Cold start rattle

TTA 1077

Well-Known Member
#1
Any of you LS guys get a rattle at cold start? When the G8 sits for a few days and I start it, it seems to be pretty noisy for the first 2-3 minutes. Sound like lifters. First LS powered car so not sure if this is normal.​

 

PhillyD

Well-Known Member
#2
If this is a standard GM pushrod engine then you'll get that every day until the car warms up. GM engines are awesome performers but terrible in their lack of refinement.
 

WS6

Stay thirsty my friends
#3
Both my old 2005 silverado w/6.0 and the current GXp w/LS4 rattle like yours. I've seen technical service bulletins on it and if I remember it's not a lifter problem but rather a tensioner rattle.
 

TTA 1077

Well-Known Member
#4
Both my old 2005 silverado w/6.0 and the current GXp w/LS4 rattle like yours. I've seen technical service bulletins on it and if I remember it's not a lifter problem but rather a tensioner rattle.[/qu

Tensioner? Hmm! didn't think of that. It will go away though after warming up and only dose it after sitting for several days. I guess I'll have to look again next time I start it after a dormant period. It sounded like it was internal though.
 

72firebird

Super Moderator
#5
Both my old 2005 silverado w/6.0 and the current GXp w/LS4 rattle like yours. I've seen technical service bulletins on it and if I remember it's not a lifter problem but rather a tensioner rattle.
LS series motors are notorious for piston slap on cold starts, especially the truck motors (and even more so the 6.0L, LQ9 I believe is the engine code). It's nothing to worry about, people have put 200k+ miles on vehicles with them sounding like that on cold starts since day one.
 

92conv

Well-Known Member
#8
LS series motors are notorious for piston slap on cold starts, especially the truck motors (and even more so the 6.0L, LQ9 I believe is the engine code). It's nothing to worry about, people have put 200k+ miles on vehicles with them sounding like that on cold starts since day one.

That's exactly what it is, we had several cycle through the service dept when I was working at the dealership. As sad as it is, it's become acceptable for todays cars to have that noise on start-up. (We had a '99 Ford Expedition, that we purchased new, get bought back by Ford because of the very same thing. I was on my 4th motor when I finally had enough of it........so it's not just a GM thing either.)

I will tell you though, if it last longer than 2-3 minutes you may want them to look into it, or at least note that in your service records.......we had several 6.0 Denali's get new motors because the noise persisted beyond what is considered normal.
 

Snowman

Well-Known Member
#12
My 02 LS1 Camaro has done it since new. Meh, 10 years later it still runs great & turns 13.7 @ 103 at the track, not bad for a heavier drop top. I know it's an annoying sound, but I wouldn't worry about it. I also wouldn't mess around with additives. I run Mobil 1 5W30, no issues or leaks since new. Run the same in my 94 LT1. It's quite on start up. My 5.3L in my Avalanche is quiet.
 

tta299

White Car Fever
#13
bes i got was 13.20 with my drop top slp long tubes borla exhaust no tune! i ran 10w30 royal purple after 5k miles


 
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Snowman

Well-Known Member
#15
bes i got was 13.20 with my drop top slp long tubes borla exhaust no tune! i ran 10w30 royal purple after 5k miles


That's a solid improvement for sure over stock. I put in at least 6 passes and they were all fairly similar times. Another guy was running a 99 30th T-Top pulling 13.5 sec runs. 13.2 is decent with the heavier drop top for sure. SS in white looks good.

 
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