Piston Slap?

**1999sscamaro** · 01-11-2011, 02:14 PM

Hey, i have had my 99 camaro for about 7 months now and i first got it during the summer. my issue is that during the summer you could here a little knock when the engine was cold but when it warmed up it went away. when the winter hit you can hear it more now but it isnt that bad but it still some what concerns me. i know the early ls1's had piston slap issues espically the 97 years but im just curious if any one else has the same problem? during late or mid summer i plan on tearing down the block and building a engine but im just worried about it now so i dont really need it to last another year just about another 6 months.

**youngrigo** · 01-11-2011, 02:20 PM

Run a little thicker oil

**1999sscamaro** · 01-11-2011, 02:24 PM

thats what im running now, i changed the oil right before winter. the knock doesn't happen every start up either, just at certain times.

**redbird555** · 01-11-2011, 03:01 PM

they all slap lol ive ridden in every year ls1 except a 97 and with the exception of a 98 ls1 they all slapped particularly the 01-02 did it worse. In 01 gm switched piston rings and teflon coated the piston skirts which may have added to the problem. as long as its not burning a crapload of oil i say run her hard

**red98ss** · 01-11-2011, 03:02 PM

piston slap will not go away, it is MOST likely your lifters, does it sound like a diesel when it first starts. try strait 30weigt.

do a compression test

**1999sscamaro** · 01-11-2011, 06:32 PM

Yeah i realize alot of them have them im just curious if it causes problems. It hasnt had any problems and i drive it like a bat at of hell some days but i was just curious.

im almost 100 percent sure its not lifters or any other knock but you are right i should do a compression test which i might do when spring hits

**pajeff02** · 01-11-2011, 06:45 PM

As stated the LS-1 is known for cold start piston slap. It is the combination of short skirt pistons and material expansion rates that causes this. Generally, it is nothing to be concerned with and you need not take any special measures. When we first purchased our car back in 2008, my friends were a bit alarmed by the way the engine sounded at startup. Like me, they were all old school and to have an engine sound like that was a bad thing. However, once it gets a little heat in the engine, things quiet right down. I would not worry about it -- for peace of mind, there are lots of guys on here that have rolled well in excess of 150,000 miles on their cars with no internal engine issues.

**1999sscamaro** · 01-11-2011, 08:54 PM

Originally Posted by pajeff02

As stated the LS-1 is known for cold start piston slap. It is the combination of short skirt pistons and material expansion rates that causes this. Generally, it is nothing to be concerned with and you need not take any special measures. When we first purchased our car back in 2008, my friends were a bit alarmed by the way the engine sounded at startup. Like me, they were all old school and to have an engine sound like that was a bad thing. However, once it gets a little heat in the engine, things quiet right down. I would not worry about it -- for peace of mind, there are lots of guys on here that have rolled well in excess of 150,000 miles on their cars with no internal engine issues.

thanks that puts peace of mind and yeah it stops once it gets heated up. i have about 126k on mine with no engine issues and it still runs like new only problem has been with the tranny and rear end like most f bodies.

**Demon_Z28** · 01-11-2011, 09:01 PM

My 98 Camaro had no piston slap, my 01 has it... It truly will never 100% go away, but the noise goes down when it is warm. Having an exhaust cut out also makes it quieter lol.

**redbird555** · 01-12-2011, 05:00 AM

ya what he said lol i did the lifters on mine and nothing changed fwiw, mine does it bad and it runs hard just put a bolt on g35 coupe in its place last night so shes still running strong at 118k

**whitetrashbird** · 01-14-2011, 02:07 PM

As already stated, it appears to be pretty common in these engines. Mine has it when I first start it in the cold and goes away after I warm it up. No problems so far, I just take it easy on it (a good idea with any engine) until it warms up.

Dan

**Sarge** · 01-14-2011, 02:54 PM

Your choice of oil filter will have a larger effect on piston slap than going up a grade of viscosity. Go back to a 30 weight and try a WIX or NAPA filter. What filter do you have on there now?

**Mystic Z-28** · 01-20-2011, 03:11 AM

Piston slap is just more annoying than anything. It won't hurt anything. My car has it and it takes a good 15 minutes after start up to go away completely. Summertime it only takes about 5 minutes or less though, to go away. Like what was said above, go easy on it until she's fully warm.

**Sarge** · 01-20-2011, 04:25 AM

Piston slap does nothing to harm your motor... it is just annoying to some.
Only two things I have found that "helps" or "reduces" it are these.
(Keep a 30 weight oil in there. DO NOT think for one second a heavier weight oil is doing anything to reduce piston slap. HT/HS is just fine in a 30 weight.)
1. Use a High Flow Oil Filter. Wix/Fram XG/Mobil1
2. Use the TCW3 in your fuel. It washes the cylinders and we have quieted a lot of LSX motors with this easy/cheap to use fuel add.

**pajeff02** · 01-20-2011, 04:38 AM

+ 1 on the TC-W3. We run it in all our vehicles every fill up.

**Sarge** · 01-20-2011, 05:33 AM

I have no "scientific data" on TCW3 and how it quites the motor.
My theory is fairly simple....I see it cleaning the ring packs and washing the cylinder allowing better oil film "stregth"......thus a quieter motor.