?

Thanks for any info or suggestions you can send my way.

It's possible that it is the crank shaft pulley. Check out the video in the second post of the thread below. Sound similar to that? Mine was making that same noise this past winter after a very cold "cold start" and it had been sitting for a month. I was concerned, but it hasn't made that noise since I lubed the belt some and since it's warmer now.

https://www.f150online.com/forums/v6...ease-help.html

Eureka! Yes, that's the exact same noise! Any idea what parts I need to replace? Also any idea what brings on this problem?

Thanks.

I wish I had more of a technical explanation for you. I google'd this issue this past winter when I heard the noise on my truck. It seemed like a more common issue on the 3.8 V6 in the Mustangs, basically the same engine as our 4.2. I actually found some good information about it on a Mustang forum. From what I remember, it didn't sound like a repair I'd want to take on myself, but you definitely want to get it taken care of ASAP or risk catastrophic damage to your engine. :eek: