valve seal replacment
 

Well, It's looking like I need to finally replace my valve seals... My car has been progressively burning more and more oil under low load high rpm, and high vacuum situations. The compression is fine (190-200 across) so the compression rings are good but vacuum is somewhat low. I guess it could be the oil seal rings, but that again is doubtful. I'm wondering if anyone on here has replaced their valve seals without removing the head so just by removing the cams, springs and rocker arms. Removing the head is out of the question since that would take a lot more time which I really don't have. I'm really wondering if this is something I should do myself, or spend a few hundred bucks to have it done professionally. If you have any experience replacing them please post ;) (Vinnie?) Thanks guys

smoke upon start up is tell tail sign of bad valve stem seals. i've replaced them on 2 different engines from different manufactures and it's rather straight forward. as you've said the cams, spring, rocker arms and such will all have to be removed. there are two ways to go about it, one is to use an air compressor to hold the valves up when the retainers are removed the other is to use the piton itself but i recommend the latter.

you'll need to bring the piston to it's lowest point (bdc) since that's when the valves are closed. insert the air fitting into the spark plug hole and remove the valve retainer, spring and so forth. then just move to the next valve. here an additional tip for you do cylinders 1 and 4 then 2 and 3.

after you've done all that you'll need to set the cam gears to the proper location and hope you didn't skip a tooth. i've never done this on a nissan engine but the procedure if fundamentally the same. if i wasn't clear let me know and i'll try to elaborate.

Thanks for the input. I read up on it a little bit but couldn't find much on the kade specifically. The air compressor method seems like the way to go though. I'm almost positive it's the valve seals... turbo is fine for sure. I know replacing them is something I can do, but I guess now I'm just trying to figure out if I should actually do it myself. The s14 is unfortunately my only vehicle so down time can't be more than a few days.

i know what you mean i had to buy another car just so i could work on my 240. like is said it's not complicated. it's just a matter of having a suitable spring compressor, air compressor, and not letting the timing chain fall into the oil pan. above all make sure you do it right the first time and don't rush it. but if you are not up to it you should probably have a trust worthy mechanic do it for you.

Thanks again. I'll go ahead and do a leakdown before I decide who's going to do the job. I forgot to mention, It does occasionally burn oil during start up (esp. if I run the a/c), but generally it's after it's warm and I've gone down a hill at high rpm, or while reversing. I use 10 weight oil which helps a lot