Jbrew

Nah, that's not the injectors...like said above ^^

Yours sounds more like the diesel effect from the vid..to me anyway. Not sure what that's all about, - heard of it tho. The injectors are like a ticking and you have to be somewhat close to the headers to hear it. If you smell that hair burning smell, then your close enough.

Carcrazygts2

If it's only doing it when cold. It is piston slap. The later 5.4's are known to do it.

Tackle

I thought it was the earlier ones that did it and they fixed it in the later ones?

Just asking as mine makes the same noise as the ops. 2002 5.4

Ndulucky13

Mine does it when warm as well

Krack499

iTrader: (1)

Mines a 99 the op's is a 97 tackle has a 02 that's early mid and late 5.4s lol

But anyway mines worse on start up but quiets down some once warmed up doesn't go away entirely though

Jbrew

That one slipped my mind. I forget which pistons really show the problem, after a period of time..1 & 2 maybe? Well, I know there's one or two pistons that will show evidence of PS when dismantled.

I didn't think it was year specific, more a modular two valve specific. It may only be with the 5fours.

Jbrew

That could also be bad timing chain guides. Or one that's busted up.

Krack499

iTrader: (1)

I hope it's neither one of those they both sound expensive to fix

Ndulucky13

How many miles on your guys trucks? Mine has 151k

Jbrew

Here's a good question that might help if it gets answered. Which grade of oil (if any) would be better to run for engines w/bad piston slap?

1. Conventional
2. Blend
3. Full Syn

That one is hard to answer, unless you have live data.

What ever you do, DON'T run any snake-oil in these engines lol.

I have seen a engine pulled apart that had piston slap. One or two pistons (next to each other , passenger side 1 & 2) looks different from the others. I'm referring to where carbon builds up on the piston and where it's clean. It rubs a little different at stroke bottom. Pretty sure it's a long stroke 5our problem.
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If it's a Timing timing chain guide. When they bust up, some pieces may stay in place were bolted to the bock, - other pieces will drop to the bottom. Without the guide, the chain will slap against the broken guide chunks (which contact the casing when hit)...Knock knock..