Engine noise at cold start up
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From: Zurich - Switzerland
Engine noise at cold start up This is a 98 LS1 engine with 60'000 miles on it.
Stock internals, ATI armonic balancer to drive a 6 PSI Vortech.
In the morning (especially in winter) the idle is quite, but as soon I move I hear a metallic sound from the engine bay. Like clack clack clack...
This between 1000 and 2000 rpm. At higher engine speed either it's gone or it's covered by other noises, so I don't know.
Once the engine is warmed up it's fine, I can hear something but then it sounds normal to me.
Once I removed the serpentine belt, hoping it was from some accessory: it was better but not completely gone.
I have a fiberglass hood with heat extractors (Suncoast Creations) and the sound comes out from thise openings, so I may hear things you normally don't notice with the stock steel hood.
Is it normal?
How can I find out what it is?
How do I know it's bad before I brake something?
At idle it's quite, so I can't even use a stetoscope. Also if it's in neutral at 1000 - 2000 rpm it's quite: it has to have some load.
Any idea?
Thank you - Stefano
Stock internals, ATI armonic balancer to drive a 6 PSI Vortech.
In the morning (especially in winter) the idle is quite, but as soon I move I hear a metallic sound from the engine bay. Like clack clack clack...
This between 1000 and 2000 rpm. At higher engine speed either it's gone or it's covered by other noises, so I don't know.
Once the engine is warmed up it's fine, I can hear something but then it sounds normal to me.
Once I removed the serpentine belt, hoping it was from some accessory: it was better but not completely gone.
I have a fiberglass hood with heat extractors (Suncoast Creations) and the sound comes out from thise openings, so I may hear things you normally don't notice with the stock steel hood.
Is it normal?
How can I find out what it is?
How do I know it's bad before I brake something?
At idle it's quite, so I can't even use a stetoscope. Also if it's in neutral at 1000 - 2000 rpm it's quite: it has to have some load.
Any idea?
Thank you - Stefano
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From: Zurich - Switzerland
Is it possible that it's only one lifter? The noise has the same frequency as the engine speed and if they were all the lifters it would sound like a concert!
The thing is that I hear it only under load what is hard to simulate when the car is not moving.
How would a broken bearing sounds? Like those on the connecting rods?
The thing is that I hear it only under load what is hard to simulate when the car is not moving.
How would a broken bearing sounds? Like those on the connecting rods?
all LS1's do it, my car does it, all my friends LS1 F-bodies, my friends 2000 C5. i know its difficult to over look, but its what you have to do. I hate hearing it everyday, i always think there is something wrong. You are best letting the car warm up on Cold day before driving it. On warmer days it wont be as bad.
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From: Lombard,IL
its lifter noise, i just replaced all mine at 34,000 with comp oe lifters, and the noise is still there when its cold out, but as soon as the motor and oil warm up my motor is back to being quite.
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Lifters... we have 16 of them. I have the impression I hear a "clack" only each rotation.
Is there a way to be sure it's the lifters?
If it was something else would I notice it somehow? Like KR? Or misfire? Or different LTFT from bank 1/2? The rings should be OK: also under boost I don't see the typical "broken rings" problems (overpressure in the crankcase, puffing fron the oil cap).
Should I make a compression test?
Exhaust gasses are ok also (here we have to check them once in a while). It's CO, CO2, NOx, hydrocarbons.
At every oil change there is some metal mesh on the magnet of the drain bolt, is it normal?
Since I installed the blower a couple of things have changed and the car isn't as perfect as before: front engine seal is leaking (after the ATI balancer), the new Bosch injectors are very noisy (click click click), the A4 tranny is gone, the rear end is noisy and the engine also makes this strange noises...
So now I'm scared of everything that is unusual
Is there a way to be sure it's the lifters?
If it was something else would I notice it somehow? Like KR? Or misfire? Or different LTFT from bank 1/2? The rings should be OK: also under boost I don't see the typical "broken rings" problems (overpressure in the crankcase, puffing fron the oil cap).
Should I make a compression test?
Exhaust gasses are ok also (here we have to check them once in a while). It's CO, CO2, NOx, hydrocarbons.
At every oil change there is some metal mesh on the magnet of the drain bolt, is it normal?
Since I installed the blower a couple of things have changed and the car isn't as perfect as before: front engine seal is leaking (after the ATI balancer), the new Bosch injectors are very noisy (click click click), the A4 tranny is gone, the rear end is noisy and the engine also makes this strange noises...
So now I'm scared of everything that is unusual
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Verdad Gallardo It is just noisy. Cars will do it from the factory. It is just because of expanding and the pistons and the rings fittament will alter between cold and normal operating temps. (i believe)
It isnt like an actual "beating" even though it sounds severe.
Certain types of oil have been known to cause/fix the problem.
It isnt like an actual "beating" even though it sounds severe.
Certain types of oil have been known to cause/fix the problem.
Last edited by orangeapeel; Feb 9, 2006 at 06:17 PM.
