Oil Leak from Part #21 on Diagram

[my12by60]

https://www.ebay.com/itm/Infiniti-NISSA ... 2553841185

I am not sure what the correct name is for part #21 as shown in the diagram in the link. The number 21 points to three different pieces. The piece that is leaking for me is the one that is the highest up in the diagram of the three. The part looks to be just sealed with RTV onto the front of the largest piece of #21. I have heard different names used to describe these pieces. Is #21 a 3-part timing cover? Or is the biggest piece the timing cover and the smaller two pieces cam shaft covers? One shop told me that the passenger side cam shaft cover can be removed and resealed by loosening the valve cover bolts, elevating the valve cover a few inches, then unbolting the camshaft cover. Another shop told me that all three pieces of #21 had to be removed as a unit because they are interconnected. Has anybody ever taken off that passenger cam shaft cover for reseal? What was involved?

[Drake57]

The head gaskets extend to seal between the large cover, and the two smaller timing covers. If the head gasket is damaged, like what happened to me, one can cut a cork gasket and glue it to the small cover, then reinstall the large timing cover. I suppose one may remove and replace only the small, I do not remember the details. My issue was on the opposite bank of what you describe..

I messed up my head gasket extensions by reinstalling large timing cover without removing the oil pan. The proper way to remove/replace timing cover is to remove the oil pan. If it is not done this way, the risk of damaging the head gasket extensions is great.

Voice of experience here, I messed mine up, and had a hard time fixing the oil leak between the large and small covers. I had leaks until I removed all covers, cut and RTV'ed 1/16" thick cork gasket to the small pieces, then reinstalled small, then large, then the oil pan. To the best of my recollection, it is possible to remove valve covers, and remove top timing covers, though IIRC timing chain tensioner travel is affected by the covers, extreme caution is advised to not loose proper timing when servicing the covers.

So long story short, remove oil pan, then large TC, wire the timing chain to hold tension, remove the leaky upper cover after removing it's valve cover, fashion/fasten 1/16 cork gasket in place of missing head gasket extension, then reinstall by reversing your steps. Simple, right?

[Drake57]

PS Second shop statement about having to remove all three as a unit is totally false, and indicates to me that they do not have experience with this repair, and that they're given to making statements not substantiated in fact. I've R & R'd timing cover of my son's Q and my own, twice.

[my12by60]

Thanks for the detail. So the three parts of item #21 are all considered "timing covers". Sounds like there is no way to just remove the passenger side small upper cover just by loosening and elevating the passenger side VCG. I had one shop that said they could do it this way without taking off all three pieces of the timing cover. They wanted $550 to do the job, which I thought was not worth it since the leak is not that bad.

[Q451990]

The method I saw used on my Q was to use a rubber hammer to slightly bend the oil pan lip to downward a bit giving space to fit the lower cover in. Then smearing the head gaskets with RTV to seal them when they were sanwiched between the covers. RTV was also added to the lip of the bottom of the timing cover where it mates with the oil pan, and then it was pulled back up in to place when the bolts were reinstalled. This was Byron at T3, so he had a lot of experience with this changing out the timing chain guides on the early Qs.