Piston slap at 82,000 miles ???

[OtisBlkR1]

Hello everyone, its been a hot minute since ive got on here (i guess after awhile you learn what you need to know)

with that said i got a shocker last week, my silent as the grave 5.3ltr in the Silverado developed a ever so faint "tick".. but before i go there, the only thing thats happend is a spark plug change this year, no broken plugs, 20,000 miles early, just wanted to do it..

So i change the plugs, notice no abnormal noises and take the truck 1,300 miles on vacation. Upon arriving home i detect a "tick" on the right passenger side bank.. I pulled the plug wires and found one plug a bit loose, upon tightening it down the tick subsided however never fully dissapeared.. I was perplexed and took the truck to my now retired (from professional wrenching) ASE master mechanic. He gave it one listen and says "that little bitty tick ?? that what your talking about? "Yes" Well, its piston slap, the 5.3 and 6.0 are well known for it ! Once the factory protective coating (i dont recal what he called it) is worn off many of these motors develop that little tick.. "its fine for 300,000 miles, change your oil regular and dont worry about it.. its officialy broken in..

I was blown away..

 

[Nate1979]

Blown away by what exactly?

 

[Clevy]

Piston slap in no way affects the longevity of these engines. I've got both a 5.3 and 6.0. The 5.3 slaps,the 6.0 doesn't.
The 5.3 has 290k and the 6.0 has 215k.
My guess is your oil sheared after your trip which makes the noise a bit worse.

 

[OtisBlkR1]

Originally Posted By: Nate1979
Blown away by what exactly?


that it was "piston slap" ive owned many,many automobiles with up to 230,000 miles and never had a piston slap, the fact that i have a audible tick and thats the diagnosis on such a low miliage highway truck (its a garage queen) is very, very suprising to me. Many co-workers with the same motor and twice the miles on their 5.3's have no such noise.. I guess i just got the lucky straw.

 

[OtisBlkR1]

Originally Posted By: Clevy
Piston slap in no way affects the longevity of these engines. I've got both a 5.3 and 6.0. The 5.3 slaps,the 6.0 doesn't.
The 5.3 has 290k and the 6.0 has 215k.
My guess is your oil sheared after your trip which makes the noise a bit worse.


Hey Clevy, i just did a OCI with PP and a Napa filter.. oils brand stinking new man !!

 

[Lapham3]

Pistons today really don't have'skirts' anymore-so the rocking or 'slap' is easier to happen than the'can' type shapes of old=the tradeoff made to reduce the size and weight compared to those quieter pistons of times past.

 

[Nate1979]

It is so common it even has its own website: http://www.pistonslap.com/tsb.htm

 

[OtisBlkR1]

yeah, i get that its not a big deal, and no its not noisy.. just very faint, but for a picky owner its annoying.

 

[clinebarger]

Just pray that it is piston slap, Some 5.3L's develop pitted Cam Lobes. It starts out as a tick, Then misfire codes.

This happens usually on lower mileage engines like yours.

GM has a bulletin TSB - PIP4138F for this issue.

 

[OtisBlkR1]

Originally Posted By: Nate1979
It is so common it even has its own website: http://www.pistonslap.com/tsb.htm


wow, had no idea.. this talkes about the 99-2003 models, Mines a 2006. I wonder if the problem is worse in the older 5.3's ?

 

[Merkava_4]

You need an oil that sticks to the cylinder walls better.

 

[Clevy]

Originally Posted By: OtisBlkR1
Originally Posted By: Clevy
Piston slap in no way affects the longevity of these engines. I've got both a 5.3 and 6.0. The 5.3 slaps,the 6.0 doesn't.
The 5.3 has 290k and the 6.0 has 215k.
My guess is your oil sheared after your trip which makes the noise a bit worse.


Hey Clevy, i just did a OCI with PP and a Napa filter.. oils brand stinking new man !!


Sorry.

I misunderstood then.
It is strange that it just suddenly presented itself.
Strange

 

[FL_Rob]

Hence,..this.

www.bobistheoilguy.com/forums/ubbthreads.php/topics/3569537

 

[Nick1994]

Can't believe you didn't know how common this was on GM engines. My moms 3.4L Buick has a little bit of it and so does my Grandma's 4.2L Trailblazer.

 

[OtisBlkR1]

Originally Posted By: Clevy
Originally Posted By: OtisBlkR1
Originally Posted By: Clevy
Piston slap in no way affects the longevity of these engines. I've got both a 5.3 and 6.0. The 5.3 slaps,the 6.0 doesn't.
The 5.3 has 290k and the 6.0 has 215k.
My guess is your oil sheared after your trip which makes the noise a bit worse.


Hey Clevy, i just did a OCI with PP and a Napa filter.. oils brand stinking new man !!


Sorry.

I misunderstood then.
It is strange that it just suddenly presented itself.
Strange


No apology needed sir, and it is very strange.. I change spark plugs go on vacation and develop a tick.. bugs the sin out of me..

 

[Koz1]

http://www.pistonslap.com/experts.htm
One way to check for piston slap: Remove three spark plugs, leaving number one in place. Crank the engine over until you feel the resistance of number one piston coming up on compression. Crank against compression until the piston is about half way up the cylinder. Now using the fan, rock the crankshaft back and forth and listen for a metallic knocking sound. If you hear a knock, you have piston slap and the only way out is to rebuild the engine.

So just rebuild it before it gets worse and causes even more scoring more ticks more fuel and oil consumption.
Loose tolerances and pistons built up wrong?
What is going on with GM these days?

 

[Clevy]

Originally Posted By: clinebarger
Just pray that it is piston slap, Some 5.3L's develop pitted Cam Lobes. It starts out as a tick, Then misfire codes.

This happens usually on lower mileage engines like yours.

GM has a bulletin TSB - PIP4138F for this issue.




Now that is interesting info.

Thanks.

 

[OtisBlkR1]

Originally Posted By: Nick1994
Can't believe you didn't know how common this was on GM engines. My moms 3.4L Buick has a little bit of it and so does my Grandma's 4.2L Trailblazer.


nope, "Hemi tick" yes "chevy tick" no... its new on me.. (keep in mind im not a mechanic nor do i claim to be) thats why i know a couple of good ones and have BITOG in my corner.

 

[CentAmDL650]

I have the 6.0 in an '01 Silverado. The slap has been noticeable in cold weather since about 35k miles, has 112k now. Also interesting is putting a light load with a little extra throttle causes the volume of the slap to decrease to almost nothing, and letting off the gas pedal gives it a rattlesnake sound. It lasts for about 3 or 4 minutes on mine, but it's enough that I've had some people new to riding with me tell me I've got a real quiet Duramax! Which makes me roll my eyes, but I tell 'em "you sure do know your motors!"

The factors I've heard of that are supposed to affect this are:

the factory teflon coating wears off the skirts;

the skirts are significantly shorter than the Gen I small block, allowing the pistons to "rock in the bores";

carbon builds up on the "quench zone" of the combustion chamber and the piston and goes from a very small gap to an interference;

the very small gap in the quench zone is intentional and by design, as the piston goes to TDC the squash on the zone creates additional turbulence in the burning air/ fuel mixture, which aids in completing the burn/ increasing power/ reducing gas consumption/ and lowering emissions;

the rings are low tension models for "improved" mileage because of reduced drag on the cylinder walls;

they've gone to hypereutectic pistons, which like forged pistons expand more when heated from cold up to operating temperature.

 

[Clevy]

Originally Posted By: CentAmDL650
I have the 6.0 in an '01 Silverado. The slap has been noticeable in cold weather since about 35k miles, has 112k now. Also interesting is putting a light load with a little extra throttle causes the volume of the slap to decrease to almost nothing, and letting off the gas pedal gives it a rattlesnake sound. It lasts for about 3 or 4 minutes on mine, but it's enough that I've had some people new to riding with me tell me I've got a real quiet Duramax! Which makes me roll my eyes, but I tell 'em "you sure do know your motors!"

The factors I've heard of that are supposed to affect this are:

the factory teflon coating wears off the skirts;

the skirts are significantly shorter than the Gen I small block, allowing the pistons to "rock in the bores";

carbon builds up on the "quench zone" of the combustion chamber and the piston and goes from a very small gap to an interference;

the very small gap in the quench zone is intentional and by design, as the piston goes to TDC the squash on the zone creates additional turbulence in the burning air/ fuel mixture, which aids in completing the burn/ increasing power/ reducing gas consumption/ and lowering emissions;

the rings are low tension models for "improved" mileage because of reduced drag on the cylinder walls;

they've gone to hypereutectic pistons, which like forged pistons expand more when heated from cold up to operating temperature.


Hypereutectic Pistons expand considerably less than forged ones do. When I bought Pistons for my bike the hypereutectic Pistons were actually bigger than the forged ones for my bores,though it was slight.
And the slap is due to the Pistons rocking in the bores til the engine is hot and the Pistons expand.
That's it

Since when did engine parts get coated in Teflon?