Knock with high rpm's

[WVRigrat05]

Maybe I never payed attn before, but when I get to 2800+ rpm's, I hear a knock or rattle, sounds kinda like an old Detroit. Blowby is a hair more than it used to be but still normal by far (I think)
I never noticed it until the 4600 rpm run to nowhere.

seems like it lost some top end, but I drive something a week and I think it's lost power, any chance I bent something in the valve train?

Thought about tearing it apart but if I do that, I know I'll be stuffing more junk under the hood I don't need right now.

 

[02greysixer]

Sure it's not just the pilot injection turning off?

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[Chevy1925]

4600rpm doing what?!

 

[WVRigrat05]

The rev limiter is 4200, apparently it's 4600 in 4 wheel drive. The shift fork and slide collar came out last days off and I couldn't make it up a hill out of a nowhere hollar to camp. My friend came to pull me out so I didn't have to rape the truck but it was so slick I still had to.

I started off easy and when I realized the big bastard hooked to me wasn't much help I just started going through the gears. Didn't realize how high it was revving until I started moving and looked down.

 

[WVRigrat05]

Sure it's not just the pilot injection turning off?

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I thought so but it wasn't that loud before, may have an injector out. I need to get my auto cal fixed so I can get some logs and check the balance rates.

My LLY sounded like a bag of hammers when the injectors was out, this trucks had clean fuel and new filters every 3-5k. It's still possible.

 

[Chevy1925]

damn thats a good way to bend push rods or float and hurt valves

id do a compression test or leak down test to see in any valves got hurt. bent push rods would be pretty noticable with excess valve train noise or a flat out miss on a cyl

 

[WVRigrat05]

No miss, no intake thump, truck rattles louder in gear at idle but silent in park. I'm gonna see why the limiter went to 4600 in four wheel drive.

My LLY had no rev limiter and it saw over 5 grand a couple times, it was either tough or I didn't care enough to pay attn.

Which one would be more beneficial, the leak down or compression test? I'm thinking compression test but I don't know.

 

[Chevy1925]

Leak down to see if you have leakage where you shouldnt

 

[WVRigrat05]

I'll have to look that one up, I don't have a clue how to do it.

 

[duratothemax]

[partially] sheared cam pin.....?

 

[WVRigrat05]

I hope not, any way to tell without tearing the front cover off?