Rattle noise at start of acceleration

[Doozer]

I've had this rattle noise that is slowly getting a little louder as time goes by. I have 47k miles and it started about 6k ago. It happens the first 1/2" -1" of throttle and then seems either go away or drown out as I speed up. Usually more noticable at slower speeds. It sounds a little like playing cards hitting bicycle spokes but not quite that loud.

I pretty sure its throttle related because it doesnt not matter what the RPMs are, brakes dont change it, and it does not matter what gear its in. I can hear it if I let off the throttle completely at 50+mph and then lightly re-accelerate? Very odd.

Its not a tick its more of a flutter or rattle.

Thanks

[Longhaultransport]

If it was a gas motor would it sound like spark knock?

Diesels have a sound like a spark knock at light throttle.

[Doozer]

Originally Posted by Longhaultransport

If it was a gas motor would it sound like spark knock?

Diesels have a sound like a spark knock at light throttle.

Maybe a litte. I've had a 6.9, 7.3,6.4 and not to mention a 1952 Cat diesel motor on a D6, and New Holland tractor. I pretty familiar with the diesel rattle and this does not sound like one.

If I was to compare it to a gasser noise I would say it sounds something loose in a valve assembly. Maybe its an injector.

[Shadrack]

Mine is starting to do the exact same thing..... any ideas?????

I swear it sounds like the valves are going to fall out of the damn thing or throw a rod out the side of the block. Been doing that for about 3-4k miles now and it's getting louder. Almost sounds like an exhaust manifold gasket leak to be honest.

[ThirdCoastStroker]

I have heard the exact same thing in my truck for the past 4 or 5 months...i bought the truck with 70k on it and i am now at 82k...and it only happens with real light throttle if i mash it i dont hear it....no matter what gear i am in it always does it, some days are louder than others

i just purchased and extra care extended warranty so i will be taking the truck in soon and i will see what they say

[deerhunter89]

I heard it sometimes to. On my 6.4 sounds like the rattle is up by the windshield in the lower left hand coner. I was I knew what it is.

[Shadrack]

I would be curious to see what they have to say about it. Sometimes it is VERY loud in the cab, and when I pass a vehicle I can hear it rattling/knocking/pecking/whatever when I pull up beside them under throttle. Sounds like it is coming from the drivers side exhaust manifold area. Sounds like severe valve rattle to be honest. But you can't hear anything at idle, only under load. My dealer told me I was just hearing things basically when I mentioned it to them, lol.

[ThirdCoastStroker]

Maybe its nothing....as many people here are hearing it on there truck once you rack some miles up on the truck...at least thats what my gf tells me im crazy because i hear all kinds of stuff on the truck and she cant hear any of it

[Pthompson]

My 01 7.3 does the same sound and it has 175,000 on the clock. Sounds like it is coming from the left side firewall/dash area under light throttle. Doesn't matter what speed I'm going or anything like that. Just whenever I apply light throttle. Hard accel. no sound. ?

[jhowell]

Thats funny, my wife says you can hear that but you can not hear me! WTF!!!