Got Piston Slap?

[mikelemoine]

I have an 03 Harley Edition S/C with 16K on it and have been noticing a 1 or 2 second rattle when the truck first starts up. It basically knocks until the oil pressure comes up. Being anal about noises, squeaks and rattles it drives me nuts. I think it's done it since I've had it but I had a header leak and couldn't tell until Terry fixed that for me. I guess my big question is since this is likely due to tolerances in the motor not being 100% perfect, do I need to worry about this causing problems later? If the bearing tolerances are not right will that make a VB more likely when I push the motor? It looks like my truck had a rough first 11K before I bought it. I don't race it but do like to boost it once in a while. I have a 4lb, SCT, CAI, TB, JBA Headers/Cats, etc so I doubt there will be any luck with the dealer a month before warranty runs out!! Would a pre-oiler help? I can't drop 5-10gs into installing a built motor but don't want to blow it up either, but I've never seen this on motors with less than 100K on them! Any ideas?

[dboat]

I have an 03 Harley Edition S/C with 16K on it and have been noticing a 1 or 2 second rattle when the truck first starts up. It basically knocks until the oil pressure comes up. Being anal about noises, squeaks and rattles it drives me nuts. I think it's done it since I've had it but I had a header leak and couldn't tell until Terry fixed that for me. I guess my big question is since this is likely due to tolerances in the motor not being 100% perfect, do I need to worry about this causing problems later? If the bearing tolerances are not right will that make a VB more likely when I push the motor? It looks like my truck had a rough first 11K before I bought it. I don't race it but do like to boost it once in a while. I have a 4lb, SCT, CAI, TB, JBA Headers/Cats, etc so I doubt there will be any luck with the dealer a month before warranty runs out!! Would a pre-oiler help? I can't drop 5-10gs into installing a built motor but don't want to blow it up either, but I've never seen this on motors with less than 100K on them! Any ideas?

Mike, I am sure others will post up on this one.. its not uncommon though on our trucks, there have been numerous posts on this issue on multiple boards.
I would tell you to run synthetic oil and let it warm up b4 you push the engine real hard.. but lets see what others have to say.
Dana

[PoorSvtman]

yes alot of trucks encounter this... One thing to make sure your doing is running a oil filter with a anti drain back valve... The motorcraft filters have this....

[rickgig]

I've got over 100k on my truck and can't remember a time that the piston slap didn't happen.

Unless someone else chimes in and says something else... don't worry.

[PoorSvtman]

you should hear the chevy motors mainly the 6.0 they have piston slap bad and well chevy says its fine and wont hurt anything....

[Tex Arcana]

I had it in my '97 5.4, and I have it in my present motor. THe '97 ended up getting replaced under warranty, and I ended up with a stronger motor than original. I'm not too worried about this one because once it blows up it's gett built. I've heard from alot of people who have the slap that it's not a real issue, that the motors will last plenty long.

[99WhiteBeast]

I've had it since break in and still have with 94K on the motor and its not babied- don't worry about it

[mikelemoine]

Sounds like it's just a nuisance but its still disappointing as this is a design flaw or some corner cutting at the factory. That rattling is metal to metal contact and even if it doesn't kill the motor quick, it can't be very good for it! Its a shame that the big three design some great cars and trucks but then cut corners and open the door to foreign competition. I've owned a bunch of Fords and the mod motors just don't seem as tough as the old small blocks. You can't kill them! Same goes for Dodge and Chevy. Seems the Dodges spend lots of time in the shop (they spend more on marketing than quality) and most of the GM trucks you see over a few years old look like they are sagging in the middle (cheap or too few body mounts) and of course the blue smoke puff when they start! The foreign vehicles just don't seem to have those quirks. Too bad they are boring, slow and tinny in most cases. They are getting bigger, smoother and faster so Detroit better stay on their toes or they will lose the truck market too! I'm done borching and I still love my truck but it sounds like a 72 model with 300K in the morning! Guess it takes after me, I creak and moan in the morning too!:crying:

[PoorSvtman]

i had it on my truck... put 115k HARD miles on it... all i had was a lifted head... YOu could still see the hatch marks in the cylinder.. I have pics if you want to see.

[Tex Arcana]

Sounds like it's just a nuisance but its still disappointing as this is a design flaw or some corner cutting at the factory. That rattling is metal to metal contact and even if it doesn't kill the motor quick, it can't be very good for it! Its a shame that the big three design some great cars and trucks but then cut corners and open the door to foreign competition. I've owned a bunch of Fords and the mod motors just don't seem as tough as the old small blocks. You can't kill them! Same goes for Dodge and Chevy. Seems the Dodges spend lots of time in the shop (they spend more on marketing than quality) and most of the GM trucks you see over a few years old look like they are sagging in the middle (cheap or too few body mounts) and of course the blue smoke puff when they start! The foreign vehicles just don't seem to have those quirks. Too bad they are boring, slow and tinny in most cases. They are getting bigger, smoother and faster so Detroit better stay on their toes or they will lose the truck market too! I'm done borching and I still love my truck but it sounds like a 72 model with 300K in the morning! Guess it takes after me, I creak and moan in the morning too!:crying:

Actually, it's not a major issue. What happened is the bore for either #7 or #8 at the Windsor factory was just a hair too large; and, in certain cases, the piston that went into that hole was a hair undersized (both conditions met tolerances). Consequently, on COLD startup, that piston that was a hair-small in a hair-large bore would slap a bit, until oil pressure went up and/or the piston heated up and expanded to fit the bore better. NOtice that the slap only happens on cold startup.

So don't worry about it. If you have to explain it to the neighbors, tell 'em some :Bullshit about how they assembled the engine loose so it can make gobs more power. :beer: