Oil Burning Woes

[JDMMA70]

So long story short I narrowed down my oil burning issue to valve seals, Im also only burning oil on one cylinder. #4 to be exact.

Compression on this cylinder is 175psi its adjacent cylinders are the same or there abouts. Leakdown for this cylinder is 5% leakage. Vacuum gauge diagnostic showed no valve guide related issue.

I just changed my valve stem seals on this one cylinder today and Im still burning oil, I will say not as bad as before but its still smoking none the less.


Did I miss anything, is there anything else I should look into? Did I perhaps install the seals incorrectly?


Help or Advice would be much appreciated.

Thanks
~JDMMA70

 

[3p141592654]

Valve seals usually harden with age, uniformly. My guess is that you replaced the worst ones, but have another 5 cylinders that are still contributing. Can I ask why you would go to all that trouble and not replace them all?

 

[JDMMA70]

The engine in the car currently was rebuilt approximately 6,000 miles ago. Via spark plug inspection none of the other cylinders are burning oil, only cylinder 4 is burning oil. So I just went ahead and replaced the seals on that cylinder only.

 

[3p141592654]

OK, that makes more sense. Did you suspect that the original seals were damaged during assembly? They certainly should not be worn out in 6000 miles.

 

[JDMMA70]

Yeah I did in fact. Every since the first crank it smoked a little but it go worse as time went on. So i figured something mustve happened during assembly. Im not sure what happened this time. All i can say is maybe i should try replacing the seals again. What else could it be?

 

[Blackmk3]

What brand seals did you use? id be more thinking its a quality issue with the seals to have failed this early after a rebuilt. I only use Toyota for this sort of component

 

[JDMMA70]

DNJ the first time. I just installed supertech valve seals.

 

[chevyguyjoe]

Could there be a nick on the valve causing the seal to tear?

 

[JDMMA70]

Its possible Ill have to check the next time I do it.

 

[CyFi6]

Were the guides replaced?

 

[JDMMA70]

I cant remember Id have to check the machine shop invoice but im certain they were. Regardless its not showing up when I do a vacuum gauge diagnostic test.