Bronco L6-300 4.9L VIN Y 1-bbl (1983)
EGR Valve: All Technical Service Bulletins
EGR Valve/Engine - Piston Slap
Article No. 83-23-14
NOISE - PISTON SLAP - (4.9L) COLD DRIVEAWAY UNDER LIGHT LOAD
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VEHICLES UNDER 8500 LB. GVW - ALL CALIBRATIONS
LIGHT TRUCKS 1981-83 E & F SERIES & BRONCO
CALIBRATIONS: All (3-52F, 3-52G, 3-52K, 3-52S, 3-52T, 3-52V should only use Step B)
Some units may experience a piston slap noise during cold engine high speed and light load conditions. The noise will usually occur within the first 2
miles of operation. The following procedures should resolve this concern. Perform vacuum schematic changes as noted for cold drive trickle EGR. Then,
if necessary, replace pistons if the concern is not resolved.
Step A All 1981-83 vehicles except 1983 AOD calibrations 3-52F, 3-52G, 3-52K, 3-52S, 3-52T, 3-52V. These calibrations should only use Step B.
Figure 8
1.
Assemble a vacuum harness as shown in Figure 8.
2.
Locate the EGR valve and remove the vacuum hose from the valve and connect it to the "C" end of the harness assembly.
3.
Connect the "B" end of the harness assembly to the EGR valve.
4.
Remove the hose from the carburetor EGR port and connect the "A" end of the harness to the EGR port.
5.
Connect the hose that was removed from the EGR port to the other side of the "A" end of the harness.
