Cold howl on accel
I could use a little diagnostic help. Have recently started hearing what sounds to me like turbo howl during cold accel.
At first I thought it may be belt squeal. Checked the belts and tensioners and indeed had a bad accessory tensioner. Replaced that and hoped for the best. Still have the cold howl. It only happens when dead cold and only on initial accel. Sounds to me like I'm starting to lose the turbo but I'll defer to you guys that are more familiar.
Included a vid link, sorry it's upside down but you only need to listen.
First I’ve ruled out turbo whine. I couldn’t hear the noise from the top of the engine but could hear it underneath. I think not only did I have a bad tensioner but I think it’s the routing/idler pulley that’s bad on the main belt. Also as I watch the tensioner while running it’s kinda dancing a bit.
Replaced idler pulleys. Still there.
Well at 200k it’s time to replace ‘em anyway. That’s the way I’m spinning it.

Guess I’ll be crawling all over it some more while wifey guns it.
I study my *** off and from what your description is, I'm leaning into power steering pump.
Your mileage and my research point right at it. They start failing at your mileage. How is your steering and do you have a note when cold when it's acting up with steering input??
Denny (big shot in the dark)
Anyway thank you for your thoughts. As I think about it I couldn’t hear the noise up top much and it might be more driver side oriented and down. I’ll look at the pump next.
Thanks again.

I can’t tell you guys how much I’ve been crawling all over this truck. It wasn’t the front of the engine at all. Was checking all the down pipes and up pipes for cracks because it was very boost related. You could play with the pedal and tell it wasn’t a pulley. No cracks in any pipes but in following the boost and exhaust patterns, boom, there it was. One of the passenger side bolt holes was empty and there was soot around it where the rest of the engine was spic and span. The rear exhaust manifold bolt broke and because there are two steel gaskets it is making a whistling sound when it gets boost.
So now my only problem is getting some time to make the repair. In saying what the dealer would charge and taking a couple days off against it, I think I’ll be taking a couple days off (though this is going to be an epic pain in my keester).
This is exactly the problem I have.
https://www.ford-trucks.com/forums/1...bo-squeal.html
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Now to drill the bolts out.
This thread has helped a bunch.
https://www.ford-trucks.com/forums/1...old-bolts.html
If you ever have to do this job just know it’s a weeks worth of work (at least for us old guys).
Ford Trucks for Ford Truck Enthusiasts
Today was bolt drilling day.
The first one would not take a straight bit into it. Kept shoving it over to the side. It came out in pieces and one side of it was pretty much welded to the threads. It pushed the bit away from the somewhat welded area. But With the help of a dremel and some new cool bits I could chew away at the welded part and finally cleaned it out with a tap and thread chaser. And that was the easy to reach hole, thank goodness. If it were the hard to reach hole it would not be good.
The second hole took a very nice center punch and I could get an almost perfect center on it. Had to go very slowly though. I had ordered some McMaster Carr reverse drill bits which weren’t cheap and had to cut down the length of the two larger sizes in order to fit behind the frame. At 3:05p I finally got the second bolt to break free.
3 days and counting. But it’s all downhill from here. Tomorrow I’ll get the manifold back on then a slow rebuild should be done Friday.
Just amazes me that there are only a few easy bolts to get in. Gotta get your attitude straight to get ‘er done.








