Capn Pete

Hey everyone..........

Well, I got the January 2003 copy of "Hot Rod" magazine for Christmas, and in the back in their "Pit Stop" section, there was a letter sent in from a mechanic at a GM dealership detailing how to "temporarily" cure the LS1 piston slap.

Here's a copy of the article. I'm really curious if this would actually work?? I mean, it sure would be nice to quiet down the engine a little.

Since it's winter and cold outside, I don't have the ambition to do this right now, but if anyone decides to try, let us know if it works.

Blackout96

Been there done that.....still f'n there.....

RamAirBird2k2

/rant on
I doubt that with only 3521 miles on my car I have carbon build up, sounds like another dealer service scam to "fix" a problem that should never have been allowed to occur
Fortunatly my piston slap goes away when the car warms up, but others haven't been so lucky, you would think for the price we paid for these cars they would fall over themselves to FIX THE FAWKIN PROBLEM, and not offer some temporary BS "solution"
/rant off
Thank you, you may now resume normal posting

pkincy

Uuh, piston slap?? What does it sound like. Any of you folks started up a car with forged pistons. Does it sound like that?

I thought complaints about "my car makes too much noise" was exclusively a Vette owner phenomena.

Perry

RamAirBird2k2

If LS1s came with forged pistons and IIRC they don't, then the noise would be acceptable.
Yes I do know what forged pistons sound like the second car in my sig (the Iroc) has forged pistons

Capn Pete

So you tried this and it didn't work?? Hmmmmm, then I guess that guy was just trying to promote that "GM Engine Top Cleaner" and convince people to do so every ~20,000miles?! Oh yeah, and "do an oil change at the same time" --- so it's a good scam?! (or is there any truth to this at all??................anyone else tried?? ).

psychocabbage

I dont think I have it.. but from what all I have read about this, I would think this is more of this one dealers scam.. Mainly becuase so many people have had it from day one.. Shouldnt be carbon build up of sufficient amount by that time..

JimMueller

Well, the oil change after using SeaFoam or Top End Cleaner is recommended. The oil will potentially have a lot of contaminants in it from the cleaning - which you don't want to remain in the oil.

So if you don't want to do the cleaner, no need to change the oil prematurely.

I used spray GM Top End Cleaner this past fall (10K miles ago)after repairing a head with a bent valve. We put it in through the throttle body, though. Didn't have any piston slap before/after, but I have acquired some as the weather has gotten colder. It goes away after warmup. I just don't beat her hard until she's warm - the engine that is.

I know when I started the engine after letting it sit 3-4 hours, the most disgusting fumes/aroma came out of my exhaust. Then the fun part was blowing it out at WOT

Drew778/94Z

They're a much better way to clean the carbon out, you spray it through the TB.

What's it called, oh yah N2O

I clean out the carbon all the time, still have the slap slap slaping.

Topless TA

I used the seafoam through the vac hose from the break boost

IN A WELL VENTILATED AREA

1) warm car to operating temp
2) disconnect hose
3) hold funnel in hose end
4) TRICKLE seafoam into funnel
5) after using 1/4 bottle fast pour the remaining 1/4
6) turn off engine and let stand for 5 minutes
7) start engine and alow to idle for 15 minutes
(lots of white smoke)
8)enjoy

I have done this on several cars Chevy,Pont.,Ford,BMW,Dodge,Jeep & Fiat it works well and especially in engines with higher miles it make a noticible difference

phil1001

this article is right with the carbon, i picked up a 5.3 engine that was warantied and it turned out that the noise was coming from carbon buildup on the pistons.

Mindgame

The problem is generally in the bore to piston clearances. Chevy says that the 'slap' is normal and has to due with the hypereutectic pistons but that's garbage.
We pulled a friends LS1 here last month (it was a slapper) and it had excessive bore-to-piston clearance on 2, 6 and 8. My 2001 C5 shows no signs of slap when cold but some other guys in our club have the slap. I think it's a quality control issue more than anything else.

-Mindgame

pkincy

The beauty of the brittle hypereutectic pistons is that they do not expand much when heated. So the clearances can be very tight. And if they are not than you will get the same sound you do with an engine with forged pistons, but it will not go away when the engine warms up.

I guess I should be grateful for too many 105 howitzers and helicopter turbine engines in my younger life as I simply don't notice those subtle mechanical noises.

Perry

2002Z28SSConv

I always had the noise. Ever since it had 0 miles. Sounded like a deisel.

I put Amsoil 10W30 in it 10,000 ago withan AC Delco PF48 (stock filter) There wasn't a change.

When I changed the filter last, I went to a PF58.

Today I changed the oil to 5W30 with a PF59 filter. The noise is all but gone now. You can barely hear it at all and that's just for a minute. This was a definate improvement. I know the PF59 filter has a better drain back valve than the 48/58's do. It's made for the Escalade and they supposedly knock profusely when the 5.3 liter (PF58) filter is used.

So, whether it was the filter or lighter oil... who knows? But something is definately making a difference now.

Capn Pete

A lot of people swear that the lighter weight oil actually helps quiet the noise down, so I think for my next oil change, I'm going to switch back to 5W30 and see if there's any improvement. I've been using Mobil 1 ever since the car was new, but in an attempt to quiet the engine down, I used the slightly heavier 10W30.

I find it hard to believe that the oil filter would affect anything. I mean regardless, the car always has good oil pressure, but I'm willing to accept anything as a cure for the knocking and ticking at this point!!