jj big shoe Posted August 25, 2007 Share Posted August 25, 2007 (edited) Some info I stumbled upon. Here's the link to the original page which has some info on other Nissan engines. AERA=American(?) Engine Rebuilders Association Recessed Intake Valve Seats On 1990-91 Nissan 3.0L VG30E Engines AERA members have reported valve seat recession on 1990 Nissan 3.0L VG30E engines. Symptoms include intermittent misfire, hard starting and lack of power. In most instances this recession is noticed during the 60-80,000 mile period. Diagnosing these symptoms using cranking compression tests has proved to be inconclusive, as successive tests have shown different results. Cold and hot engine temperatures also exhibit varying symptoms as the engine warms up and valves do not fully close. The reported cause of this condition is an unseated intake valve, resulting from valve seat recession. Apparently the valve seat alloys used during 1990-91 model year were not properly comprised. The earlier and later engines do not seem to exhibit this condition. To repair this type of condition properly, replacement of all intake valve seats and usually all intake valves is necessary. The AERA Technical Committee Engine Coolant Leaks On 2000-02 Nissan 3.3 VG33E Engines The AERA Technical Committee offers the following information regarding an engine coolant leak on 2000-02 3.3 VG33E engines. Customers may complain of engine coolant under the vehicle if sitting for a period of time or the smell of coolant when the engine is warm. A leak between the intake manifold and the water outlet housing as shown below in Figure 1 may be causing this condition. Visually inspecting this area could verify that this is the source of the leak. To cure this problem, Nissan offers a revised fiber gasket, Part #11062-9Z000, to be installed between the water outlet and the intake manifold. When changing this gasket, make sure that you have drained the coolant just below the level of the water outlet. This will keep coolant from spilling when removing the housing. Clean the sealing surface of the water outlet housing and the intake manifold to get rid of any old sealer that may be present. Install the two mounting bolts through the outlet housing and then slide the fiber gasket over the bolts until it is flush with the sealing surface of the housing. Once the housing is installed onto the intake manifold, tighten the mounting bolts to a torque of 12-15 ft/lbs. Refill the cooling system and run the vehicle to verify that there are no further coolant leaks. The AERA Technical Committee Edited August 25, 2007 by jj big shoe Link to comment Share on other sites More sharing options...
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