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There are a few O-rings that seal the passages that supply oil to the CVTC variable cam timing mechanism. These get hard and deformed. If you try to reuse them they will leak and you will lose cam control. The engine will run like crap and you will get all sorts of check engine lights and maybe the car will go into limp mode. Then you have to disassemble a whole bunch of stuff to fix it all. When bolting on the most forward cam cap also make sure you put the sealer on correctly mimicking the factory sealer. Don't overdo it or the stuff can get squished into oil passages causing disaster.
This is the infamous VQ cam drive chain tensioner that causes a lot of problems in some cars. Nissan has changed the design of this part and if yours is worn change it for the new updated parts. Some cars like ours have no problems and very little wear. Others eat this part. Ours was in great condition so we left it.
The VQ uses tons of sealer to seal the front of the engine up. Here Howard applies Permatex grey sealer to all of the places in the front of the engine. Mimic the factory seal and do a good job of doing this all exactly right. Do not overdo the sealer of it will migrate into oil passages and cause big problems. Do not forget anyplace or you will have big problems. Refer to the factory service manual if you are not sure what you are doing.
Here is the front cover ready to go with all the sealer in place.
After carefully placing the front cover so as not to mess up the sealer, Howard starts putting the millions of little bolts that hold the cover on back in place.
Howard torques the bolts carefully with an inch pound wrench.
