626 LX V6-2.5L DOHC (1997)
Piston: All Technical Service Bulletins
Engine - Tapping Noise When Cold
Bulletin No.: 001/97
Issued 03/10/97
Revised 04/25/97
Category
B
Applicable Model/s
1995-97 Millenia
1995-97 626/MX-6
Subject:
TAPPING NOISE WHEN ENGINE IS COLD
NOTE:
The Warranty section of this bulletin is revised. Replace the original bulletin with this revised copy.
APPLICABLE MODELS
1995 - 97 Millenia with a KLD engine.
1995 - 97 626/ MX-6 with a KLD engine.
DESCRIPTION
A slight tapping noise may be heard at idle after cold start.
^
The noise diminishes as the engine warms up.
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The noise also diminishes as engine speed is increased from idle to 1500 - 2500 RPM.
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The noise tone changes intermittently from high to low and as a load is applied to the engine (i.e. engaging transmission).
^
The noise is similar to HLA and fuel injector noise.
^
The noise is unlike carbon knock which is most evident at 1500-2500 RPM.
Carbon accumulation on the top of the piston ring area is the cause of this tapping noise. Customers complaining of this noise should have the carbon
removed according to the instructions in this bulletin.
REPAIR PROCEDURE
WARNING:
DISCONNECT THE NEGATIVE BATTERY TERMINAL WHILE PERFORMING THIS REPAIR.
1.
Verify the complaint.
2.
Remove spark plugs.
CAUTION:
Remove any dirt or grit from spark plug bore prior to removing spark plug.
3.
Set piston No.1 at TDC of the compression stroke. Refer to the position of the distributor rotor to confirm position.
4.
Rotate crank pulley clockwise one (1) revolution.
