The vehicle is a 1990 Nissan Pathfinder with a VG30E engine. 2 of the bolts at the rear of the exhaust manifold are broken on the passenger side. The vehicle has been this way for 2 years. I understand this is a common problem for this specific automobile. There is a Nissan Technical Service Bulletin number NYB94-041 on this problem I am trying to acquire. Is exhaust manifold warped or could the cylinder head be warped from the heat leak over two years. Replacing the bolts and gasket did not eliminate the problem. Ideas?
Last edited by a1brianr (6/3/2010 7:11 PM)
It doesn't seem likely that the head would warp with out having a coolant leak. It is possible that the head area at the exhaust leak could be worn away. A visual inspection will determine that. The new manifold gasket should take up and seal any minor wear on the head exhaust surface.
The service bulletin states that the broken studs should be replaced with the manifold.
This is what I got from the bulletin.
TECHNICAL BULLETIN NTB94-041
April 14, 1994
BROKEN EXHAUST MANIFOLD STUD
Only Those Equipped w/VG30E Engine
Maxima (J30 and U11)
The exhaust manifold stud has been changed for improved durability. Use the following procedure to repair vehicles which exhibit excessive exhaust noise due to exhaust manifold stud breakage.
Remove the exhaust manifold on the side of the engine with the broken studs.
Replace the broken stud (s) and the front and rear studs using the improved part number, P/N 14065-V5003.
Replace the exhaust gasket and exhaust manifold with new parts. Refer to the EM section of the appropriate service manual for the proper torque values for the fasteners.
Hope this is helpful. If you need anything else let us know.
Last edited by TechHelp2 (6/3/2010 8:58 PM)