this is my third f-body ( 97,99,01 )and the engine noise has gotten louder (not exhaust). my new '01 SS mn6 has a diesel-like sound when idling under load (like with a/c on), and a friend's 01 z-28 (auto) has a diesel-like sound when idling in drive. chevy has been no help. any idea how common this is? is it a problem? the noise is not very complimentary to the great exhaust sound Posted by SS RRR (Member # 726) on :
What grade of fuel do you use?
Posted by poSSum (Member # 119) on :
... just cold, or also when warmed up?
Posted by rbwrestle130 (Member # 545) on :
mine does it too it almost sounds like a gear noise in the transmission. I use the highest octane the gas stations have whether it is 91 or 92.
Posted by mike (Member # 1128) on :
i use only premium - 93 octane. the noise starts after about a minute of warmup (summer temps). for the first minute the engine is pretty quiet. then it starts with the 'diesel' like sound. makes the noise while in neutral and idling and also when moving (although once you get more than 10 or 15 mph you cant hear it anymore because of road noise). i stopped at the st. catherine ontario engine plant while on vacation, and was told an engineer would call me. but nothing yet.
Posted by XLR8NSS (Member # 1065) on :
get used to it, LS1 are evidently built to have a little slap, (so says's the dealership) mine knocks pretty badly too! Use the best gas you can get your hands on. i use the premium from union 76. It still knocks under load in first when warm , but not much you can do about it! like was suggested to me, turn up the radio and forget it!
Posted by P. R. Warnke (Member # 728) on :
yeah, i have heard piston slap is normal on LS1's.
That is why I have an LT1.
Posted by MOO4340 (Member # 471) on :
Get use too it, with an aluminum motor not cast iron you can expect more noise than the old days. I have talked to severals who are very familiar with then LS1 motor, they all say that is normal. One guy even had GM put a new bullet in his 2001 SS, problem was the same. Nothing to do with fuel. Try some good Amsoil 0-30 Series 2000 Synthetic Oil, let the engine warm up for about 10 minutes, makes all the difference in the world. KICKBACK 2000SS, M-6 W/HURST, DARK, BLUE MET. W/TAN LEATHER, BILLET GRILLE WITH 67'SS EMBLMS, CHAMBERED EXHAUST, KEY FOBS, DASH PLAQUE, POWER ANT., CHROME HOOD SCOOP INSERT, SLP FENDER DECALS, RACE GLAZED, STOCK TIPS, ALL AMSOIL SYNTHETICS, AIR LID WITH AMSOIL FILTER, UD PULLEYS, 160 THRERM.
Posted by mike01SS (Member # 1128) on :
been a while since i got back to this, but i found out more about the engine noise in the LS1. seems that gm changed the piston design and the new pistons have too much slap. i saw one engine ripped down to the cylinders and the mechanic showed me the rocking motion of the piston in the cylinder. also affects oil consumption, but only over 3000 rpm. chevy has authorized replacement of the pistons and rings with a new teflon-coated design and different rings. my engine will be torn down on monday (11/26) and i should have an answer if it works by friday. anybody hear of this, and what results were obtained? thanks from "not looking forward to having my engine dropped and opened up" mike01ss Posted by XLR8NSS1 (Member # 1207) on :
since my last post I have changed engine oil to the Amsoil 0-30 synthetic, and started adding a 103 octane boost to the Unoin 76 premium, and it has helped alot! Only when its below operating temp range do, i hear it, after its warm its quiet. Try the Amsoil it works!
Posted by OutpostInc (Member # 1239) on :
I don't think fuel grade is a factor here. The problem lies in the piston-to-wall clearance as stated above. It's not damaging to the engine according to most sources. I also believe that the oil consumption is related to the low-tension piston rings used in the '97 - '01 LS1's. There is a TSB for the piston ring replacement, but Chevy claims that avoiding high rpm/light load driving with reduce oil consumption.
Sorry if this is old news to you guys.
Posted by Craig Leres (Member # 931) on :
quote:Originally posted by P. R. Warnke: yeah, i have heard piston slap is normal on LS1's.
Check out the article titled "The Ruthless Pursuit of Power: The Sequel" in the January 2002 issue of GM High-Tech Performance magazine; it addresses the oil consumption and pistion slap issues in a technically detailed manner.
Posted by RHT (Member # 902) on :
Craig,
Is there someplace we can read the article online? I just placed a subscription order, but I don't have that issue in print.
My 2000 SS is using about 1 qt every 2000-2500 miiles.
Thanks, Ryan
Posted by Craig Leres (Member # 931) on :
quote:Originally posted by RHT: Is there someplace we can read the article online?
You could always order a back issue; there details on how to do this on the GM High-Tech webpage.
