Cylinder Head Exhaust Ports

[AHall]

I have a stock 93 S13 with countless miles, 300K+. Anyways I took off the exhaust manifold and noticed that the exhaust port for cylinder #1 was very dirty/oily. I believe the valve seals need to be replaced.

My question is should I try to clean the port area and can it be done without removing the cylinder head? Or should I just change the seals and the dirt/oil will be blown out over time? If cleaning is the way to go, what method should I use for the cleaning. It is a small opening and I suppose I would need to somehow vacuum out any debris after the cleaning.

Also do you suggest Nissan manifold gaskets or something from like a Autozone? The Nissan gaskets are like $11/each and there are four.

[compactfean]

Just use autozone/ csk gasgets. Most likely felpro makes them for nissan anyways. Usually valve guides and valve seals go hand in hand, when it comes to needing work. My machine shop charged me less than $100 to resurface the head and put bronze k liners in, for exhaust valve guides. With that many miles on it, I would be going through everything in they head. As for the cleaning, its pointless. after fired up without a leak, it will burn right out. If you get the head machined and valve guides done, they will hot tank it anyways.

[moso]

you cant really clean the valve stems through the port area effectively, and if the stem seal is bad compact is right it will just leak again. The fact of the matter is at 300k your due for a full rebuild, top and bottom end.

[compactfean]

^

[AHall]

Total rebuild?

I would hate to have to remove the head, let alone the entire motor to do a complete rebuild. I was planning on just doing the seals though and not the valve guides. I could swing $100 though, but then I would need a head gasket and who knows what else.

The car runs great, I just have to get past emissions every year. If I can just get by for another 5 years I am good.

[compactfean]

They only make band aids so big. If you can rebuild a motor yourself, a complete rebuild wouldnt hit the pocket book to hard. Especially since there isnt any damage. So you are going to attemp to put another 50-60k miles on it with just valve seals? Your gonna give yourself a headache in the long run.

[AHall]

My thinking is that I have put 300K on the car with the original seals. So is it not possible I could squeeze out another 50-60K? I believe the oil residue may be finding its way into the EGR valve coming off the exhaust and reducing the back pressure that opens the BPT so that vacuum can flow through the BPT to the EGR valve.

[spank044]

My KA had 398K on it when I rebuilt it and everything was still within spec. It had good compression and good leak down numbers. If you have the ability to remove the cams, shims, and buckets to replace the seals, then do it. If is more than possible you just need seals.