Has piston slap or cold engine knock caused any problems or is it just something you have to listen to. Mine has it and was wondering how hard to push it before my extended warranty runs out.

 

If its a 5.4 they all have it to a greater or lessor extent. Varies from engine to engine, but I have heard of no slap related failures, its just anoying as hell to listen to it every morning.

 

run some fuel power in there and it should decrease that enigine knock

 

It's been over a year since I've visited F150online and We're still talking about Piston Slap ?? Good Lord ! I was thinking of trading my 99 (slapper) for a '03 Crew But I don't think I can listen to that crap every morning..I've been doing it for 4 years too long !

I really thought Ford would of figured this one out by now

 

Mine is a 99 5.4 so maybe they have got it fixed.

 

They put a master cylinder and slave cylinder kit in it and were supposed to listen to the rattle the next morning but said he could not hear it. He also said he had not heard of the problem with the 5.4. I thought it was funny. They think you just rode up on a donkey with no shoes on and they just tell anything.

 

I just run 16 ounces of Marvel Mystery oil in my regular oil and mine only has that sound for about the first 10 seconds it runs.

Figured quiet is better so the MMO goes in at each oil change now.
Mine is a 2000 5.4

tom

 

I have the slap on my 98 XL 4.6 and 99 XLT 5.4 - Both are "work" trucks that get the pi$$ run out of them. I bought both used and they had the slap. Both had sevice records that showed regular maintenance with good convential oil. Both clanked like crazy for about the first 15 seconds in the mornings when it was below 60 degrees.

I put synthetic in all my equipment. My opinion is that it is worth the extra protection. The slap is a minor tap when you crank either of these up now. I have used synthetic in my 99 Lariat since it had 3K - never herd the slap (I am scared to put dino oil because it will probably sound like it is coming apart).

I also believe in cleaning the IAC and PCV/elbow every 30K. The Ford has a few issues - the others have their own. I beieve I have the best built truck for the way I am using them.

 

I've had no problem with my 2000 F150 with the 4.6L, however my dad has knock on a cold morning in his '97 Yukon his solution, run 10W-30 instead of the recomended 5W-30. Gets the oil flowing more freely in the morning......