2004 Quest VQ35DE timing components and water pump replacement

Messages
5
Location
Pine Grove, PA
I have the front timing cover removed, finally, on my newly acquired 2004 Quest SE. I am replacing the primary tensioner, slack guide, top guide and water pump. I have watched a few DIYs on this but still have some concern on the sequence to use and the rotation of the chain. I know to have the chain set at TDC to begin. These instructions and the Nissan manual have me confused.
https://www.brakeandfrontend.com/nissan-vq35-series-water-pump-chain-driven-water-pump-replacement/
Its stated to rotate 20 degrees CCW for slack on water pump side and then 20 degrees CCW for slack on tensioner side. This is confusing to me, has anyone done this job and have advice? I don't want to lose timing by having the engine flop/rotate with slack in the chain.
 
Messages
1,945
Location
Ontario, Canada
My guess is that the chain slack of 20 degress that will be taken up by the tensioner is on the same area (side) as the water pump. I've done timing chains and belts before but not this particular one. Hope I never have to do my VQ. Good luck!
 
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Messages
2,923
Location
Kentucky
This is what I recall from when I did the water pump on my VQ30:

If the chains are installed and you're servicing / installing the water pump and/or tensioner, you can rotate the crank to create slack on either side, which you'll use to install or remove said components. The assumption is that you don't rotate so much that you're actually turning the cams with the crank. Without the tensioner or water pump installed I'm not sure if it's possible for the chain to skip, but you don't want to turn it enough to find out. Once the chain is taut on one side and you've created the slack you need on the other, you're done turning.
 

schuylkillcounty

Thread starter
Messages
5
Location
Pine Grove, PA
So my worst fears about this water pump replacement somehow came to fruition, now I need input on recovery method. I removed the tensioner with chain set at tdc. All the marks were in their correct positions. I have the front timing cover removed, engine in van. I removed the tensioner then rotated engine ccw about 20 deg. and slack was created in the chain at the water pump. But it wasn't enough to clear the body of the pump. I carefully I thought I tried get more slack by rotated slightly more and ping sound and I knew I was screwed. I was able to get in the pump but now the right side cams are out of time. I believe that's #2 bank, by the firewall. I put the tensioner back and I can rotate the engine without any binding or noises. When I set the crank again at tdc the left side cam marks are perfect, only right side is out. So I removed the tensioner again, and with the top guide removed I can remove the main chain off of only the #2 bank which is out of sorts. My plan is to remove the intake and valve cover on that side and then rotate the cam shaft until it is in the correct position according to the marks by the camshaft itself once I learn how to understand that. I wanted to replace the valve cover gasket anyway but only bought the left side for starters because I can see it is leaking and it's accessible. Well now I will be doing both. I guess I should pull them both to work on this timing problem, want to make sure I get it right but also want to do minimum work necessary. Should I worry about the main chain not being in the correct position on the sprockets I am wondering too.
Anyway I'll be looking around for advice while I work on getting the intake off first. This is definitely my project van now.

And I want to know what I did wrong with the water pump replacement. Man!
 
Messages
1,841
Location
RI
As long as the cams are in time with the crankshaft on both banks you should be fine regardless of where the chain is. There should be colored links to make this easier to set up.
 
Messages
3,070
Location
pa
glad to hear that! seeing pics of the front of my 4.0 VQ 40 it will not be a DIY if needed. my VW 1.8T + now audi TT 1.8T were much simpler!!
 

schuylkillcounty

Thread starter
Messages
5
Location
Pine Grove, PA
Any advice on best method for installing valve/rocker cover gasket, particularly on adding the silicone sealant required at the two corners. How do you do it? I've done this maybe once before and don't recall how it went. That was on a Nissan also, Sentra.
 
Messages
2,063
Location
Jupiter, Fl
You should look in the service manual, Nissan manuals are available for free. As I recall, a dab at any right angles, or where the gasket direction changes to vertical. So at the front, dabs in the two corners where the head and the timing gear cover meet - where the gasket has to turn upward, with all surfaces clean and dry. I've heard some people say they apply a small amount to keep the gasket in place in the valve cover when they are putting them in place, but I don't think that is the approved method.
 
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