Diagnose my 04 F150's Rattle while on Throttle Uphill

[Stangman Jonathan]

Been experiencing this for weeks and I can't figure it out. I would like to get an idea of what it is before it gets the suspension lift/tires and other repairs so it can be fixed.


Please note, it only has happened to me uphill (specifically 208) while being on the throttle, as soon as I get off the throttle it goes away....I'm hoping it's not the worst but if its only doing it under heavy pressure going uphill, that can be a BIG problem.

You Tube

You Tube

Some Info:

- I have welded dual exhaust that doesn't move one bit, I just checked the cats and the shields and they aren't making any noise nor is the shield loose.
- I do have the ABS Light on (haven't had the chance to get it flashed to see if swapping out the rear abs sensor worked)
- I also do have one pretty messed up shock in driver's side rear but I don't think it's capable of making that noise.


What do you guys think?

[Matticus91]

That almost sounds like an exhaust leak but it's hard to tell from that video. Idk otherwise I would have thought heat shields like you said but I think that would be at certain rpm's not just under more stress.

My car actually makes a similar noise under similar conditions. And I know that to be an exhaust leak for sure. But idk it's difficult to tell from the video

[Stangman Jonathan]

Yeah I'm clueless, everything else is welded and he did it a few years ago with brand new stainless steel pipes.....I actually have 2 high flow cats that I'll be putting in and removing those 4 that it has but for some reason I still don't think it's exhaust related and I know I won't be able to hear it as much after the high flow cats lol

[mustang585]

Kinda hard to tell from the vid with the other noise. Does it sound more from the front or back?

If it's coming from the front/engine maybe it's pinging. Do you run 87 in it? I had an old Dodge truck that would ping only going up hill.

Any vibration in the steering wheel?

Check under the truck and look for anything loose.

[Stangman Jonathan]

Originally Posted by mustang585

Kinda hard to tell from the vid with the other noise. Does it sound more from the front or back?

If it's coming from the front/engine maybe it's pinging. Do you run 87 in it? I had an old Dodge truck that would ping only going up hill.

Any vibration in the steering wheel?

Check under the truck and look for anything loose.

- Sounds like from the front but I can't really tell.

- I do run 87 in it most of the time, maybe I should run better gas in it?

- Hard to tell since it naturally vibrates due to the bigger tires - since when I got it I believe

- I'll have to do that again tomorrow and see....I kicked around lots of things while under there to see if anything was loose and nothing so far.

[Matticus91]

Try running higher quality gas (shell/sunoco/etc) and maybe a slightly higher octane? Back to my theory on the exhaust leak...If it seems to be coming from the front it could be a connection from the exhaust to the cats. Perhaps a bad gasket

[Stangman Jonathan]

Yup I'll get some tomorrow....12mpg and 4:00 for 93 keeps me away from it in the F150 or otherwise I'd use it more.


Unless it's the header gaskets, I don't think it could be anything else since the dual exhaust pipe is welded right after the cats and there's no connections there, it's just one solid weld piece with mufflers halfway down the middle but all welded to the tips

[Matticus91]

Alright well how many miles are on it? I doubt it could be the header gasket but you never know. Also is there any kind of separation connection or any part with a seam that connects the headers to the cats? And I wouldn't run 93 but 89 would be fine.

[Stangman Jonathan]

probably 20k or less....I can take pictures tomorrow. I believe there may be a mounting point where the cats/headers meet, if so that could be the possibility too.

Totally forgot about that part

[JerseyShovel]

I'm kinda thinking along the lines as frank. run a tank or two of 91 in it to see if it gets better. if it still does but not as bad then try 93. also look at your tuneup stuff, plugs, wires and such.