is this what you guys are talking about? this is back from december i think. i talked to my uncle, he said his 4.6 does it too ever since he can remember, with 110k now

 

I am on motor number 2 as well and it does it and that video is exactly what it is. In the normal world, that noise would not be acceptable but both of my motors did it and my last motor did it for 60k miles before it went. The first motor died with issues not related to the noise.

Once warm mine goes away and does not occur everyday.


The oil i Run is 5w30 mobil 1 with a motorcraft filter.

 

so i had to use my phone for this so its not the best quality. and its warmer today so the noise isn't has loud. but it should give you guys an idea of what im refering too.
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sorry acf6 i didn't notice the video till after i posted but yes that sounds pretty similar to what mine is doing

 

Yeah I only get it sometimes, never after its been warmed up or is warm.

 

when we had weather around -20 the other day and i started it it sounded like little people swinging sledge hammers in there. the thing i find oddest about it is the fact that the colder it gets the worse it gets. guess i should just move south.

 

Maybe it is related to the oil being cold, my father said that was most likely it

 

First sound clip sounds a lot like piston slap, second one sounds worse than the piston slap I am familiar with. The key thing is that it goes away when the truck is warmed up which is text book for piston slap because everything expands in the cylinder enough to "fix" it. I am used to hearing it from inside the cab though never really walked around the truck much.

 

The research I've done puts the exaust manifold as the most common knock source of anything. Be it loose, bad gasket, or loose or broken studs, its the number one knock source and the easiest to miss diagnose. Next might be the crank bearings which is bad news. Did they reuse your old bearings?

 

I don't think so the approach was supposed tone a used motor with the plugs and coils swapped. Although given some of the stuff I have found since then I wouldn't be surprised if they reused the manifold gaskets and I have an exhaust leak up front but I would of thought that would cause a knock all the time not just when earning up

 

Not sure if this will really help, but didn't the mod motors have a bad problem with the exhaust manifold cracking? Not too knowledgeable on this, but if it is cracked once it gets warm and 'swells' back together it would get better.

 

i had that happen on my truck had 249 on it did it when it was cold put new engine in and now run great. knocks are for from the norm

 

Knocks are not from the norm as you say, its just that many owners either done feel like getting it fixed or fail to understand what is causing the knocks( they also hear from others that it is normal). The many ford v8s that I have owned, only a couple had knock issues and it was either fixed or the engine replaced for what was causing the knocks, it was cheaper just getting another motor from a junk/scrap yard. I am sure someone will reply saying that i am wrong but atleast i will be driving around with an engine that doesnt knock atleast on start up.

 

I've not read through this whole thread but my '06 5.4 F-250 doesn't have a knock when first starting it in the morning when it is cold out. My '00 Chevy 5.3 K1500 had a knock that got worse and lasted longer the colder the temps were. There is a whole website devoted to the GM piston slap but it didn't hurt my truck and I bought it used at 40,000 miles and sold it at 85,000 miles with no issues. It ran great, had excellent power on the highway, and didn't use or leak oil. When I got used to the noise I could hear other fullsize GM trucks give off the same noise on cold starts. It is supposed to be caused by the pistons slapping the sides of the cylinder until they warm up and expand, which reduces the clearances and subsequent noise.

 

My 2000 does it it cold weather. Figure it's just piston slap from 115,000 miles of wear on the cylinders/pistons and the short piston skirts. I use MC 5w20 and MC filter. As far as I'm concerned it's normal as I've heard most other mod engines older than 100K do it. It might not be normal as in designed this way, but common as the engine wears.

Mike