Z06 Engine Noise Solved
Thread Starter
Burning Brakes
Joined: Jun 1999
Posts: 1,028
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From: La Jolla, CA
Z06 Engine Noise Solved
The answer is here: http://forums.corvetteforum.com/zerothread?id=503410
[Modified by johnC5, 4:57 PM 2/28/2003]
[Modified by johnC5, 4:57 PM 2/28/2003]
Former Vendor
Joined: Apr 2001
Posts: 10,976
Likes: 21
From: FL
St. Jude Donor '13
Re: Z06 Engine Noise Solved (johnC5)
John,you may find this new document interesting ;) Those after APRIL of 2001 got the new tighter fit coated pistons :yesnod:
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Engine Knock on Startup (including Hot Re-Starts) on LS1 V8 Engine #PI00150 - (02/12/2003)
Engine Knock on Startup (including Hot Re-starts) on LS1 V8 Engine
.
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
Condition/Concern:
Engine knock on startup (including hot re-starts) on LS1 V8 engines built after April of 2001
Recommendation/Instructions:
Determine if a piston is making the noise by shorting out the fuel injectors to individual cylinders. After determining which cylinders are the source of the knock noise (90% of the time it should be #1) eight standard size pistons may be ordered through SPO.
These pistons should be measured with the largest piston going in the noisy bore, and the next largest going into #1 bore and #8 bore, in that order. If measuring equipment is unavailable, most machine shops should have the capability of determining piston size.
The new piston will come with rings, but they are not to be used. The rings should be removed from the old piston, and install on new piston in the position they were removed to prevent oil consumption. Do NOT dress the bores! Care should be taken to assure the old rings are re-installed in the same position in the same bores as they came out of. Document ID 195097 describes the piston and connecting rod assemble procedure which requires the use of heat during dis-assembly and re-assembly. HEAT MUST BE USED DURING DIS- ASSEMBLY AND RE- ASSEMBLY TO PREVENT PISTON DAMAGE and/or rod distortion.
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Engine Knock on Startup (including Hot Re-Starts) on LS1 V8 Engine #PI00150 - (02/12/2003)
Engine Knock on Startup (including Hot Re-starts) on LS1 V8 Engine
.
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
Condition/Concern:
Engine knock on startup (including hot re-starts) on LS1 V8 engines built after April of 2001
Recommendation/Instructions:
Determine if a piston is making the noise by shorting out the fuel injectors to individual cylinders. After determining which cylinders are the source of the knock noise (90% of the time it should be #1) eight standard size pistons may be ordered through SPO.
These pistons should be measured with the largest piston going in the noisy bore, and the next largest going into #1 bore and #8 bore, in that order. If measuring equipment is unavailable, most machine shops should have the capability of determining piston size.
The new piston will come with rings, but they are not to be used. The rings should be removed from the old piston, and install on new piston in the position they were removed to prevent oil consumption. Do NOT dress the bores! Care should be taken to assure the old rings are re-installed in the same position in the same bores as they came out of. Document ID 195097 describes the piston and connecting rod assemble procedure which requires the use of heat during dis-assembly and re-assembly. HEAT MUST BE USED DURING DIS- ASSEMBLY AND RE- ASSEMBLY TO PREVENT PISTON DAMAGE and/or rod distortion.
Thread Starter
Burning Brakes
Joined: Jun 1999
Posts: 1,028
Likes: 0
From: La Jolla, CA
Re: Z06 Engine Noise Solved (C-5 TECH)
C5-TECH, as always, thank you very much for the tech info. This Z06 is a 2002, so it should have the new coated pistons and updated anti-flutter rings.
The main characteristic of this noise is that is does not really occur at cold start up or hot restart. It occurs when the engine is hot; it is a continuous sound that does not go away. Additionally, the sound can be heard while driving the car.
The GM rep's analysis of excess tolerance for the wrist pin in the #8 cylinder sounds plausible.
Will replacing just the piston and rod assembly be sufficient, or should the entire engine be taken apart and inspected as suggested in the Z06 thread?(this problem has been present for 7200+ miles). Questions have been raised regarding cylinder-wall damage and general bearing damage from metal particles. :confused: :confused: :confused:
[Modified by johnC5, 12:27 PM 3/1/2003]
The main characteristic of this noise is that is does not really occur at cold start up or hot restart. It occurs when the engine is hot; it is a continuous sound that does not go away. Additionally, the sound can be heard while driving the car.
The GM rep's analysis of excess tolerance for the wrist pin in the #8 cylinder sounds plausible.
Will replacing just the piston and rod assembly be sufficient, or should the entire engine be taken apart and inspected as suggested in the Z06 thread?(this problem has been present for 7200+ miles). Questions have been raised regarding cylinder-wall damage and general bearing damage from metal particles. :confused: :confused: :confused:
[Modified by johnC5, 12:27 PM 3/1/2003]
