Ok so I have been leaking oil pretty bad for a couple years now and getting tired of it as it is getting worse and worse. I've determined it is coming form the inner timing cover o-rings between the cover and the block. I've already replaced front and rear VC, upper oil pan, lower oil pan and oil pressure sender so that pretty much leaves the timing cover o-rings I believe.

I've pretty much read through all the threads I could on doing this but haven't found a real good write up or anything.

Just a few questions and maybe any suggestions on doing this job. Do the VC's have to come off again to get the inner timing chain cover off? I plan on replacing the Water Pump, tensioners and guides while i'm doing this but never messed with anything to do with the timing before so am a little nervous I might mess up the timing. I've ready that after taking the outer timing cover off to make sure it is in TDC (top dead center)? Once it is in TDC then I can remove all the tensioners and sprockets and what not and I should be good then on putting everything back on?

Thanks for any advice!

 

You need to hold the cams to get the gears off, so you'd need to remove the valve covers to get a wrench on the cams. The whole job is all about patience, organization, and order. Not to mention you'll need a good sized tool box and clean garage to do the work. It'll take at least 12-15 hours to get the job done. Its a huge puzzle with lots of pieces. Keep track of everything; labeled baggies, punch holes in cardboard number the bolts on the timing cover, space to store parts removed, etc. Things have to be done in a certain order so go slow and check your progress. As long as you get the chains aligned and you don't rotate the cams or crank, the chains with go back on witout hassle. Again, go slow and check your work. No point in doing all this work, just to screw up timing.

Look up how to's for timing chain tensioner and guides on VQ35/VQ40 engines. There have been countless issues with those engines needing timing chain work. You'd probably find more info (with pics) on those than VQ30 tare downs. Obviously the 4th gen does not have the extra cam timing equipment shown in those how to's.

I used a Haynes manual and some online guides to replace the guides and tensioners in my Altima. Some steps were pretty frustrating, but its better to walk away and cool off instead of ripping your hair out or breaking something.

 

Thanks for the advice Jsutter! Do you mind if I PM you if I run into any other issues throughout this repair? Seems like you have a good idea of all this timing stuff from what I've been reading and the youtube videos I've watched.

 

I wouldn't call myself an expert but I'll do my best. I've torn down a few VQ's and like I said I had to replace all the guides/tensioners/water pump so at least I speak from experience. Just a $13 chain guide failed. Turned into $600 in parts by the time I replaced everything while I was in there. There are lots of O rings, seals, and gaskets along the way. I went OEM and bought what I needed. A master gasket kit may be a good choice.