piston slap?

[cstm68]

anyone eles get piston slap on cold starts? my 01 5.3 gets it for about 30 seconds on cold mornings, is there anything i can do to fix this? is it hurting anything?

[clinebarger]

Very common on all LS based engines, I think the 5.7L & 6.0L are the loudest.
I had a 5.7 aluminum LS1 that sounded like it was going to come apart on cold starts, But never did even with my lead foot & a supercharger. So dont worry about it.

[Slowtruk]

He's right, very common. But, its virtually impossible to blow an LS engine up. I have a lot of experience with too many of these things. Great engines no matter what the sound.

[mixermike]

just turn the radio up a little and drive.no worries

[Slowtruk]

Most of the piston slap should go away once the engine warms up

[383longhorn]

i like mixermikes solution to the prob

[cstm68]

ok thanx i wont worry about it, it only does it on cold mornings for about 30 seconds

[Slowtruk]

yep some say its because the aluminum pistons are slightly too small when cold for the cylinders, but the noise decreases when the pistons get warm and expand

[swb85]

GM's "fix" for this when the Gen IV stuff came out in '05 was moving to bushed rods with floating pins instead of the pressed pins that the gen III motors had. My '01 5.3 slaps pretty good when it's cold.....140k miles going strong!

[67ChevyRedneck]

Mine has almost 140K as well. I hate this time of year (winter) because it can be pretty loud, but goes away like everyone else said. In the summer it's usually fairly quiet and short, or doesn't do it at all. Mine never really started to be noticable until it got up to around 80K. Doesn't burn oil and still gets the same fuel mileage it did when I first got it, so I guess it should be fine.

[Slowtruk]

I have a 2000 5.3 extended cab with 230,000 miles....still running like a champ. Ive had a few others too

[Boog]

I've seen a bulletin from GM some time in the past about the issue. It's common on these engines. I've heard some folks really get down on GM for producing something like this.
As much as these vehicles cost you would think they wouldn't knock or peck with low miles.
Does anyone happen to have a copy of that tsb from GM?

[truckdude239]

http://www.pistonslap.com/tsb/010601028.pdf

Info - Engine Knock on Cold Start #01-06-01-028 Engine Knock on Cold Start 1999-2002 Chevrolet and GMC C/K Pickup and Utility Models 2002 Cadillac Escalade (2WD) with 4.8L, 5.3L or 6.0L Engine (VINs V,T,U - RPOs LR4, LM7, LQ4) Some of the above vehicles may exhibit an engine knock noise that begins in the first 19,000-24,000 km (12,000-15,000 mi) of use The knock noise is most often noticed during initial start-up and typically disappears within the first 5-30 seconds (may last longer in extreme cold temperatures). The noise is usually more noticeable on the initial start-up when the temperature is below 10 degrees C (50 degrees F) and may be more pronounced on the first cold start following a long trip. This noise may be caused by an interaction between carbon that has formed on the piston, the piston motion and the cylinder wall. GM Powertrain Engineering, and an analysis of engines with this condition, has confirmed that the noise is not detrimental to the performance, reliability or durability of the engine. THIS NOISE DOES NOT HAVE ANY EFFECT ON THE LONGEVITY OF ANY OF THE ENGINE COMPONENTS. Important At this time, attempts to repair this condition by replacing the engine assembly or pistons is not recommended. Please share the information found in this bulletin with customers who inquire about this condition. In the event they have additional questions orconcerns, please advise your Area Service Manager. www.pistonslap

[Boog]

That'd be the one. Thanks.