Burning oil and A/F readings?

[67Charger]

I have 2 separate engines that burn a little oil due to leaking valve stem seals. One is horrible if it sits, but clears up after about 5 minutes. The other is persistent but light.

Does the burnt oil affect the O2 reading in real-time, or is it just damaging in the long term?

 

[Don Frelier]

Sorry don't know the answer about the O2 readings.
But why don't you change the seals?
It's not that difficult.

 

[67Charger]

Sorry don't know the answer about the O2 readings.
But why don't you change the seals?
It's not that difficult.

The one that is bad at startup after sitting is a 392 International. They are notorious for it, and even when good, they're not that great. Fixing the seals is on the list, but hasn't made it to the front yet. The other one is a slant 6 with some miles on it.

 

[Don Frelier]

I see, well depending on the condition of the guides you could quick do the exhaust valves they are usually the culprit.
If you put rope on the cylinder and remove the spring you can roll the piston down a little and allow for a little downward movement and see how loose the guide is.
You can't do that if you use the air pressure method.
Depending on what you find for this test you can then decide if it's worth putting seals on the head.
The slant 6 should be fairly easy.

 

[PurpleBeeper]

And any oil getting onto your oxygen sensors would prevent them from reading correctly, more from being "gummed up" than anything.