Engine Rattle at beginning of acceleration?

[Bkndsdl]

New here, and I have an '05 I5 Colorado (90K) with an engine rattle at the beginning of acceleration. I went to the CHECK HERE FIRST thread, found the engine rattle issues link, but every time I select it it takes me back to the Forums main page, so I need some info please.......

I really notice it when I pull up to a drive-through and my truck is close to a building. I push just a bit on the accelerator, and hear a noise like putting a fork in spinning metal fan blades. It stops after just a few seconds. Is this the timing chain tensioner? It is definitely not ping.....I always put the highest octane gas in it, and an octane boost depending on where I fuel up.

Any help would be greatly appreciated.......I love this truck, and I sure wanna get it fixed but I don't want to take it to a dealership and them stick me with that aforementioned fork......I can do it myself if I know what to look for.

Thanks!

[08Canyon]

I can't be sure what that sound is, but I think you are describing a typical sound of these trucks. Many of them rattle. Mine does, and others have said theirs have for the entire life of it. I don't like it, but I think it's what they do.


As for your gas, stop wasting money on high octane and additives. Your truck is designed to run on 87 no problem.

[jtenhundfeld]

I would check all of the heat shields. I just tightened mine all up but I have the exact same rattle right after start up but mine goes away.

[chevyrado08]

The ratttle is the belt tensioner guaranteed i had this problem when i first got my truck and talked to another member he showed what it was and he told me the stock tensioner are weak and a oor design search for a dayco belt tensioner buy aftermarket not stock as gm has not yet fixed the issue

[blong4133]

My truck does the same thing...Has for some time as well. I would describe it more as a hum than a rattle, but it goes away. Does it when the truck is started, and when I accelerate.

Don't think it's anything to worry about. ;)

[hurricanebilly]

same here . i have been under my truck time and time again with no luck .not any of the skid plates . at least they dont look loose.any help would be great.

[Goros]

There are 2 sources of the hum/rattle. Neither is major, and both are easy to fix.

First is the tensioner arm and tensioner pulley replacement. That fixes it a lot of the time, as our factory and OEM ones are not designed as well as the aftermarket.

The second is the exhaust heat shield, either on the manifold or on the down pipe where the exhaust is vertical for 6" or so after it comes off the block.

Usually there is a broken or rotted bolt/screw/thing that has come loose and lets the heat shield rattle against your pipe. On the manifold cover, tightening a couple visible bolts will usually correct it. On the pipe, you have to jury rig something.

Good luck.