i have a 66 289. I poured water through the carb, to clean out the carbon. The plugs looked clean for a little while and now there covered in oil again. I believe it's the original 50,000 miles on it and im ruling out piston rings, unless there stuck and not rotating. has this happened to you, could it be bad valve stem seals?

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usually the stem seals, does it smoke alittle when you crank it up in the morning then stop? tell tale sign of stem seal probs.

 

yes, it smokes alot when it's first started, then it eases off alittle. When i did a compression test it was around 120 psi on all cylinders but the number 1, it was about 100 psi, if i remember correctly

 

it sounds like bad valve stem seals to me also and BTW, piston rings don't rotate either. I would also take a look at the valves on the #1 cylinder since the compression was so much lower there than on the other cylinders. could be a burnt valve.

 

compression is low all around too, if you did the test right then its probably time for a complete overhaul.

 

yeah, i took out all the sparkplugs and it read 120 psi i believe. I couldn't have done it wrong. I guess it just need to be rebuilt. Well it's still running strong, so im gonna put that off for a little while.

 

my bad I was thinkin it was 100 on most of em... 120 is ok for a low comp motor I suppose... but a 20% diff in one cylinder is bad - like the great round one said something isnt right there. but yea I feel ya on the rebuild... as long as its still runnin lol

 

i figured something was bad on that number one cylinder, but they all got oil on them, so it doesn't matter. Least 120 psi isn't real bad. i might look at that one day. I'll prob. have to get a set of valve cover gaskets. Thanks for all the info

 

you could squirt a little oil on #1 cylinder to see if the compression increases,and you should have a 7% average across all cylinders.

 

hold up......is the oil on the threads? u might have a bad pcv? valve covers vented?