quickchrome2000

iTrader: (3)

Well my car just said **** you, and started to knock, A STADY TAPING SOUND SO I'M GUESSING ITS A ROD,. long story: I just got a truck last Friday so i parked the 2000 z28 and been driving the truck , this morning i started the z28 an damn damn damn a ******* knocking noise under the hood fuuuuck. it was running fine before no ******* warning or nothing , just like that. did the ******* car got jealous lol, i changed the oil like 100 miles back, and the gas tank is full with ******* premium gas fuuuuck. engine has 115 000 miles and i drive like a grandpa, never raced or burned tires so why is this happening to me why why why / end rant

Now fellow ls1 tech ers any ideas where to go from here? I really liked the car

I posted this on the Texas section but this may be a better place

msydow

if you have some cash rebuild it. i have a couple stock cranks and rods. wouldnt cost too much to go back stock with it. you could buy a short block from someone, but you never know what youre gonna get. where exactly are you located?

kevins2000LS1

iTrader: (11)

In the same boat as you now. Mine started sunday

joecar

It might just be some of the lifters making noise.

IWGF

iTrader: (6)

Have you compression checked it yet?

blue98Z

iTrader: (29)

It could be just lifters. Dont assume the worst yet. Did you let it run long enough to see if it goes away shortly? Also, do a compression check. I bet it's just a lifter from sitting. That is quite common. They just had time to bleed down since it sat longer than overnight.

quickchrome2000

iTrader: (3)

@ msydow no don't have cash, a mechanic that i know since 1996 went to look at it and just by hearing it said it can be fixed but it wold be better if i get a new engine cause if it gets rebuild it wold do the same in say 25 000 miles. i live by Dallas
@ kevins200ls1 yea this sucks big time its a fun car to drive.
@joe car i was hoping it was that or the oil pump, but the mechanic don't think so, oil presure is normal....cold 45 .......warm 25
@Iwgf , no haven't done anything yet
@blue98z, no i didn't let it run yet, first time i started it, the knocking sound started and i turned it off within 4 seconds, I tried to re start to See if it wold go away, but the battery went dead. second time i started it was when i jumped start the battery , for about 15 seconds, third time when the mechanic went to look at it 10 seconds,
I have read that it may be carbon deposits and to let it run to clear it up, but i don't wanna make it worse

5.3LJimmy

iTrader: (10)

It is odd for knocking to start on a cold start like that. I tend to agree with the others that have said it is a lifter that has bled down. If you have only let it run for 4, 10, and 15 seconds how do you know the warm oil pressure is 25 lbs? A rod bearing will normally cause the oil pressure to fluctuate up and down after the oil is warm, but this is not 100% accurate.

I say put a can of seafoam in the oil and let the engine idle for 20 minutes or so and see what happens. A stuck lifter should pump up by then and this will also give you a chance to monitor oil pressure after the engine gets hot. As long as you don't go for a ride or rev the engine much over idle there's not much chance of doing more damage.

If the tapping doesn't stop then another possibility is that the flywheel has cracked. This can sound like an engine knock and would explain why it happened on start up. This can be tough to diagnose but if you put the car in gear with your foot on the brake it may change the tone of the knock or eliminate it completely.

quickchrome2000

iTrader: (3)

thanks for giving me hope 5.3 jimmy, and yea i assumed the oil pressure is normal when warm, cause its normal cold when i looked at it those three times lol if that makes sense.
and the car was parked on the street so today i put in the garage, i didn't let it get warm maybe 2 minutes, when i put in on drive it did get quieter but not much.
one more thin i forgot, I had the cutout open all the time, but i closed it when i changed the oil about 100 miles back so dunno if the back pressure, and the weather being the first cold night had anything to do with it?.
oh and i did the full sea foam treatment oil, fuel and brake booster about 6000 miles back, i changed the knock sensors about 1 000 ago and I must say that the i left intake spotless, used about 4 cans of intake cleaner and some sea foam deep creep.

quickchrome2000

iTrader: (3)

ooh i didn't use all four cans to clean the intake, i meant to say clean around all the dirt and grease around where the intake plenum goes and the plenum itself, so not much of the cleaner got inside the engine

IWGF

iTrader: (6)

That sounds like a burned valve IMO, especially if you can hear it with the cutout closed... That's what happened to my friends GTO, it was weird. May wanna check it out.

bronx_peanut

Wow that was a lot of ***** for one post! lol

SOMbitch

iTrader: (8)

HIJACK: LOVE the 2nd gen BP. VERY nice

OP you can have your thread back now

KevinR

Ummmm..Not sure if I would jump straight into a rebuild if it's just the lifters.

reeperz28

iTrader: (1)

My buddys o2 m6 camaro had a bad knock and ran like poo I bought the old engine from him and tore it apart found a gaulded piston he bought a new crate ls1 installed it with headers and a borla dumped in a t56 car made 349 hp and 364 torque with the tune car was kick *** after all wass done

Adamcc91

See theres your issue.. you drove it like a grandpa...you need to let the engine breathe for it to respect you