The Ex just started making a sound that I can best describe as a hiss or squel, but not as much of a squel as the belt were to make if it were slipping. It starts around 1700 rpm and gets louder as the revs increase. The truck also feels maybe a bit down on power but that just could be me not willing to push the gas as it squels louder when I do. I don't see anything leaking and anything out of the ordinary under the hood. All gauges are normal, turning the a/c on or off doesn't change anything. Nor does the radio. Any body have a clue as to what my problem is? I'm a little worried driving home if it's something potentially serious.

Thanks in advance!

 

Diesel or gasser?

 

V10. The most recent work I had done was the redhead install and an oil change. It was done a couple days ago.

 

Well have you heard a pop lately?

Check and see if a plug popped on you. It is also possible you have a few busted exhaust manifold bolts.

The V10s are known for popping plugs out of the blue.

 

Besides for the sound, everything else is normal. No coil packs are popped out and no check engine light so I don't believe it's a blown plug. That was my first thought as soon as I heard the noise and I was hoping it wasn't that. It was the first thing I checked when I popped the hood.I drove to the shop, my mechanic says it's not a broken stud, he says it would be louder. It sounds a little like air whistling through something. He thinks the cat might be partially clogged.

 

Vacuum leak? Maybe pcv hose?

 

I thought about a vacuum leak too. Would that increase with revs or stay the same no matter the revs? You don't really hear it until 2k rpm. And then it increases as revs climb. At 4k rpm it's quite loud, meaning by then you could hear it over the radio and a/c. But if the truck is in neutral, you can barely hear it and when you do its only for a second. My mechanic seemed a little stumped and said he thinks it's an exhaust issue do to the fact that you only hear it under load when there's more backpressure. Also my exhaust isn't in great shape, it's pretty noisy as it is. I think the gaskets at the front of the y pipe are gone.

 

Check your degas bottle mine does the same thing by the sounds of it.. I think once it becomes a little more pressurized it kind of has a dull screech the sound is hard to describe, mines an 01 7.3

 

I have a gas v10. Correct me if I'm wrong but I don't believe the v10 has a degas bottle.

 

Check the hoses around your air cleaner.

 

By air cleaner do you mean the air intake just behind where the filter is? Both those houses are fine.

With the ex running, I popped the hood and pulled on the throttle body lever, I can't hear anything. I did this while pulling/pushing/squeezing a couple of hoses and nothing. It only seems to do it in drive when the revs are at least 2,000. I'm starting to think it really is exhaust related. Could an old rusty Y pipe be causing this?

 

From what you have described I think that it could be an exhaust leak, just the right amount of leakage + just the right sized leak could give out a hiss/squeal/whistle. If you have a known exhaust leak at the Y pipe I would address that issue first, it may stop the hiss as well as the leak.

 

Yep. Turned out to be a clogged/damaged catalytic converter. I'm wondering if the guy who rebuilt my trans knocked it a little to hard and dislodged some of the materials inside. But I also have a few broken studs on the passenger side manifold. I'm fine with the broken studs for now, they've been that way for a while, so I had the local Meineke weld in a new universal cat for $400. After all this money I've spent on the Ex I'm debating if it's really worth keeping. I need a reliable daily driver work truck and in the 4 months I've had this beast I've already put in at least $3k. Sucks. What to do?

 

Glad to hear you figured this one out.
I think your recent surge of repair costs have been a lot of playing catch-up on issues left over from the less concerned previous owner, hopefully you have the EX pretty well sorted out now for your usage. Every used car/truck I've ever had needed some level of periodic to near constant care and expense to keep it serviceable to my standards, but they were always far cheaper than new car payments in the long run.

 

True that I have most of the major issues sorted out. But it's by no means in good condition. The rocker panels are rusting out, as is the trailer hitch. Passenger seat leather is ripped bad and needs to be replaced, there's some minor dents which I really don't care about, and a couple other smaller issues (vsm is one of them). Also, although I replaced the cat, eventually the manifolds will need to be replaced too. I'm not sure if I evaluated this ex properly when I bought it. It was relatively cheap at $3,300 but if I would have seen all this coming I would have stayed far away. Obviously things like the transmission and cat are not that easy to see ahead of time but I'm still kicking myself for not holding back and waiting for one with less rust. Or maybe I should have bought a first gen Tundra 4 door like I had originally planned. My sequoia hasn't needed a dime for repairs besides regular maintenance (brakes, tires, oil, timing belt).

At this point I'm debating selling it for whatever I can get, hopefully at least $5,000, considering all the new parts, and buying the Tundra, or just running it till it drops and not fixing anything else that cost more the a couple hundred bucks as long as the truck can run without it. What do you guys think?

P.s. sorry for offending any Ford guys with the Toyota talk. I'm not really a Ford or Toyota guy, I just like good, solid vehicles.