in an attempt to reduce oil consumption (1q 1000 apx) I decided to replace the intake guide seals. I decided to only to the intakes since its not an easy task and I figure the exhaust side would not suck oil anyway. Based on the condition they have been I would think its prob not going to help anyway since the old ones seem pliable, but maybe a bit larger diameter where the valve stem seals.
I was going to do a video but that is just too hard to capture so I thought I would share my process.
removed the valve cover, and all the plugs. used a 19mm on the camshaft bolt to turn the lobes with the intake lobe straight up, this is past TDC on the piston stroke.
used some rubber hose that just fits into the plug hole, then used my seal puller pliers to choke up on it near the plug hole so I can push it in it will not go any more. The pliers help grip in close to the hole so you don't have the hose bending while trying to stuff it in.
rotate the camshaft back so the lobes are "bunny ears" this will push the piston up to TDC and really jam the hose up against the valve. I forgot to mention I used the natural bend in the hose and aim for the intake valve.
loosen the rockers jam nut and run the pivot all the way down. remove the rocker arm retainer spring, the pry off the rocker from the pivot. I used the 17 mm wrench handy to lift up on the back of the rocker near the pivot. I suppose you could also just depress the valve spring a bit to. Just make sure you keep up with the lash pad. It will prob stay over the valve but stil...
with the rocker out of the way use the OHC valve spring compressor, the kind that hooks around the cam shaft (not the lobes) and has a pivot point that allows for downward pressure on the valve spring. You may want to give the top of each valve spring a light smack with a large drift to loosen up the retainers.
while depressing the valve springs use a magnet on a stick (small) and retrieve the two retainers. with them out the spring release to its full height. While doing this its a good idea to watch the valve stem it may move downward some, but if the hose was set right it will be very little. the less movement the better since you do not have to depress the spring as much.
remove the spring assy (two springs an inner and outer and a cap, keep up with the lash pad (get that out before attempting the retainers with the magnet). watch out for a spacer that sits on the bottom of the spring stack, it prob will stay on the top of the head, but you want to make sure as you remove the springs.
now the easy part use the valve stem seal puller pliers to remove the old seal, just grab it mid section and gently pull up. Careful here as the pliers will want to jump up and you are right next to the cam lobe, just don't want to scratch anything.
I soaked the new Nissan seals in some motor oil to install, then use the pliers above to push it into place. you can see when it bottoms out.
replace the valve springs, setup the spring compressor, replace the retainers (yea just like that, presto). the retainers can be a bit of a pita. I used some hemostats and would set one in place from the driver side, ease up on the compressor while rotating the retainer around so the next one will be easier to go in. A single retainer once set will hold it together while you get the next retainer setup on the hemostats. I tried for a 10/4 or 2/8 position as this was where they were when I started. You may want to look make note of this for yourself.
anyway after some fiddling with the second retainer it will just drop in an your are done. replace the rocker and reset the lash.
Have fun!!