Rattle can noise when accelerating from stop

[SmallsTX]

i have a 81 k10 4x4 when i leave from a stop sign or a sop light i hear a rattle like noise until i hit about 5mph or so, it doesnt make the noise when im in neutral or park while reving up the truck.
any thoughts on what it could be?

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[fast 99]

driveshaft u joint? check got any rust around each joint.

 

[Buck69]

Do you have hub caps? Maybe a rock found it's way in or possibly a wheel nut fell off?

 

[SquareRoot]

Detonation

 

[Radiohead]

Does it have a hot air diverter valve on a stock exhaust manifold? Sounds kinda like marbles being munched when the spring goes soft.

 

[Rusty Nail]

What is the last thing you did to the truck?

 

[SmallsTX]

ok ill have to check the ujoints tomorrow. theres nothing no rock in the hub caps, last thing that was done to it was mechanic adjusted rockers, how could it be detonation if i dont hear the noise in neutral or park while reving the motor.

 

[Rusty Nail]

Cuz there is no "load" on the engine because it isn't connected to the transmission in park or neutral.
Might could get away with a timing adjustment. Begs the question "what forced the valve adjustment?"
That's likely what it is, the valve adjustment is incorrect. Lookup "predetonation".

 

[Joshua Keith]

Video would be great here. My thoughts immediately went to detonation.

 

[SmallsTX]

i had piston slap that's why there was adjustment, ill try to get a video later on today and post it.

 

[matt4426]

You mean lifter noise. Maybe the dist. cap got bumped and advanced the timing a little too much?

 

[TotalyHucked]

Adjusting rockers does nothing for piston slap. I'd be looking into exactly what he did and why. That rattle sounds like pre-detonation, like it's got too much timing in it.

 

[paul8369]

I had a similar issue. It turns out that the oil slinger on the front driveshaft (2 piece shaft on a C2500) broke its staking and just started spinning. It rattles from low speed up. Might be worth a check.

 

[SmallsTX]

heres a 4 second video i got of it,

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[SmallsTX]

Video would be great here. My thoughts immediately went to detonation.

Adjusting rockers does nothing for piston slap. I'd be looking into exactly what he did and why. That rattle sounds like pre-detonation, like it's got too much timing in it.

I had a similar issue. It turns out that the oil slinger on the front driveshaft (2 piece shaft on a C2500) broke its staking and just started spinning. It rattles from low speed up. Might be worth a check.

theres a video up now