valve seals, or guides

[dragxs11]

For several years now I've been burning oil due to bad oil seals or guides, or both. I was wondering, do you guys think that I'm only in need of new seals, or do the valve guides typically wear out by 50k miles? If I could get by with just seals, that would keep my head out of the machine shop(less down time ).

[chevy45412001]

just my thoughts

Hey drags, if it were me i think i'd have to go the whole nine yards.If it were already apart just do the head complete,Why take it apart two or three times if you don't need to?(meaning, valves today, seals next week, guides in a three weeks,port and polish week after that.....) you get the point.Just what i'd do. Good luck in whatever ya decide.

[TopCatGr58]

Hey Chevy, and Dragxs11,

I remember reading about only 1 person on the Forum that had problems with a leaking valve guide, and replaced it, but it was a real PITA to do it!! I've rebuilt my topend(big bore) after an estimated 40+kmiles, just replaced the valve seals, the guides were in great shape. I think it was John who just did a complete rebuild with big bore, new bearings and such, but don't remember him mentioning replacing his valve guides.

Those things do use an O-ring for a seal, but are pressed in there pretty firmly, and I would suspect that unless the valve guide has come loose/shifted/dropped, that they are probably still sealing well, and that his valve seals are the culprit.

I know how to check valves for leaking, but not sure how to check valve guides? Any hints here Ken/Sooke, others? That way he could take it apart as planned, and if the guides aren't messed up or leaking, then he can confidently proceed with just replacing the valve seals!
T.C.

[DEmily]

TopCAt, I think I was the one that you may be thinking of. My valve guide was leaking, but only because the cam chain jumped and the valves bent damaging only on of the guides. It was a bear to get in as the size that was sold was one size over and the head that I have had no wear, so the fit was way to tight.
I would have a tendence to say: If the valves have never been bent from piston contact, then I would simply put in valve seals.

[MartyA]

If I remember driveway motor repair 101-

Oil smoke all the time is piston hole or major ring problem.
Oil smoke mostly under hard acceleration is rings.
Oil smoke mostly when decelerating is valve seals.
Oil smoke mostly at startup is valve seals.

These are generalizations, of course. There are probably more.

[dragxs11]

Thanks guys, I know it's in the head cause it smokes on deceleration, and at idle. I just talked to my mechanic a couple days ago, and he said that he replaced the valve seals when he put in the big bore kit. Not sure I believe him. But never-the-less, the head will have to come off again to see whats wrong