Do all LS1 engines have the piston knock ?

**djvaly** · 11-26-2006, 03:37 PM

what do the tech people at the shop say?

**COYOTE SS** · 11-26-2006, 03:44 PM

Originally Posted by djvaly

what do the tech people at the shop say?

Who are you asking?

**98Z-28Camaro** · 11-26-2006, 04:45 PM

Piston slap is not the hydralic lifters tapping. That noise is called the hydralic lifters tapping. Piston slap is where the piston actually rocks in its bore (like a rocking chair) until the temperature of the cylinder (piston and wall mainly) reach operating temperature as which point they expand to correct tolerances and it quits rocking in the bore. It almost sounds like a rod is knocking. The tapping noise (light sounding, not a lower toned tap) is just the lifter to pushrod, or pushrod to rocker arm or rocker arm to valve stem being out of adjustment. Neither of which are a huge deal, but should be repaired as soon as possible in my opinion. But the piston slap probably doesn't need to be worried about until an overhaul or the engine fails. Just my .02 cents.

**djvaly** · 11-26-2006, 05:33 PM

Originally Posted by COYOTE SS

Who are you asking?

Coyotee SS: for u

.. so the dyno tune shop people said..?

**COYOTE SS** · 11-26-2006, 09:25 PM

Originally Posted by djvaly

Coyotee SS: for u

.. so the dyno tune shop people said..?

I had Doug Rippie up in Minnesota tune it and he said it was a lifter sticking and to use Seafoam. I used half a can with half a tank of fuel, this spring I'll use a full can with a full tank.

**z28punk** · 11-28-2006, 07:20 PM

im a newb to ls1's still. can someone post a sound clip of the piston slap noise? or is it to quiet to record?

**djvaly** · 11-28-2006, 07:36 PM

www.xxx.com/sounds

**z28punk** · 11-28-2006, 07:46 PM

sounds a lot like that 07 Z06 i drove at the dealership. lol

**MissingMyZ** · 11-29-2006, 12:43 PM

Gm aknowledges the noise but has stated that it has not been proven to cause premature engine failure.

**9t8z28** · 11-29-2006, 01:34 PM

Our engines are aluminum! (Different expansion rates than steel) Its normal!

**slpws6ta** · 12-31-2006, 11:24 AM

where you live has nothing to do with it i live in southern florida and my car has piston slap operating tepm is operating temp no matter where you live. It may take longer for piston slap to go away for people in cooler climates but operating temp is still 210 if it's 100 out you can still get piston slap

**9t8z28** · 12-31-2006, 01:00 PM

Originally Posted by slpws6ta

where you live has nothing to do with it i live in southern florida and my car has piston slap operating tepm is operating temp no matter where you live. It may take longer for piston slap to go away for people in cooler climates but operating temp is still 210 if it's 100 out you can still get piston slap

Well then it does have something to do with where you live!

**djvaly** · 12-31-2006, 01:10 PM

Originally Posted by 9t8z28

Well then it does have something to do with where you live!

when it's cold out like 30s below I mean, coupled with higher altitude (less air density) as well then the engines tend to knock a bit. my 2 cents.

**bttb** · 01-03-2007, 02:41 PM

My ss has lots of piston slap. It takes a long time after start up for it to quiet down. When weather is cold the more noise it makes.

**GatorSS** · 01-03-2007, 10:05 PM

Mine does not have piston slap.

**SSTODD** · 01-04-2007, 07:58 AM

Try a different oil and/or a different weight as some oils make the sound worse. Mobil 1 is very thin and makes more noise IMO.

**ShelbySS** · 01-04-2007, 08:00 AM

Originally Posted by SSTODD

Try a different oil and/or a different weight as some oils make the sound worse. Mobil 1 is very thin and makes more noise IMO.

So what is the best oil for an LS2?

I used Mobil 1 in my LS1...

**ShelbySS** · 01-04-2007, 08:01 AM

Originally Posted by z28punk

im a newb to ls1's still. can someone post a sound clip of the piston slap noise? or is it to quiet to record?

You'd know if you heard it...

**SSTODD** · 01-04-2007, 08:09 AM

Sarge is the oil guru but I believe he had good things to say about royal purple so I'M going to give it a shot this spring when I pull it out of the garage