can valve guides cause engine smoking? I have read countless posts about people who say that their engines smoke past about 5-6 grand and all anyone has to say about it is that it is most likely their rings. I have a 92 dx w/d15b7 and it smokes past about 5 grand and all the way up to redline at 6,750. I regularly check my plugs and they are clean as a whistle. I pulled my head off a couple of weeks ago for an unrelated problem and noticed that my pistons had a nice thin coating of carbon on them and the combustion chambers on the head looked good too.
Normally if the rings are bad, the pistons, combustion chambers, and the plugs will all have a coating of thick black crap on them. this leads me to believe that my rings are OK.
Now, since I had my head off, a couple of valves were open and I grabbed them and wiggled them from side to side and they were loose as hell.
I think that the valve guides are leaking oil into the exhaust and intake ports and that is what is causing my smoke.

The engine smokes whether I am revving hard up to redline or holding steady at 6 grand. when i hold it steady at 6 grand the smoke just rolls out. At that high of an RPM the valves tend to overlap or float. This is when the intake and exhaust valve are open at the same time for a very short period of time. This is when I believe the oil is entering the cylinders and burning a little. I think the majority of the oil loss is just going into the exhaust port through the valve guide.

If you guys think that I have the right idea, let me know.
If you guys think that I am wrong, let me know.
Any help appreciated.

thanks

 

HA!

yes d15/d16's do this, most notably past 6000rpm or so, specially with more than 100'000 miles...

but it may not just be the guides (it was in the case fo a d15b i fixed...)

replacing them was the way to go, with new stem seals...

HTH,

t..

 

I am planning on redoing the whole head, new valves, springs, seals, retainers, guides, basically the works.
im gonna have a three angle valve job done and maybe I'll polish the ports my self. Don't know how much this will help but it cant hurt.

Does anybody have a new d series head they want to sell??????