piston slap?

**wicked illusions** · 05-22-2006, 06:49 PM

what is a piston slap and how do you know if you have a piston slap? I know 01-02 models had that problem.

----Luis

**Bob'sWS6** · 05-22-2006, 07:47 PM

Piston slap is more common on 98-00 F Bodies then 01-02 models. I had it on my 00 Z28. Sometimes it doesn't have oil consumption issues, and sometimes it does. My Z28 was basically as loud as a diesel truck at idle. The noise use to go away, but then it just stayed after awhile. It was due to GM overboring the cylinder head walls, so the piston slaps the walls (Too loose). Never buy an F Body with piston slap, unless it is cheap, as it is costly to repair (I was quoted over $2K).

**wicked illusions** · 05-22-2006, 08:22 PM

How do I know if I have it

**Bob'sWS6** · 05-24-2006, 01:52 AM

LOL, trust me you will know. The car will sound like a diesel truck. It will be extremely loud, and inhibit some knocking like sounds. Even if you do hear those things it may be your lifters too.

If you do have it, make sure your car doesn't have the dreaded oil consumption issue. My buddy was going through a quart every 1K miles.

You can also combat it by getting heavier weight oil 20W-50, though you will lose some power.

If you are under warranty, get it fixed asap. GM can be a holes when it comes to repairing cars under warranty, so you'll have to fight with them.

**Capster78** · 05-28-2006, 05:27 PM

Just about all LS1's have piston slap. These motors are built prety loose. If you put your ear close to the intake manifold you can usually hear the valvetrain noise. Some are louder than others. I could hear my 99's piston slap from inside the car where as I have to really listen close to my 98 to hear it.