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Can you tell me if there is an updated exhaust manifold torque specification for GEN III engines?

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The AERA Technical Com-mittee offers the following information regarding exhaust manifold bolt and torque update on 1998-2003 GEN III 4.8L, 5.3L, 5.7L and 6.0L engines. A new exhaust manifold bolt and torque specification was introduced to the GEN III Vortec small block V8 engines beginning with model year 2004. When servicing any of the GEN III small block exhaust manifolds, the exhaust manifold bolts should be replaced.

These exhaust manifold bolts can be purchased from GM using p/n 11518860. When installing the bolts into the mounting hole, apply a .200" (5 mm) wide bead of high temperature thread locker to the threads of the exhaust manifold bolts before installation. GM thread locker compound part numbers are p/n 12345493 (US) and p/n 10953488 (Canada).

Tightening the exhaust manifold bolts should be done in two passes. First, tighten the two center bolts on the exhaust manifold. Then, tighten the rest of the bolts alternating from side to side while working towards the outside bolts.

During the first pass, tighten bolts to 59 in.lbs. Then, on the final pass, tighten the bolts to 15 ft.lbs.

Is there more than one type of main bearing thrust washer for Chrysler 3.5L engines?

The AERA Technical Com-mittee offers the following information regarding a main bearing caution for 1993-2006 Chrysler 3.5L VIN F, G K, M & V engines. These engines use two different styles for controlling crankshaft end thrust. One style is a flanged thrust bearing and the other is a thrust washer arrangement.

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The cylinder blocks are also different to accommodate the specific style of thrust control bearing. Careful examination of the bearing type before inspection and parts ordering will prove beneficial as some aftermarket bearing suppliers only provide one style thrust.
As described in most catalogs, early engines use the flanged thrust bearing, while 1999 and later engines use the thrust washer design.

Some of our installers have complained of coolant loss on 6.0L Ford engines. Any solutions?

The AERA Technical Committee offers the following caution on coolant loss for 2002-2006 Ford 6.0L VIN P diesel engines. This caution comes after numeruous reports of head gasket replacement due to loss of engine coolant.

Some engine builders have attempted to replace head gaskets in an effort to repair these coolant leaks. While in many cases doing so is the most effective repair, loss of coolant in this situation is not due to the head gasket.

These engines use an EGR cooler, which has been found to leak after a period of time, leaking engine coolant into the intake manifold. Replacement of the EGR cooler assembly has resolved the coolant loss in most cases.

Chart 1 Thrust bearing type and size information for 1993-2006 Chrysler 3.5L engines.

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